JPH08309671A - Clamping fixture - Google Patents

Abstract

PURPOSE: To prevent bending of a tip end, meshing inferiority, or the like. by forming a part in contact with a clamped unit with a super elastic alloy. CONSTITUTION: A total length of a pair of super elastic alloy-made tweezers 1 is about 85mm, to form a tooth of height about 10mm in an opening part about 0.3mm with about 1mm × about 1mm in a tip end part 2. A restorable strain amount of this super elastic alloy leads to even about 8%, to largely exceed a value such as about 1% or less a restorable strain amount of an ordinary metal of stainless steel or the like. Accordingly, by using a super elastic alloy in a part at least into contact with a clamped unit, inferiority of bending a tip end, worsening meshing, etc., is prevented from being generated. This super elastic alloy is composed of Ni: 49 to 52at% and the rest part Ti and inevitable impurities, or with a composition substituting one kind or two kinds or more elements of Fe, Cr, Al, V, Pd, Mn, Co, Nb, Cu for partly Ni or Ti, to set ratio of this substitution element to within a 0.01 to 2at.% range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gripping tool made of a superelastic alloy, and a gripping tool for gripping an object to be gripped in an assembly process, a moving process, etc. in various industrial automated production lines, and especially for medical use. The present invention relates to tweezers and the like used when precision work is required for precision equipment assembly work, chemical experiments, etc., for example, when used in ophthalmic surgery or when carrying out etching treatment while holding a semiconductor wafer or the like. Is used.

[0002]

2. Description of the Related Art It has been conventionally known that NiTi alloys have shape memory characteristics and superelastic characteristics due to thermoelastic martensitic transformation. Among them, the superelastic property is a property that even if a deformation strain of 6 to 8% is applied when a load is applied, the shape returns to the original shape when the load is removed. Orthodontic wire,
Bra wires, eyeglass frames, medical guide wires, etc.

With regard to the grasping tool, particularly when a fine work is required at the time of surgery or the like, it is necessary to perform a fine work through an incision as small as possible. Therefore, the tip of the tweezers used for this is particularly fine and precise. For example, surgical tweezers have teeth on the tip for grasping tissue, or have a flat tip for suturing with a thread. There are various shapes in total, and it is an essential condition that the tip of each shape has good meshing in any shape.

Various materials are used as the material for the gripping tool according to the intended use. However, most of the surgical tweezers have hitherto been used because of their corrosion resistance and ease of disinfection. Things are made of stainless steel. Also,
Some of them are made of titanium with further improved corrosion resistance and durability.

[0005]

However, as described above, since the tip of surgical tweezers is particularly finely and precisely manufactured, if the tip is made of stainless steel or titanium, the tip tends to be bent and the engagement tends to deteriorate. There was a problem. In addition, stainless steel or titanium tweezers have a small amount of recoverable strain of about 1%, so if you handle them roughly violently, you will not be able to use them once, and even if you handle them carefully, they can be used dozens of times. Engaging the tips of the grips makes them unusable, requiring repair each time, or in the worst case, discarding them. Therefore, extending the life of the gripping tools such as tweezers has been a major issue.

[0006]

As a result of various studies in view of this, the present invention has solved the above problems and improved durability.
It is an invention of a gripping tool having a long life.

That is, the first aspect of the present invention is a gripping tool characterized in that a portion contacting the object to be gripped is made of a superelastic alloy.

According to a second aspect of the present invention, the superelastic alloy comprises Ni: 49 to 52 at%, the balance Ti and inevitable impurities, or a part of the Ni or Ti is F.
e, Cr, Al, V, Pd, Mn, Co, Nb, and Cu, which are substituted with one or more elements,
The gripping tool according to claim 1, wherein the ratio of the substituting element is within a range of 0.01 to 2 at%.

[0009]

The present invention takes advantage of the property that even if the superelastic alloy is deformed by an external force, it can be completely restored to its original shape immediately after unloading. The recoverable strain amount of the superelastic alloy reaches as high as 8%, which greatly exceeds the recoverable strain amount of 1% or less for ordinary metals such as stainless steel. Therefore, by using the superelastic alloy at least in the portion that comes into contact with the object to be grasped, problems such as bending of the tip and bad engagement are prevented. In other words, in the present invention, the effect can be sufficiently obtained if the superelastic alloy is used only in the portion of the gripping tool that comes into contact with the object to be gripped, and the entire gripping tool may be manufactured from the superelastic alloy.

In the second aspect of the invention, the superelastic alloy is composed of Ni: 49 to 52 at% and the balance is Ti, or a part of the Ni or Ti is Fe or C.
1 of r, Al, V, Pd, Mn, Co, Nb, Cu
The reason is that the composition is a composition in which one kind or two or more kinds of elements are substituted, and the ratio of the substituting element is in the range of 0.01 to 2 at%. %, The workability and corrosion resistance are good, and when used at the time of surgery, etc., the biocompatibility peculiar to the NiTi alloy is excellent.

The gripping tool of the present invention is suitable for a case where a fine work such as an operation is required, but the ophthalmic surgery requires a particularly fine work as compared with a normal surgery. It is an operation and is the field of application in which the grasping tool of the present invention is most effective. Needless to say, the life of the gripping tool can be extended by using the gripping tool of the present invention even when particularly fine work is not required.

[0012]

EXAMPLE An example of the present invention will be described below with reference to FIG.

FIG. 1 shows a gripping tool of the present invention. In the examples, superelastic alloy tweezers (1) were used, the total length thereof was 85 mm, the opening portion was 10 mm, the tip portion (2) was 1 mm × 1 mm, and the height was 0.3 mm as shown in FIG. Teeth (5) are formed. Three types of tweezers having the same shape and size shown in FIG. Ni: 50.6 at%, Fe: 0.2 at%, balance T
A tweezers entirely constituted by a superelastic alloy having a composition of i and inevitable impurities (example of the present invention). Ni: 50.85 at%, the tip portion is made of a superelastic alloy having a composition of the balance Ti and unavoidable impurities, and the grip portion is tweezers made of stainless steel (Example of the present invention: FIG. 2). Tweezers made entirely of stainless steel (conventional example). These tweezers were used for eye surgery. Surgery involves removing the clouded lens and inserting an artificial lens.Comparing how many times the tweezers do not match the tips of the tweezers and hinder the use during surgery and necessary cleaning and disinfection. did. For both tweezers,
It was done by an experienced doctor who carefully operated on the surgery and did not drop or hit it.

Both of them were used in groups of three. Table 1 shows the results.

[0015]

[Table 1]

The conventional stainless steel tweezers of
As shown in Table 1, after a few dozen times, there was a problem in use,
In contrast to the need for repair, the tweezers made of the superelastic alloy of the present invention causes no trouble even if it is used 100 times or more,
Significantly longer life than conventional tweezers.

Experiments were also conducted assuming that the handling was rough. Each of the tweezers was dropped onto a stainless steel tray from a height of 10 cm. As a result, none of the tweezers was deformed, whereas the tip of the tweezers was bent and could not be used. As described above, it was found that the superelastic alloy tweezers of the present invention cause no problem even if they are handled roughly.

[0018]

As described in detail above, the gripping tool characterized in that at least the portion of the gripping tool that comes into contact with the object to be gripped is made of a superelastic alloy, as compared with conventional gripping tools made of stainless steel. , The bending of the tip, the problem of engagement, etc. are prevented, and the effect of achieving a significantly long life is achieved.

[Brief description of drawings]

FIG. 1 is an overall view of a superelastic alloy tweezers according to an embodiment of the present invention.

FIG. 2 is an overall view of superelastic alloy tweezers according to another embodiment of the present invention.

FIG. 3 is an enlarged view of a tip portion of a superelastic alloy tweezers according to an embodiment of the present invention.

[Description of sign]

 1 Super elastic alloy tweezers 2 Tip 3 Super elastic alloy 4 Stainless steel 5 Teeth

Claims (2)

[Claims] 1. A gripping tool, characterized in that a portion in contact with the object to be gripped is made of a superelastic alloy. 2. A superelastic alloy comprising Ni: 49 to 52 at%, the balance Ti and unavoidable impurities, or the above N.
Part of i or Ti is Fe, Cr, Al, V, Pd, M
A composition in which one or more elements of n, Co, Nb, and Cu are substituted, and the ratio of the substitution elements is 0.01.
The gripping tool according to claim 1, wherein the gripping tool is in the range of 2 at%.