Solenoid drive apparatus for an external infusion pump

[54] SOLENOID DRIVE APPARATUS FOR AN EXTERNAL INFUSION PUMP

[75] Inventors: Clyde K. Nason, Valencia; Gordon W.

Culp, Van Nuys, both of Calif.

[73] Assignee: Pacesetter Infusion, Ltd., Sylmar,
Calif.

[21] Appl. No.: 779,733
[22] Filed: Sep. 24, 1985

Related U.S. Application Data

[63] Continuation of Ser. No. 568,615, Jan. 6, 1984.

[51] Int. CI." F04B 9/06; F04B 13/00

[52] U.S. a 417/410; 74/128;

74/142

[58] Field of Search 417/22, 410; 74/126,

74/128, 142

[56] References Cited

U.S. PATENT DOCUMENTS

3,115,589 12/1963 Bender et al 74/142 X

3,204,133 8/1965 Tschudin 74/142

3,341,138 9/1967 Allen 74/142 X

3,501,968 3/1970 Fredell 74/128

3,618,868 11/1971 Vavrinec 74/128 X

4,474,309 10/1984 Solomon 417/22 X

4,562,751 1/1986 Nason et al 74/111

Primary Examiner—Carlton R. Croyle

Assistant Examiner—Ted Olds

Attorney, Agent, or Firm—Leslie S. Miller; Bryant R.

Gold

[57] 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).

11 Claims, 14 Drawing Figures