Injection molded threaded rotor and manufacture method

• US 6,774,517 B2
• Filed: 07/24/2002
• Issued: 08/10/2004
• Est. Priority Date: 02/01/2000
• Status: Expired due to Term

• Current Assignee: Tritex Corp. (Ametek Incorporated)
• Original Assignee: Tritex Corp. (Ametek Incorporated)
• Inventors: Kowalski, Keith, Maini, Nino
• Primary Examiner(s): Lam, Thanh
• Assistant Examiner(s): JONES, JUDSON
• Application Number:
  US10/182,012
• Publication Number:
  US 20030001443A1
• Time in Patent Office: 748 Days
• Field of Search: 310/12, 310/13, 310/14, 310/20, 310/80, 318/135, 295/98
• US Class Current: 310/80
• CPC Class Codes: B29C 45/14344 Moulding in or through a hole in the article, e.g. outsert moulding
• CPC Class Codes: B29C 45/2618 having screw-threaded mould walls
• CPC Class Codes: H02K 7/06 Means for converting reciprocating motion into rotary motion or vice versa
• CPC Class Codes: Y10T 29/49009 Dynamoelectric machine

Abstract

In a preferred embodiment, a threaded rotor for a linear actuator, including: a generally cylindrical, metallic shell/insert (20); and a generally cylindrical threaded thermoplastic member (72) disposed in a wall of the generally cylindrical shell/insert, the threaded thermoplastic member having threads formed on an inner surface thereof and engagable with complementary threads formed on an outer surface of a shaft to be inserted in the generally cylindrical shell/insert.

Claims

1. A threaded rotor for a linear actuator, comprising:

(a) a generally cylindrical, metallic shell/insert having two bearing areas on an external surface thereof; and

(b) a generally cylindrical threaded thermoplastic member fixedly disposed in a wall of said generally cylindrical, metallic shell/insert, said threaded thermoplastic member having threads formed on an inner surface thereof and engagable with complementary threads formed on an outer surface of a shaft to be inserted in said generally cylindrical, metallic shell/insert.

2. A threaded rotor for a linear actuator, as defined in claim 1, further comprising:

at least one slot formed in said wall of said generally cylindrical, metallic shell/insert into which a portion of said threaded thermoplastic member extends outwardly to prevent relative axial and radial movement of said threaded thermoplastic member in said generally cylindrical, metallic shell/insert.

3. A method of manufacture of a threaded rotor for a linear actuator, comprising:

(a) machining a generally cylindrical shell/insert having two bearing areas;

(b) placing said generally cylindrical shell/insert in a mold; and

(c) injecting a thermoplastic material into said mold such as to form a threaded thermoplastic member disposed in a wall of said shell/insert, said threaded thermoplastic member having threads formed on an inner surface thereof and engagable with complementary threads formed on an outer surface of a shaft to be inserted in said generally cylindrical shell/insert.

4. A method of manufacture of a threaded rotor for a linear actuator, as defined in claim 3, wherein:

said step of injecting includes injecting said thermoplastic material into at least one slot formed in said generally cylindrical shell/insert to permit some of said thermoplastic material to extend outwardly therein to prevent rotation of said threaded thermoplastic member in said shell/insert.

5. A method of manufacture of a threaded rotor for a linear actuator, as defined in claim 4, further comprising the step of inserting into said generally cylindrical shell/insert, before insertion of said shell/insert into said mold, a locking core pin and a threaded locking core pin, a thread on said threaded locking core pin forming a thread on said threaded thermoplastic material when said thermoplastic material is injected into said mold.

6. A method of manufacture of a threaded rotor for a linear actuator, comprising:

(a) machining a generally cylindrical shell/insert having two bearing areas;

(b) placing said generally cylindrical shell/insert in a mold;

(c) injecting a thermoplastic material into said mold such as to form a threaded thermoplastic member disposed in a wall of said shell/insert, said threaded thermoplastic member having threads formed on an inner surface thereof and engagable with complementary threads formed on an outer surface of a shaft to be inserted in said generally cylindrical shell/insert, and injecting said thermoplastic material into at least one slot formed in said generally cylindrical shell/insert to permit some of said thermoplastic material to extend outwardly therein to prevent rotation of said threaded thermoplastic member in said shell/insert; and

(d) inserting into said generally cylindrical shell/insert, before insertion of said shell/insert into said mold, a locking core pin and a threaded locking core pin, a thread on said threaded locking core pin forming a thread on said threaded thermoplastic material when said thermoplastic material is injected into said mold.