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US 5,636,064 AGranted
Zoom lens barrel with flat faced helicoid threading
AssigneeAsahi Kogaku Kogyo Kabushiki Kaisha
InventorsHiroshi Nomura, Takamitsu Sasaki
Life of this patent
Estimating the term…
Abstract
An end surface of external helicoid threads provided on an inner movable barrel and an end surface of a ring member attached to an outer barrel having internal helicoid threads are arranged to be parallel, in order that the ring member does not undergo detaching forces. The ring member is thereby able to resist detachment if the inner barrel is overextended.
Claims17
A zoom lens barrel comprising:
- an outer barrel, an object side of said outer barrel defined as a side facing an object to be photographed;
- internal helicoid threading arranged on an inner surface of said outer barrel;
- an inner barrel, said inner and outer barrels being concentric about an axis;
- external helicoid threading arranged on an outer surface of said inner barrel, said external helicoid threading having a flat end face on an object side end, and said internal helicoid threading and said external helicoid threading being engaged to drive said inner barrel in a direction of said axis;
- and
- a flat-faced ring member attached within an object side end of said inner surface of said outer barrel, and having an inner flat face parallel to said flat end face on said object side end of said external helicoid threading.
3 more elements
A zoom lens barrel comprising:
- an outer barrel, an object side of said outer barrel defined as a side facing an object to be photographed;
- internal helicoid threading arranged on an inner surface of said outer barrel;
- an inner barrel, said inner and outer barrels being concentric about an axis;
- external helicoid threading arranged on an outer surface of said inner barrel, said external helicoid threading having a flat end face on an object side end, said internal helicoid threading and said external helicoid threading being engaged to drive said inner barrel in a direction of said axis;
- a flat-faced ring member attached within an object side end of said inner surface of said outer barrel, and having an inner flat face parallel to said flat end face on said object side end of said external helicoid threading;
- said inner flat face of said flat-faced ring member and said flat end face on said object side end of said external helicoid threading being flush when in contact;
- said flat end face on said object side end of said helicoid threading being perpendicular to said axis;
- and
- said inner flat face of said flat-faced ring member being perpendicular to said axis,
- wherein all contact forces between said inner flat face and said flat end face are in said direction of said axis.
7 more elements
A zoom lens barrel comprising:
- an outer barrel, an object side of said outer barrel defined as a side facing an object to be photographed, internal helicoid threading provided on an inner surface of said outer barrel;
- an inner barrel, said inner and outer barrels being concentric about an axis;
- external helicoid threading provided on an outer surface of said inner barrel, said external helicoid threading having a flat end face on an object side end, said internal helicoid threading and said external helicoid threading being engaged to drive said inner barrel along a direction of said axis;
- and
- a flat-faced ring member attached at an object side to said outer barrel, said flat-faced ring member having an inner diameter smaller than an inner diameter of said outer barrel and larger than an outer diameter of said inner barrel, said flat-faced ring member having an inner surface facing inwardly towards said internal helicoid threading and said external helicoid threading, said inner surface being parallel to said flat end face on said object side end of said external helicoid threading.
2 more elements
Dependencies are inferred from the claim text.