Dual-function spring

Abstract

An injection device for dispensing a product, the injection device including a moveable element which is moved for a dispensing operation, a spring, a product container holder and a product container, wherein the spring pushes against the moveable element to move the moveable element to an initial position after the dispensing operation has ended and against the product container to seat the product container in the product container holder.

1 . An injection device for dispensing a product, the injection device comprising
 a. a housing accommodating a drive unit;   b. a product container holder configured for accommodating a product container, wherein a plunger is moveably accommodated in the product container;   c. an output element operatively connectable to the drive unit and configured to move in and counter to a dispensing direction, wherein movement by the output element in a dispensing operation causes the product to be dispensed from the product container;   d. a coupling mechanism configured to longitudinally guide the output element and be movable relative to the housing between a first position and a second position; and   e. a bayonet fitting adapted to releasably couple the product container holder to the drive unit,
 wherein upon release of the bayonet fitting, the coupling mechanism moves from the second position to the first position such that at least a portion of the coupling mechanism is free to rotate relative to the housing, and 
 wherein coupling of the bayonet fitting moves the coupling mechanism from the first position to the second position, and in the second position and prior to the dispensing operation, the at least a portion of the coupling mechanism is rotationally locked relative to housing. 
   
     
     
         2 . The injection device according to  claim 1 , further comprising a spring, wherein when the bayonet fitting is released, the spring moves the coupling mechanism from the second position to the first position. 
     
     
         3 . The injection device according to  claim 2 , wherein when the product container holder is attached to the drive unit, the spring cooperates with at least a portion of the coupling mechanism to secure the container in the product container holder. 
     
     
         4 . The injection device according to  claim 1 , wherein the coupling mechanism comprises teeth disposed on an outer surface for rotationally locking the at least a portion of the coupling mechanism in the second position. 
     
     
         5 . The injection device according to  claim 1 , wherein a movement of the product container holder relative to the drive unit during coupling of the bayonet fitting involves a combined rotational and axial movement followed by non-axial, rotational movement of the product container holder relative to the drive unit. 
     
     
         6 . The injection device according to  claim 1 , wherein the coupling mechanism comprises a coupling sleeve, a threaded insert and a guide sleeve. 
     
     
         7 . The injection device according to  claim 1 , wherein a portion of the coupling mechanism is threadedly engaged with the output element. 
     
     
         8 . The injection device according to  claim 1 , wherein a portion of the coupling mechanism locates in a longitudinal groove of the output element. 
     
     
         9 . An injection device for dispensing a product, the injection device comprising a. a housing accommodating a drive unit;
 b. a product container holder configured for accommodating a product container, wherein a plunger is moveably accommodated in the product container;   c. an output element configured to move in and counter to a dispensing direction, wherein movement by the output element in a dispensing operation causes the product to be dispensed from the product container;   d. a coupling mechanism configured to longitudinally guide the output element and be movable relative to the housing between a first position and a second position;   e. a spring arranged in the housing; and   f. a bayonet fitting adapted to releasably couple the product container holder to the drive unit,
 wherein upon release of the bayonet fitting, the spring forces the coupling mechanism from the second to the first position, and in the first position, at least a portion of the coupling mechanism is rotatable relative to the housing and permits the output element to rotate in and counter to the dispensing direction, 
 wherein upon coupling of the bayonet fitting, the coupling mechanism is in the second position such that the coupling mechanism: i) cooperates with the spring to urge the product container into a fixed seating with the product container holder, and ii) prevents the output element from rotating relative to the housing prior to the dispensing operation. 
   
     
     
         10 . The injection device according to  claim 9 , wherein the coupling mechanism comprises teeth disposed on an outer surface for rotationally locking the at least a portion of the coupling mechanism in the second position. 
     
     
         11 . The injection device according to  claim 9 , wherein a movement of the product container holder relative to the drive unit during coupling of the bayonet fitting involves a combined rotational and axial movement followed by non-axial, rotational movement of the product container holder relative to the drive unit. 
     
     
         12 . The injection device according to  claim 9 , wherein the coupling mechanism comprises a coupling sleeve, a threaded insert and a guide sleeve. 
     
     
         13 . The injection device according to  claim 9 , wherein a portion of the coupling mechanism is threadedly engaged with the output element. 
     
     
         14 . The injection device according to  claim 9 , wherein the output element has a longitudinal groove and a portion of the coupling mechanism locates in the longitudinal groove of the output element.