Device for controlled dispensing of a dose of a liquid contained in a cartridge

• US 6,003,736 A
• Filed: 06/02/1998
• Issued: 12/21/1999
• Est. Priority Date: 06/09/1997
• Status: Expired due to Fees

• Current Assignee: Novo Nordisk A/S
• Original Assignee: Novo Nordisk A/S
• Inventors: Ljunggren, Henrik
• Primary Examiner(s): Kaufman, Joseph A.
• Application Number:
  US09/088,742
• Time in Patent Office: 567 Days
• Field of Search: 222/309, 222/333, 222/386, 222/389
• US Class Current: 222/309
• CPC Class Codes: A61M 2005/3152 including gearings to multiply or attenuate the piston displacing force
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/14566 with a replaceable reservoir for receiving a piston rod of the pump
• CPC Class Codes: A61M 5/20 Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically A61M5/142 , A61M5/46 take precedence; hypodermic projectiles F42B12/54
• CPC Class Codes: A61M 5/31525 Dosing burettes, pipettes B01L3/02
• CPC Class Codes: A61M 5/31541 Means preventing setting of a dose beyond the amount remaining in the cartridge
• CPC Class Codes: A61M 5/31546 Electrically operated dose setting, e.g. input via touch screen or plus/minus buttons
• CPC Class Codes: A61M 5/31558 using scaling up or down transmissions, e.g. gearbox
• CPC Class Codes: A61M 5/31561 using freely adjustable volume steps
• CPC Class Codes: A61M 5/31575 using scaling up or down transmissions, e.g. gearbox
• CPC Class Codes: A61M 5/31585 performed by axially moving actuator, e.g. an injection button
• CPC Class Codes: A61M 5/31593 Multi-dose, i.e. individually set dose repeatedly administered from the same medicament reservoir

Abstract

The present invention relates to an improved displacement device (1) for controlled dispensing of a dose of a liquid contained in a cartridge (40), the displacement device (1) comprises a housing (5) incorporating: a mechanism (6) for accommodating the cartridge (40), a manually activatable displaceable elongated dose dispensing device (20), the elongated dose dispensing device (20) having a first end part (22) extending to the exterior of the housing (5), an elongated piston rod (30) connected with a displaceable piston (32), the piston (32) being adapted to press out the liquid contained in the cartridge (40), and the piston rod (30) having a plurality of transversely extending teeth (25) arranged along its length, a toothed displacing mechanism (14), and a user-operated dose setting mechanism (8,10,12), the user-operated dose setting mechanism (8,10,12) and the toothed displacing mechanism (14) are operatively connected to cause movement of the toothed displacing mechanism (14) in response to the operation of the dose setting mechanism (8,10,12), pinion mechanism (35) having a shaft (37), being rotatably secured to the elongated dose dispensing device (20), the pinion mechanism (35) being arranged to engage the teeth of the toothed displacing mechanism (14) and the teeth (25) of the piston rod (30).

Claims

1. A displacement device (1) for controlled dispensing of a dose of a liquid contained in a cartridge (40), said displacement device (1) comprising a housing (5) incorporating:

a means (6) for accommodating said cartridge (40),

a manually activatable displaceable elongated dose dispensing means (20),

said elongated dose dispensing means (20) having a first end part (22) extending to the exterior of the housing (5),

an elongated piston rod (30) connected with a displaceable piston (32),

said piston (32) being adapted to press out the liquid contained in said cartridge (40), and

said elongated piston rod (30) having a plurality of transversely extending teeth (25) arranged along its length,

a toothed displacing means (14),

a user-operated dose setting means (8,10,12),

said user-operated dose setting means (8,10,12) and said toothed displacing means (14) being operatively connected to cause movement of said toothed displacing means (14) in response to the operation of the dose setting means (8,10,12),

pinion means (35) having a shaft (37),

said pinion means (35) being rotatably secured to said elongated dose dispensing means (20),

said pinion means (35) being arranged to engage the teeth of said toothed displacing means (14) and the teeth (25) of the piston rod (30).

2. A displacement device according to claim 1, characterized in that

the toothed displacing means (14) is formed as a screw means having a helical thread, said screw means being caused to rotate about its longitudinal axis in response to the operation of the dose setting means (8,10,12).

3. A displacement device according to claim 1, characterized in that

the toothed displacing means (14) is formed as a displaceable endless toothed rack, means being provided for permitting said toothed rack to be held immovably during dispensing of a dose of liquid.

4. A displacement device according to claim 1, characterized in that

the piston rod (30) is formed as a flexible member.

5. A displacement device according to claim 1, characterized in that

said housing (5) comprises guiding surfaces (7,9) for supporting the dose dispensing means (20), one of said guiding surfaces being preferably formed by an opening (7) in said housing and engaging said first end part (22) of the elongated dose dispensing means (20).

6. A displacement device according to claim 5, characterized in that

said housing (5) comprises a guiding surface (9,9'"'"',9") adapted to control the displacement of said dose dispensing means (20).

7. A displacement device according to claim 6, characterized in that

said guiding surface (9,9'"'"',9") engages said shaft (37) of the pinion means (35),

said guiding surface (9.9'"'"',9") is formed by an elongated track extending in parallel with the elongated dose dispensing means (20), and has first and second end surfaces (9'"'"',9") adapted to limit the displacement of said dose dispensing means (20).

8. A displacement device according to claim 1, characterized in that

said pinion means (35) is provided with a first and a second set of teeth, the first set of teeth engaging the teeth of said toothed displacing means (14) and the second set of teeth engaging the teeth (25) of the piston rod (30).

9. A displacement device according to claim 1, characterized in that

said user-operated dose setting means comprises a motor (12) and a motor control means (8) having a dose selecting means (10).

10. A displacement device according to claim 1, characterized in that

said first end part (22) of said displaceable elongated dose dispensing means (20) is provided with user-inspectable markings (21) indicating the set dose.