Administration device comprising a plunger rod with a return lock

Abstract

An administering apparatus including a casing, a reservoir, a piston accommodated in the reservoir such that it can be shifted in an advancing direction, a piston rod which acts on the piston in the advancing direction and forms a first locking mechanism, a second locking mechanism which cannot be moved counter to the advancing direction, a lock element row formed by successively arranged first locking elements, extending in the advancing direction, and formed by one of the locking mechanisms, and a second lock element formed by the other locking mechanism and engaged with the lock element row, wherein it engages with a lock element gap of the lock element row, wherein the second lock element is moved out of engagement by a movement, against an elasticity force, of the piston rod in the advancing direction, but, when engaged, counteracts a movement of the piston rod counter to the advancing direction with a resistance force greater than the elasticity force to prevent the piston rod from moving counter to the advancing direction. In some embodiments, either or both the first and second locking mechanisms form a securing element at one or both ends with respect to the advancing direction, the securing element counteracting a movement of the piston rod counter to the advancing direction with a locking force greater than the resistance force.

1 . An administering apparatus comprising: a casing, a reservoir, a piston accommodated in the reservoir such that it can be shifted in an advancing direction, a piston rod which acts on the piston in the advancing direction and forms a first locking mechanism, a second locking mechanism which cannot be moved counter to the advancing direction, first locking elements arranged in a lock element row extending in the advancing direction and carried by one of the locking mechanisms, and a second lock element carried by the other locking mechanism and engageable with the lock element row, wherein the second lock element is disengaged by a movement, against an elasticity force, of the piston rod in the advancing direction, but, when engaged, counteracts a movement of the piston rod counter to the advancing direction with a resistance force greater than the elasticity force to prevent the piston rod from moving counter to the advancing direction. 
   
   
       2 . The administering apparatus according to  claim 1 , wherein at least one of the first and second locking mechanisms forms a securing element for counteracting a movement of the piston rod counter to the advancing direction with a locking force greater than the resistance force. 
   
   
       3 . The administering apparatus according to  claim 2 , wherein the securing element is at one or both ends with respect to the advancing direction. 
   
   
       4 . An administering apparatus for administering a fluid product, said administering apparatus comprising:
 a) a casing including a reservoir for the product;   b) a piston which is accommodated in the reservoir such that it can be shifted in an advancing direction to administer product;   c) a piston rod which acts on the piston in the advancing direction and forms a first blocking means;   d) a second blocking means which cannot be moved relative to the casing counter to the advancing direction;   e) a blocking element row, formed by successively arranged first blocking elements, extending in the advancing direction, and formed by one of the blocking means;   f) a second blocking element formed by the other blocking means and engaged with the blocking element row, wherein it engages with a blocking element gap of the blocking element row; wherein   g) the second blocking element is moved out of engagement by a movement, against an elasticity force, of the piston rod in the advancing direction, but when engaged counteracts a movement of the piston rod counter to the advancing direction with a resistance force which is greater than the elasticity force to prevent the piston rod from moving counter to the advancing direction; and wherein   h) at least one of the first and second blocking means forms a block securing element at least one end with respect to the advancing direction, said block securing element counteracting a movement of the piston rod counter to the advancing direction with a blocking force which is greater than the resistance force.   
   
   
       5 . The administering apparatus as set forth in  claim 4 , wherein the block securing element is formed at one end of the blocking element row. 
   
   
       6 . The administering apparatus as set forth in  claim 5 , wherein the block securing element protrudes beyond the blocking element row transversely to the advancing direction and is more bend-resistant than the first blocking elements. 
   
   
       7 . The administering apparatus as set forth in  claim 4 , wherein the blocking element row is a row of teeth. 
   
   
       8 . The administering apparatus as set forth in  claim 4 , wherein the block securing element generates the blocking force either in engagement with the second blocking element or in engagement with the blocking element row. 
   
   
       9 . The administering apparatus as set forth in  claim 8 , wherein the blocking element row is formed by serrated teeth and the block securing element forms a stopper area for the second blocking element, directly at a tapered end of one of the serrated teeth of the blocking element row, wherein the stopper area points counter to the advancing direction if the piston rod forms the block securing element, and wherein the stopper area points in the advancing direction if the second blocking means forms the block securing element. 
   
   
       10 . The administering apparatus as set forth in  claim 4 , wherein the blocking elements of the blocking element row each form a stopper area for the second blocking element, in order through a positive lock to prevent the piston rod from moving counter to the advancing direction, and in that the block securing element also forms a stopper area, in order through a positive lock to prevent the piston rod from moving counter to the advancing direction, and in that the stopper area of the block securing element has at least substantially, preferably exactly, the same distance—measured in the advancing direction—from the stopper area of the nearest adjacent blocking element of the blocking element row as any two stopper areas of nearest adjacent blocking elements of the blocking element row. 
   
   
       11 . The administering apparatus as set forth in  claim 10 , wherein the first blocking means forms the blocking element row. 
   
   
       12 . The administering apparatus as set forth in  claim 4 , wherein the blocking means which forms the second blocking element also forms the block securing element and in that the block securing element protrudes beyond the second blocking element, transversely to the advancing direction, or is more bend-resistant than the second blocking element. 
   
   
       13 . The administering apparatus as set forth in  claim 4 , wherein the block securing element is a serrated tooth which widens in a slope up to a serrated tooth end, in or counter to the advancing direction, and at the serrated tooth end forms a stopper area for the second blocking element, pointing in or counter to the advancing direction. 
   
   
       14 . The administering apparatus as set forth in  claim 4 , wherein the block securing element generates the blocking force in engagement with a securing counter element and permits movement in the advancing direction beyond the securing counter element, in order that the second blocking element can be engaged with the blocking element row. 
   
   
       15 . The administering apparatus as set forth in  claim 4 , wherein the piston rod comprises a threaded section and in that in said threaded section, the piston rod comprises a cavity extending in the advancing direction, in which the first blocking means is formed. 
   
   
       16 . The administering apparatus as set forth in  claim 15 , wherein the block securing element is formed in the cavity and does not protrude beyond a root of the thread of the threaded section, transversely to the advancing direction. 
   
   
       17 . The administering apparatus as set forth in  claim 4 , further comprising a reservoir module and a dosing and activating module which is detachably connected to the reservoir module, wherein the reservoir module forms a front casing section of the casing which receives the reservoir, the second blocking means and the piston rod which is in engagement with the second blocking means, and wherein the dosing and activating module includes a rear casing section of the casing comprising a dosing and drive means of the administering apparatus. 
   
   
       18 . The administering apparatus as set forth in  claim 14 , said reservoir module comprising:
 a) the front casing section of the casing which comprises the reservoir including the piston accommodated in it, the second blocking means and a connecting means for establishing the connection to the dosing and activating module;   b) the dosage setting member which is accommodated by the front casing section such that it can move, in order to perform a dosing movement and a delivery movement which delivers the product;   c) and the piston rod which is connected to the dosage setting member and is in engagement with the second blocking means.