Helically threaded mechanism

• US 4,582,350 A
• Filed: 10/10/1984
• Issued: 04/15/1986
• Est. Priority Date: 10/13/1983
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Okajima, Hidekazu
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): BEN, LOHA
• Application Number:
  US06/659,338
• Time in Patent Office: 552 Days
• Field of Search: 350/429, 350/255, 285/390, 285/391, 285/34, 285/35
• US Class Current: 285/390
• CPC Class Codes: G02B 7/04 with mechanism for focusing or varying magnification

Abstract

A helicoid thread mechanism which comprises a male helically threaded tube and a female helically threaded tube is provided with a helically threaded block for threadedly engaging the female tube onto the male tube. A sliding frictional contact noise which is produced between the two tube members when they engage with each other is eliminated by suitable selection on the helically threaded shape and the material of the block.

Claims

1. A helicoid mechanism comprising:

male and female helically threaded tubes;

a plurality of stowing parts such as recesses or openings formed in the outer circumference of said male tube;

block pieces provided with helically threaded parts for threaded engagement with said female tube and inserted in said stowing parts respectively; and

a tooth profile of the threaded portion of said male tube being shorter than that of the threaded parts of said block pieces.

2. A helicoid mechanism according to claim 1, wherein said male and female tubes are made of a plastic material containing glass fiber;

while said block pieces are made of a plastic material not containing glass fiber.

3. A helicoid mechanism according to claim 2, wherein said male and female tubes are made of a poly-carbonate resin material containing glass fiber;

and said block pieces are made of a poly-acetal resin material containing molybdenum disulfide.

4. A helicoid mechanism comprising:

male and female helically threaded tubes;

a plurality of stowing parts such as recesses or openings formed in the outer circumference of said male tube;

block pieces provided with helically threaded parts for threaded engagement with said female tube and inserted in said stowing parts respectively;

said block pieces and said stowing parts having said block pieces turnable for adjustment so as to eliminate rattling or play of the threaded engagement between said female tube and said block pieces by the turning movement of said block pieces.