Injection Device

Abstract

The application concerns an injection device for apportioning set doses of a drug from a reservoir ( 40 ) to a subject. The injection device comprises a housing having an interior thread ( 101,112 ) formed as an outwardly pointing thread ( 101,112 ) carried on an upstanding tower centrally located in the pen shaped device. This outwardly pointing thread ( 101,112 ) forms a first thread connection with the interior thread of the rotatable scale drum ( 90 ). The injection device further comprises a driver ( 70 ) for moving the piston rod ( 120 ) forward when moved axially. The driver ( 70 ) operates the piston rod ( 120 ) through a second thread connection having a pitch different than the first thread connection.

1 . An injection device for apportioning set doses of a drug from a reservoir comprising:
 A housing ( 10 ,  210 ,  310 ,  510 ,  610 ) adapted to hold the reservoir ( 40 ,  240 ,  340 ,  540 ,  640 ),   A dose setting member ( 30 ,  50 ,  230 ,  2150 ,  330 ,  3150 ,  550 ,  630 ,  660 ) for setting the size of the dose to be expelled,   A scale indication sleeve ( 90 ,  290 ,  390 ,  590 ,  690 ) for indicating the size of the set dose,   A piston rod ( 120 ,  2120 ,  3120 ,  5120 ,  6120 ) for activating the reservoir ( 40 ,  240 ,  340 ,  540 ,  640 ) to expel the set dose,   A drive sleeve ( 70 ,  270 ,  370 ,  570 ,  670 ) operational associated with the piston rod ( 120 ,  2120 ,  3120 ,  5120 ,  6120 ) for driving the piston rod ( 120 ,  2120 ,  3120 ,  5120 ,  6120 ) forward,   characterized in that,   the dose indication sleeve ( 90 ,  290 ,  390 ,  590 ,  690 ) is surrounded by a shield ( 60 ,  260 ,  360 ,  560 ,  660 ) through which the scale indication sleeve ( 90 ,  290 ,  390 ,  590 ,  690 ) is visible.   
   
   
       2 . An injection device according to  claim 1 , characterized in that, the shield ( 60 ,  260 ,  360 ,  560 ,  660 ) is an at least partly transparent hollow cylinder-shaped sleeve surrounding at least the major part of the drive sleeve ( 70 ,  270 ,  370 ,  570 ,  670 ) and the dose indication sleeve ( 90 ,  290 ,  390 ,  590 ,  690 ). 
   
   
       3 . An injection device according to  claim 2 , characterized in that, the drive sleeve ( 70 ,  270 ,  370 ,  570 ,  670 ) is rotational locked to the shield ( 60 ,  260 ,  360 ,  560 ,  660 ) at least when the set dose is expelled. 
   
   
       4 . An injection device according to  claim 1 , characterized in that, the shield ( 660 ) and the push button ( 630 ) is rotational locked to each other. 
   
   
       5 . An injection device according to  claim 1 , characterized in that, the shield ( 60 ,  260 ,  360 ,  560 ,  660 ) is axially and non-rotatable guided in the housing ( 10 ,  210 ,  310 ,  510 ,  610 ) by a protrusion ( 61 ,  261 ) on the shield engaging a longitudinal track ( 12 ,  212 ,  312 ) in the housing ( 10 ,  210 ,  310 ,  510 ,  610 ). 
   
   
       6 . An injection device for apportioning set doses of a drug from a reservoir ( 40 ,  240 ,  340 ), comprising:
 a housing ( 10 ,  210 ,  310 ,  510 ,  610 ) adapted to hold a reservoir ( 40 , 240 ,  340 ,  540 ,  640 ),   a dose setting member ( 30 ,  50 ;  230 ,  2150 ;  330 ,  3150 ;  550 ;  630 ,  660 ) for setting the size of the dose to be expelled,   a scale indication sleeve ( 90 ,  290 ,  390 ,  590 ,  690 ) for indicating the size of the set dose,   a piston rod ( 120 ,  2120 ,  3120 ,  5120 ,  6120 ) for activating the reservoir ( 40 ,  240 ,  340 ,  540 ,  640 ) to expel the set dose,   a drive sleeve ( 70 ,  270 ,  370 ,  570 ,  670 ) operational associated with the piston rod ( 120 ,  2120 ,  3120 ,  5120 ,  6120 ) for driving the piston rod ( 120 ,  2120 ,  3120 ,  5120 ,  6120 ) forward,   characterized in that,   the drive sleeve ( 70 ,  270 ,  370 ,  570 ,  670 ) is associated with a first thread ( 112 ,  2120 ,  3112 ,  5112 ,  6105 ) and releasable connected to the dose setting member ( 30 ,  50 ;  230 ,  2150 ;  330 ,  3150 ;  550 ;  630 ,  660 ), and   the dose indication sleeve ( 90 ,  290 ,  390 ,  590 ,  690 ) is associated with a second thread ( 101 ,  2101 ,  3101 ,  5101 ,  6101 ), and releasable connected to the dose setting member ( 30 ,  50 ;  230 ,  2150 ;  330 ,  3150 ;  550 ;  630 ,  660 ), wherein   the first thread ( 112 ,  2120 ,  3112 ,  5112 ,  6105 ) has a pitch different from the pitch of the second thread ( 101 ,  2101 ,  3101 ,  5101 ,  6101 ).   
   
   
       7 . An injection device according to  claim 1 , characterized in that, the dose setting member ( 30 ,  50 ;  230 ,  2150 ;  330 ,  3150 ;  550 ;  630 ,  660 ) is disconnected from the drive sleeve ( 70 ,  270 ,  370 ,  570 ,  670 ) and connected to the dose indicating sleeve ( 90 ,  290 ,  390 ,  590 ,  690 ) when setting a dose, and that the dose setting member ( 30 ,  50 ;  230 ,  2150 ;  330 ,  3150 ;  550 ;  630 ,  660 ) is connected to the drive sleeve ( 70 ,  270 ,  370 ,  570 ,  670 ) and disconnected from the dose indicating sleeve ( 90 ,  290 ,  390 ,  590 ,  690 ) when the set dose is expelled. 
   
   
       8 . An injection device according to  claim 1 , characterized in that, the pitch of the first thread ( 112 ,  2120 ,  3112 ,  5112 ,  6105 ) is larger than the pitch of the second thread ( 101 ,  2101 ,  3101 ,  5101 ,  6101 ). 
   
   
       9 . An injection device according to  claim 3 , characterized in that, the drive sleeve ( 70 ,  270 ,  370 ,  570 ,  670 ) is prevented from rotating in relation to the housing ( 10 ,  210 ,  310 ,  510 ,  610 ) when the set dose is expelled. 
   
   
       10 . An injection device according to  claim 4 , characterized in that, the drive sleeve ( 70 ,  270 ,  370 ,  570 ,  670 ) is coupled to the housing ( 10 ,  210 ,  310 ,  510 ,  610 ) through a shield ( 60 ,  260 ,  360 ,  560 ,  660 ) which is non-rotatable guided in the housing ( 10 ,  210 ,  310 ,  510 ,  610 ). 
   
   
       11 . An injection device according to  claim 5 , characterized in that, the shield ( 60 ,  260 ,  360 ,  560 ,  660 ) is at least partly transparent. 
   
   
       12 . An injection device according to  claim 1 , characterized in that, the drive sleeve ( 70 ,  270 ,  370 ,  570 ,  670 ) is axially connected to the scale indication sleeve ( 90 ,  290 ,  390 ,  590 ,  690 ) to follow axial movement of the scale indication sleeve ( 90 ,  290 ,  390 ,  590 ,  690 ) at least when the size of the dose is set. 
   
   
       13 . An injection device according to  claim 1 , characterized in that the first thread ( 112 ,  3112 ,  5112 ) engaged by the drive sleeve ( 70 ,  370 ,  570 ) is provided on a piston rod guide ( 110 ,  3110 ,  5110 ) rotating the piston rod ( 120 ,  3120 ,  5120 ) 
   
   
       14 . An injection device according to  claim 1 , characterized in that the first thread ( 2124 ) engaged by the drive sleeve ( 270 ) is provided on the piston rod ( 2120 ). 
   
   
       15 . An injection device according to  claim 1 , characterized in that, the second thread ( 101 ,  2101 ,  3101 ,  5101 ,  6101 ) engaged by the dose indication sleeve ( 90 ,  290 ,  390 ,  590 ,  690 ) is provided on a thread tower ( 100 ,  2100 ,  3100 ,  5100 ,  6100 ) centrally located in the housing ( 10 ,  210 ,  310 ,  510 ,  610 ) and non-rotatable connected to the housing ( 10 ,  210 ,  310 ,  510 , 610 ).