Injection device with torsion spring and rotatable display
First Claim
1. An injection device comprisinga helical torsion spring (12) operatively connected to a dose setting member (1), the dose setting member (1) being adapted to set a dose to be ejected from the injection device, anda rotatably mounted display member adapted to display the dose to be ejected from the injection device in accordance with a setting of the dose setting member (1), the rotatably mounted display member being rotatable over an angle corresponding to at least one revolution of the display member, and wherein the device further comprises a drive member for driving a non-rotating threaded piston rod, the drive member having a threaded surface for engaging the thread on the piston rod, the drive member being rotatable within the device but axially fixed and wherein a ratchet couples the dose setting member to the drive member so that the dose setting member is moveable in a first direction to set a dose, the first direction being against the bias of the torsion spring, and being moveable in a second direction with the bias of the spring in order to reset or reduce a set dose without rotating the drive member, and wherein the ratchet retains the dose setting member from rotating under influence of the spring and wherein upon release of a latch the spring drives the drive member to rotate, thereby axially advancing the piston rod, and wherein rotation of the drive member is accompanied by rotation of the dose display member which returns to a zero position upon completion of the ejection of the dose.
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Accused Products
Abstract
The present invention relates to an injection device comprising a torsion spring operatively connected to a dose setting member being adapted to set a dose to be ejected from the injection device. A rotatably mounted display member adapted to display the dose to be ejected in accordance with a setting of the dose setting member is also provided. The rotatably mounted display member is adapted to be rotated over an angle corresponding to at least one revolution of the display member. The display member may be implemented as a dose indicator barrel having numerals arranged along a helical path on an outer surface thereof, or alternatively, as a counting device having two or more display wheels having numerals arranged on an outer surface thereof.
108 Citations
30 Claims
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1. An injection device comprising
a helical torsion spring (12) operatively connected to a dose setting member (1), the dose setting member (1) being adapted to set a dose to be ejected from the injection device, and a rotatably mounted display member adapted to display the dose to be ejected from the injection device in accordance with a setting of the dose setting member (1), the rotatably mounted display member being rotatable over an angle corresponding to at least one revolution of the display member, and wherein the device further comprises a drive member for driving a non-rotating threaded piston rod, the drive member having a threaded surface for engaging the thread on the piston rod, the drive member being rotatable within the device but axially fixed and wherein a ratchet couples the dose setting member to the drive member so that the dose setting member is moveable in a first direction to set a dose, the first direction being against the bias of the torsion spring, and being moveable in a second direction with the bias of the spring in order to reset or reduce a set dose without rotating the drive member, and wherein the ratchet retains the dose setting member from rotating under influence of the spring and wherein upon release of a latch the spring drives the drive member to rotate, thereby axially advancing the piston rod, and wherein rotation of the drive member is accompanied by rotation of the dose display member which returns to a zero position upon completion of the ejection of the dose.
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16. A dose setting and injecting apparatus for assisting in the setting and ejection of a dose of medication from an injection device;
- the apparatus comprising
a. a housing component; b. a dose setting member capable of being rotated over an angle larger than 360 degrees; c. a dose indicator barrel having a helical display of numerals arranged thereon and that rotates back to an initial position during ejection of a dose of medication and that moves axially during rotation; d. a piston rod (2) having a threaded surface, the piston rod being non-rotatable relative to the housing; e. a drive member (6) having an internal thread that engages a portion of the threaded surface on the piston rod, the drive member being rotatable relative to the housing so that when it rotates it causes axial translation of the piston rod; f. a releasable locking member (4) that rotatably locks in a releasable manner the driver member so that it does not rotate relative to the housing component; g. a helical torsional spring which extends coaxially with the piston rod and which interconnects with the dose setting member in such a way that rotation of the dose setting member in a direction that sets a dose strains the spring; h. a ratchet coupling the dose setting member to the drive member, the ratchet allowing a dose to be set by a procedure that consists of dialing up a dose against the strain of the spring to set a dose size and, when necessary, dialing the dose setting member in an opposite direction to reduce the size of the dose, wherein the ratchet allows the dose setting member to be dialed in an up and a down direction without rotation of the drive member but where the ratchet prevents the torsional spring from rotating the dose setting member in a downward, dose reducing direction; wherein when the releasable locking member is released, the drive member is free to rotate under the influence of the spring and thereby drives the piston rod in an axial direction to expel a drug from the device. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
- the apparatus comprising
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28. A dose setting and injecting mechanism for an injection device, the mechanism comprising:
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a rotatable dose setting member being rotatable over more than one revolution; a dose indicator barrel that has a helical scale of numerals disposed thereon, the dose indicator barrel translating axially when rotated; a threaded non-rotating piston rod, the piston rod being driveable in a distal direction to expel a dose of medication; a rotatable but axially fixed drive member containing a thread that engages the thread on the piston rod; a torsional spring for storing energy needed to expel a dose of medication, the torsional spring being helical, the torsional spring being operable connected to the dose setting member so that when a dose is dialed up energy for ejecting medication is stored in the spring; a ratchet mechanism coupling the dose setting member with the drive member and allowing the dose setting member to be rotated over more than one revolution in a dose setting direction and to be rotated in a dose reducing direction without rotating the drive member, wherein the ratchet mechanism provides sufficient force to prevent the dose setting member from counter rotating under the influence of a force from the torsional spring; a releasable lock that prevents rotation of the drive member until it is released, thereby allowing the torsional spring to remain strained until it is released when performing an ejection; and wherein upon release of the lock, energy from the spring drives the drive member to rotate which drives the piston rod in a distal direction and simultaneously the dose indicator barrel is rotated to an initial position so that upon completion of the expulsion of the dose another dose can immediately be set and ejected.
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29. An injection device comprising:
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a rotatable dose setting member being rotatable over more than one revolution; a dose indicator barrel that has a helical scale of numerals disposed thereon, the dose indicator barrel translating axially when rotated; a threaded non-rotating piston rod, the piston rod being driveable in a distal direction to expel a dose of medication; a rotatable but axially fixed drive member containing a thread that engages the thread on the piston rod; a torsional spring for storing energy needed to expel a dose of medication, the torsional spring being helical, the torsional spring being operable connected to the dose setting member so that when a dose is dialed up energy for ejecting medication is stored in the spring; a coupling mechanism connecting the dose setting member with the drive member and allowing the dose setting member to be rotated over more than one revolution in a dose setting direction and to be rotated in a dose reducing direction without rotation of the drive member, wherein the coupling mechanism provides sufficient force to prevent the dose setting member from counter rotating under the influence of a force from the torsional spring; a releasable lock that prevents rotation of the drive member until it is released; and wherein upon release of the lock, energy from the spring drives the drive member to rotate which drives the piston rod in a distal direction and simultaneously the dose indicator barrel is rotated toward an initial position so that upon completion of the expulsion of the dose another dose can immediately be set and injected; and wherein the torsional spring operates over a substantially linear working range. - View Dependent Claims (30)
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Specification