Solenoid drive apparatus for an external infusion pump

• US 4,562,751 A
• Filed: 01/06/1984
• Issued: 01/07/1986
• Est. Priority Date: 01/06/1984
• Status: Expired due to Term

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Culp, Gordon W., Nason, Clyde K.
• Primary Examiner(s): Yuen, Henry C.
• Application Number:
  US06/568,615
• Time in Patent Office: 732 Days
• Field of Search: 74/111, 74/128
• US Class Current: 74/111
• CPC Class Codes: A61M 5/1456 with a replaceable reservoir comprising a piston rod to be moved into the reservoir, e.g. the piston rod is part of the removable reservoir
• CPC Class Codes: A61M 5/1458 Means for capture of the plunger flange
• CPC Class Codes: Y10T 74/15 Intermittent grip type mechanical movement
• CPC Class Codes: Y10T 74/1529 Slide actuator

Abstract

A solenoid drive apparatus for driving a lead screw of an External Infusion Pump (1) having a housing (302), solenoid winding (356) within the housing (302), a solenoid armature (358) which is driven by the field of the solenoid winding (356), push rod (362) which is driven by the armature (358), pawn (314) which is driven by push rod (362), a first pawl (320) which is driven by pawn (314) and a second pawl (326) which is an antibacklash device, a ratchet wheel (318) having teeth (319) around its periphery and engaged by the first pawl (320) and the second pawl (326) and the drive shaft (316) which is drawn by the ratchet of the ratchet wheel (318).

Claims

1. A drive apparatus comprising:

a housing;

solenoid electrical means within said housing for controlling a mechanical output of said drive apparatus;

drive transmission means within said housing responsive to said solenoid electrical means, said drive transmission means including an actuator member and a follower member that linearly move in a first linear direction in response to electrical energy applied to said solenoid electrical means;

driver means within said housing responsive to said drive transmission means, said driver means translating the motion in the first linear direction to motion in a second linear direction;

shaft means disposed through a portion of said housing;

ratchet means disposed at a first end of said shaft means;

ratchet drive means slidably attached to said housing having a first portion connected to said driver means and having a second portion engaging said ratchet means, the first portion of said ratchet drive means being driven with a first force by said driver means in said second linear direction by the response of said solenoid electrical means, thereby causing said ratchet means to rotate, thereby turning said shaft means;

stop means rotatably attached to said housing and having at least one portion engaging said ratchet means;

first biasing means for biasing said ratchet drive means into engagement with said ratchet means with a second force that is less than said first force; and

second biasing means for biasing said portion of the stop means into engagement with said ratchet means;

wherein after said ratchet drive means has been displaced a maximum amount, and after said solenoid electrical means has ceased to drive said ratchet drive means to its maximum displaced position, said first biasing means, in the absence of said first force, causes said ratchet drive means, driver means, follow member and actuator means to assume a position each means and member had prior to being displaced by said solenoid electrical means.

2. The apparatus as recited in claim 1 wherein said follower member includes a push rod.

3. The apparatus as recited in claim 1 wherein said driver means includes a pawl shaped member.

4. The apparatus as recited in claim 1 wherein said ratchet means includes a ratchet wheel having teeth disposed around a circumference of said wheel.

5. The apparatus as recited in claim 4 wherein said ratchet drive means includes a pawl having a tip portion for engaging the teeth of said ratchet wheel.

6. The apparatus as recited in claim 4 wherein said stop means includes a member having a tip for engaging the teeth of said ratchet wheel, said tip preventing rotation of said ratchet wheel in a direction opposite the one said ratchet wheel is driven.

7. The apparatus as recited in claim 1 wherein said first and second biasing means comprise springs.

8. The apparatus as recited in claim 1 wherein the first linear direction in which said actuator member and follower member linearly move is parallel to a longitudinal axis of said shaft means.