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US 6,883,552 B2Granted
Metal tube and its production method
AssigneesTerumo Kabushiki Kaisha, Okano Kogyo Co., Ltd.
InventorsTetsuya Ooyauchi, Masayuki Okano
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AssigneesTerumo Kabushiki Kaisha, Okano Kogyo Co., Ltd.
InventorsTetsuya Ooyauchi, Masayuki Okano
Estimating the term…
A small diameter metal tube having at least two inner diameters is provided. A method for producing this metal tube is also provided. In this method, a plate member having a development shape of the metal tube is blanked from a metal thin plate so that the plate member is left partly tied to the metal thin plate, the plate member is press formed into a tubular body having the at least two inner diameters, and the plate member partly tied to the metal thin plate is cut apart to produce the metal tube having at least two inner diameters.
A metal tube produced by press forming, which has at least two inner diameters, wherein the inner surface of the tube has a maximum height difference (RF) in the surface roughness of up to 3 μm after press forming, and the tube has a minimum inner diameter of up to 2 mm and a maximum inner diameter of up to 5 mm.
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
Manufacture of metal sheets, rods, wire, tubes, profiles or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of…:…
Of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes: making tubes with welded or soldered seams
Making tubes with welded or soldered seams: without continuous longitudinal movement of the sheet during the bending operation
Making tubes with welded or soldered seams: supply, or operations combined with supply, of strip material
Term ended 31 Dec 2022 (estimated)
1. Field of the Invention
This invention relates to a metal tube of irregular shape which has at least two inner diameters, and its production method. To be more specific, this invention relates to a small diameter, irregular shaped metal tube which can be used for a pin, injection needle, connector, electron gun for TV liquid crystal, and the like, and its production method.
2. Prior Art
FIGS. 1A, 1B and 1C are front, side and back views of tubes according to some embodiments of the present invention.
FIGS. 2A to 2E are front, side and back views of tubes according to other embodiments of the present invention.
FIGS. 3A and 3B schematically show the tube production according to the method of the invention, FIG. 3A being a view when a plate member having a development shape of a tube has been blanked from a metal thin plate; and FIG. 3B being a view when the plate member has been curled by press forming.
Next, the method for producing the metal tube of the present invention as well as the metal tube produced by such method are described with reference to the preferred embodiments shown in the accompanying drawings.
The metal tube of the present invention is characterized by its irregular shape having at least two inner diameters. Typical such tubes include a hollow tube 8 having a circular cross section as shown in FIG. 1A which is tapered from the distal end having a smaller inner diameter to the proximal end having a larger inner diameter; a hollow tube 8 of circular cross section as shown in FIG. 1B having a stepped side profile which comprises a distal portion having a small inner diameter, a proximal portion having a large inner diameter, and an intermediate portion between the distal and proximal portions which is different in the inner diameter from the distal and proximal portions; and a hollow tube 8 of circular cross section as shown in FIG. 1C comprising a distal portion having a small inner diameter, a proximal portion having a large inner diameter, and a transient portion between the distal and proximal portions. In FIGS. 1A to 1C, reference numeral 9 represents the central axis of the tube 8. Further examples of the tube according to the present invention are shown in FIGS. 2A to 2E. FIG. 2A shows a hollow tube of quadrilateral cross section which comprises a distal portion having a small inner diameter, a proximal portion having a large inner diameter, and a transient portion between the distal and proximal portions. FIG. 2B shows a hollow tube which comprises a distal portion having a small inner diameter, a proximal portion having a large inner diameter, and a transient portion between the distal and proximal portions, and in which the distal portion has a circular cross section whereas the proximal portion has a quadrilateral cross section. FIG. 2C shows a hollow tube of circular cross section which comprises a distal portion having a small inner diameter, a proximal portion having a large inner diameter, and a transient portion between the distal and proximal portions. FIG. 2D shows a hollow tube of hexagonal cross section comprising a distal portion having a small inner diameter, a proximal portion having a large inner diameter, and a transient portion between the distal and proximal portions. FIG. 2E shows a hollow tube of circular cross section comprising a distal portion having a small inner diameter, a proximal portion having a large inner diameter, two first and second intermediate portions formed between the distal and proximal portions and having inner diameters which are different from each other and which are also different from those of the distal and proximal portions, and transient portions formed between the distal portion and the first intermediate portion, between the first and second intermediate portions, and between the second intermediate portion and the proximal portion.
Typical application of such metal tube having at least two inner diameters is an injection needle used in epidural injection. In the case of inserting the injection needle for use in epidural injection, the tapered or stepped profile of the needle functions as a sensor or indicator for the location of the needle tip, thereby preventing nerve and other fine tissues from being damaged by the needle which had gone too far.