JP2010005753A - Tweezers for holding calibration weight - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tweezers for holding a calibration weight which can lessen load on a fulcrum section at the time of holding a heavy weight and can apply sufficient force to a force-applied point section. <P>SOLUTION: The tweezers 10 is provided with the fulcrum section 12, in which two pieces of tabular metal plates are arranged so as to face each other and mutually joined and fixed at a base end side, a holding section 14 at a pointed head side, and a holding force generation section 16 between the fulcrum section 12 and the holding section 14. The fulcrum section 12 has a zone with the same width as that formed at the base end side of the metal plate, the holding force generation section 16 has a zone with the maximum width formed on an approximately central section of the metal plate, and the holding section 14 has a tapered zone formed at a pointed head side of the metal plate. The fulcrum section 12 is covered with a flexible support material 18 made of a synthetic resin and rubber, the holding force generation section 16 is covered with a slip-preventive gripping material 22 made of a synthetic resin and rubber, and the holding section 14 is covered with a thermal conduction-preventive cap 20 in order to maintaining frictional force with a calibration weight. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to tweezers for holding a calibration weight, and more particularly to tweezers suitable for holding a calibration weight having a wide range of weights.

  Since the balance and scale cannot directly measure the mass, it is necessary to perform gravity correction at each location where the balance or scale is installed or for each model. This gravity correction is based on the assumption that the weight acceleration is constant at the place where traceable weights are made based on the international standard 1kg prototype in France. X Gravity acceleration is applied as a force to the measuring instrument, and the mass sensor displacement generated by the force is converted by the electric force required to return to zero, and the mass of the object to be measured is determined (estimated). .

  For example, in Japan, mainly due to the difference in latitude, the maximum difference in gravitational acceleration is about 1/1000 (0.1%), and for measuring instruments where the difference between the weighing capacity and the minimum display amount is 1000 times or more Appears as a large weighing error.

  More specifically, in an analytical balance having a weighing capacity of 200 g × minimum display of 0.1 mg, even if the same 200 g sample is measured, the gravitational acceleration difference is 200 g × 1/1000 = 0.2 g, which is the minimum display. It is measured with an error of 2000 times. In addition to gravitational acceleration, changes in measured values occur due to changes in temperature, pressure, and humidity, so calibration with a weight is inevitable.

  The calibration of the weighing instrument with weights prevents contamination of the weights and does not damage them, does not transmit body temperature to the weights, does not cause thermal convection due to body temperature in the weighing chamber, does not carry magnetism or static electricity, and does not have magnetic or static electricity. There is a demand for reliable and easy operation, repetitive operation that does not make people tired, and safe and accurate operation without causing weight drop, etc. Absent.

  In particular, in the case of tweezers for calibration weight, a weight of about 200 g is often gripped, and a weight of 500 g to 1 kg at the maximum and 1 to 2 g at the minimum may be used.

The maximum weight in this range greatly exceeds the gripping weight assumed for ordinary tweezers on the market, and it is easily assumed that a dedicated design is required.
Conventional tweezers that have been used for gripping calibration weights use ordinary metal tweezers, and have a tweezers body made up of a structure (see Patent Document 1) in which a resin protector is placed on the tip gripping part. Dedicated structures are provided. However, such conventional tweezers have the following problems.

Japanese Utility Model Publication No. 53-8282

  In other words, normal tweezers are intended to grab a small object, whereas weight tweezers are intended to grasp heavy metal weights, and the usual tweezers operation is to hold one point with the thumb, index finger, and middle finger. Unlike tweezers used for gripping the weight of a component, functionally, when operating the weight, the part that grips the weight that acts as the action point, the force point that is pinched by the finger, and the little finger that is the fixed point when tweezers is operated A fulcrum part to be gripped with is required.

  However, in the former structure, the metal tweezers are thin due to the need for weight reduction, and there is a problem that the burden on the hand and little finger is increased at the fulcrum part, especially when a heavy weight is grasped. The structure was such that a sufficient force could be applied to the finger at the power point.

  In the latter structure, many of the tweezers made of resin are small, especially those for heavy weights, which require rigidity and are thick due to the production technical background of the injection molding and weight limitations. Since there is an upper limit and the thickness cannot be increased, the result is a rib structure for providing rigidity depending on the shape, and has a considerable volume. However, the large volume has a problem that the operability when performing fine work is poor, such as when holding a weight in the windshield of a balance / balance.

  The present invention has been made in view of such conventional problems. The object of the present invention is to reduce the burden on the fulcrum portion even when a heavy weight is gripped, and to provide sufficient force on the force point portion. It is possible to avoid deterioration of operability when performing fine work in the draft shield set on the balance and balance, and to reduce the heat conduction from the human body. Another object of the present invention is to provide tweezers for holding a calibration weight capable of blocking the metal part of the tweezers.

  In order to achieve the above-mentioned object, the present invention has a fulcrum part in which two flat metal plates are arranged facing each other and bonded and fixed to each other on the base end side, and the thickness of the fulcrum part is set to be different from that of other parts. And a gripping portion for the calibration weight that is vertically spaced apart on the tip side, and a gripping force generating portion is provided between the fulcrum portion and the gripping portion, and by applying force to the gripping force generating portion, The tweezers can move the flat metal plates close to each other and grip the calibration weight with the gripping portion, and the fulcrum portion is a region of the same width formed on the base end side of the metal plate The gripping force generating portion is a region having a maximum width formed at a substantially central portion of the metal plate, and the gripping portion is formed by a tapered region formed on the tip side of the metal plate, The fulcrum portion is covered with a flexible support material formed of synthetic resin or rubber, and the grip The force generation part is covered with a grip material for preventing slip formed of synthetic resin or rubber, and the grip part maintains a frictional force with the calibration weight and is covered with a cap for preventing heat conduction. did.

  According to the calibration weight grasping tweezers configured in this way, two flat metal plates are arranged facing each other and have a fulcrum part that is bonded and fixed to each other on the base end side, so that sufficient rigidity is secured. Also, since the fulcrum part is covered with a flexible support material made of synthetic resin or rubber, when the fulcrum part is grasped by the little finger and palm, the burden on the finger is alleviated and reliable. The function as a fulcrum can be demonstrated.

  In addition, the gripping force generation part is the maximum width area formed at the approximate center of the metal plate and is covered with a slip-preventing grip material made of synthetic resin or rubber. Can be applied.

  Furthermore, the gripping portion is formed of a tapered region formed on the front end side of the metal plate, maintains the frictional force with the calibration weight, and is covered with a cap for preventing heat conduction. Therefore, it is possible to reduce the measurement error due to the convection of air generated by heat in the weighing chamber formed by the windshield, and at the same time, avoid the deterioration of operability when performing fine work.

A stepped portion for preventing the cap from falling off may be provided on the tip side of the metal plate. According to this configuration, it is possible to ensure cap prevention and ease of replacement.
The cap can be provided with a protrusion on the inner surface of the calibration weight on the grip side. According to this configuration, a light weight of about 1 g can be easily grasped.

  The grip material can be formed with a recess on the surface where a finger can be inserted. According to this configuration, it is possible to apply force to the power point easily in a more stable state.

  The grip material is integrated with the support material, and can be mounted so as to cover the integrated grip material from the rear end side of the fulcrum portion to the grip force generation portion.

  The grip material integrated with the support material can be provided with a plurality of protrusions for preventing separation at both ends in the width direction on the inner surface side.

  According to the tweezers for gripping a calibration weight according to the present invention, even when a heavy weight is gripped, the burden on the fulcrum portion is small, it is possible to apply a sufficient force to the force point portion, and when performing fine work Deterioration of operability can be avoided.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. 1 to 3 show an embodiment of a tweezer for grasping a calibration weight according to the present invention.

  The calibration weight grasping tweezers 10 shown in these drawings has a structure in which a flat stainless steel plate having a thickness of several millimeters, for example, about 2 mm, is disposed facing each other. The two metal plates are fulcrum portions 12 that are joined and fixed to each other on the base end side by welding or the like. In the case of the present embodiment, the fulcrum portion 12 is thinner than the other portions.

  On the distal end side, a calibration weight gripping portion 14 is provided that is spaced apart at a predetermined interval in the vertical direction. Further, when the calibration weight A is gripped between the fulcrum portion 12 and the gripping portion 14, a gripping force is generated so that the thumb and index finger are brought into contact with each other from above and below so that the metal plates come close to each other. A portion 16 is provided.

  In the tweezers 10 configured as described above, as shown in FIG. 4, the calibration weight is positioned between the gripping portions 14, the force is applied to the gripping generation portion 16, and the metal plates are moved toward each other. Then, the calibration weight can be grasped by the grasping portion 14.

  In this case, the fulcrum part 12 is a region having the same width, for example, about 10 mm, provided on the base end side of the flat metal plate. The gripping part 14 is an area provided on the front end side of the flat metal plate, and is formed in a tapered shape whose width gradually decreases toward the front end side. The gripping force generator 16 is formed at the approximate center of the flat metal plate and has a maximum width, for example, a width of about 13 mm.

  And the level | step-difference part 17 of the form notched in the location which opposes a part of side surface is provided in the front end side of the metal plate. A region on the tip side of the stepped portion 17 is a gripping portion 14.

  The fulcrum part 12 is covered with a flexible support material 18 formed of synthetic resin or rubber. Further, the gripping portion 14 maintains a frictional force with the calibration weight A and is covered with a pair of caps 20 for preventing heat conduction. The cap 20 is made of synthetic resin, rubber, or the like, and the rear end side enters the stepped portion 17.

  In the case of the present embodiment, the cap 20 is provided with a convex portion 20a so as to be positioned on the inner surface on the gripping side of the calibration weight A, as shown in detail in FIG. In the example shown in FIG. 4, the convex portion 20 a is provided on the inner and outer surfaces of the cap 20, but may be provided only on the inner surface side.

  Further, the gripping force generating portion 16 is covered with a slip prevention grip 22 made of synthetic resin or rubber. In the case of the present embodiment, a recess 22 a into which the belly or tip of a finger can be inserted is provided at the center of the surface side of the grip 22.

  The balance / balance tweezers 10 for gripping a calibration weight configured as described above is a metal tweezer having a relatively long overall length capable of operating a calibration weight A up to about 1 kg.

  Moreover, according to the tweezers 10 configured as described above, the following operational effects can be obtained. Since two flat metal plates with a thickness of several mm or more are arranged facing each other and have the fulcrum part 12 joined and fixed to each other on the base end side, sufficient rigidity can be secured, Since the fulcrum part 12 is covered with a flexible support material 18 formed of synthetic resin or rubber, when the fulcrum part 12 is grasped with the little finger and the palm, the burden on the finger is eased and functions as a reliable fulcrum. Can be demonstrated.

  In addition, the gripping force generator 16 is a region of the maximum width formed at the approximate center of the metal plate and is covered with a grip material 22 for preventing slipping formed of synthetic resin or rubber. Sufficient power can be applied.

  Furthermore, the gripping portion 14 is formed of a tapered region formed on the front end side of the metal plate, maintains the frictional force with the calibration weight A, and is covered with the cap 20 for preventing heat conduction. Without transferring heat to the working weight A, it is possible to avoid deterioration in operability when performing fine work.

  In addition, since the tweezers 10 includes the support member 18, the cap 20, and the grip 22, for example, even when a measurement manager repeatedly performs calibration of the measuring instrument all day, the burden on fingers and hands At the same time, reliable gripping operability is ensured, heat transfer from the hand to the calibration weight A, which causes errors during calibration, and reduction of convection due to the heat of the human body in the windshield are achieved. Is done.

  Further, the fulcrum portion 12 of the tweezers 10 is provided with a support material 18 made of a material such as resin or rubber, which is widened and is held when gripped by the little finger, the ring finger, and the palm portion facing the holding thereof. In addition to reducing the burden on the hands, at the same time, the function as a reliable fulcrum is demonstrated to increase the safety of weight change.

  Furthermore, the gripping force generating portion 16 (power point portion) that is mainly sandwiched between the thumb and the index finger is made the widest region than the other portions of the tweezers 10, so that even when a heavy calibration weight A is gripped, the fulcrum is supported. The burden on the part 12 is small, it is possible to apply a sufficient force to the force point part, and it is possible to avoid deterioration in operability when performing fine work.

  The gripping force generator 16 is wider than the other parts of the tweezers 10 so that it can be easily gripped. On the other hand, by changing the width, the gripped part can be clearly seen.

  Since the cap 20 is a cushioning material between the tweezers 10 and the weight A, it is used under the condition that it is exhausted by repeated use and easily falls off. Therefore, a stepped portion 17 for facilitating prevention and replacement of the cap 20 is provided at the tip of the tweezers 10.

  In the case of the present embodiment, the cap 20 is made of a material that has a relatively high coefficient of friction, such as rubber, and at the same time a material that does not elute solvents that contaminate the balance. The inner surface on the weight A side is relatively light. A convex portion 20a is provided so that a neck of a small weight can be gripped. This convex portion 20a functions as shown in FIG. 4. In FIG. 4, the left side is the heaviest calibration weight A1 of about 1 kg, and the right side is an example of gripping a light calibration weight A2 of about 2 g.

  When the convex portion 20a is provided on the cap 20, since the inner diameter of the neck portion is large in the heavy and large calibration weight A1, the entire cap 20 including the convex portion 20a enters the neck portion and contacts the inner surface thereof. On the other hand, with the light calibration weight A2, the entire cap 20 cannot be inserted into the neck portion, but the convex portion 20a can invade and contact the inner surface thereof. Can be gripped.

Furthermore, in the case of the present embodiment, the grip material 22 is formed with a concave portion 22a on the surface of which the finger can be inserted. With this configuration, the grip material 22 can be more stably and easily. Can be applied to the power point.
FIG. 5 shows another embodiment of the calibration weight gripping tweezers according to the present invention. The same or corresponding parts as those in the above embodiment are designated by the same reference numerals and the description thereof is omitted. Only the point will be described.

  The tweezers 10a shown in the figure has a fulcrum portion 12 in which two flat metal plates are arranged facing each other and bonded and fixed to each other on the base end side in the same manner as in the above embodiment, and a gripping portion on the tip end side. 14, and a gripping force generator 16 is provided between the fulcrum part 12 and the gripper 14.

  In the case of this embodiment, the cap 20 is attached to the grip portion 14, and the grip material 220 that covers the grip force generation portion 16 is integrated with the support material that covers the fulcrum portion 12 shown in the above embodiment.

  The integrated grip material 220 has a bifurcated shape having a predetermined width, the proximal end side is in a bag shape, and the pair of branched distal ends have a width direction. A plurality of protrusions 221 are provided at the end portions of the two portions so as to face each other with a predetermined interval.

  As shown in FIG. 5B, the grip material 220 having such a shape is mounted so that the fulcrum part 12 is inserted into the inside from the rear end side of the fulcrum part 12 and the front end side covers the gripping force generation part 16. To do.

  When the grip material 220 integrated with the support material in this way is attached, the end in the width direction of the gripping force generating portion 16 abuts between the protrusions 221 to prevent the grip material 220 from being detached. It has become. The same effect as that of the above embodiment can be obtained by the calibration weight grasping tweezers 10a configured as described above.

  According to the tweezers for gripping a calibration weight according to the present invention, even when a heavy weight is gripped, the burden on the fulcrum portion is small, it is possible to apply a sufficient force to the force point portion, and when performing fine work Deterioration of operability can be avoided, and heat conduction is reduced by covering the surface that humans mainly touch with resin with tweezers made of the same material for weights made mainly of stainless steel. In addition, it reduces heat convection due to the temperature rise of the weight, realizes accurate calibration work, and can be used effectively in the field of weight measurement.

It is a side view of the tweezers for holding calibration weight according to the present invention. FIG. 2 is a top view of FIG. 1. 1 is an explanatory view of the tip side. 1 is an explanatory diagram when gripping weights having different weights with tweezers. It is explanatory drawing which shows the other Example of the tweezers for a calibration weight holding | gripping concerning this invention.

Explanation of symbols

10 tweezers 12 fulcrum part 14 gripping part 16 gripping force generating part 18 support material 20 cap 22 grip

Claims (6)

Calibration that has two flat metal plates facing each other and has a fulcrum part bonded and fixed to each other on the base end side, making the thickness of the fulcrum part thinner than the other parts, and separating them up and down on the tip side In addition to providing a weight holding portion, a holding force generating portion is provided between the fulcrum portion and the holding portion, and the flat metal plates are moved close to each other by the force applied to the holding force generating portion. , Tweezers capable of gripping the calibration weight with the gripping part,
The fulcrum portion is a region of the same width formed on the base end side of the metal plate,
The gripping force generating portion is a region having a maximum width formed at a substantially central portion of the metal plate, and the gripping portion is formed by a tapered region formed at the tip side of the metal plate
The fulcrum part is covered with a flexible support material formed of synthetic resin or rubber,
The grip force generation part is covered with a slip material for preventing slip formed of synthetic resin or rubber,
The gripping portion for holding a calibration weight is characterized in that the gripping portion maintains a frictional force with the calibration weight and is covered with a heat conduction preventing cap.   2. The tweezers for holding a calibration weight according to claim 1, wherein a stepped portion for preventing the cap from falling off is provided on a front end side of the metal plate.   The tweezers for gripping a calibration weight according to claim 1 or 2, wherein the cap is provided with a convex portion on the inner surface of the calibration weight.   The tweezers for grasping a calibration weight according to any one of claims 1 to 3, wherein the grip material has a concave portion in which a finger can be inserted on a surface thereof.   The grip material is integrated with the support material, and is mounted so as to cover the integrated grip material from the rear end side of the fulcrum portion to the grip force generation portion. The tweezers for holding a calibration weight according to any one of the above.   6. The tweezers for holding a calibration weight according to claim 5, wherein the grip material integrated with the support material has a plurality of protrusions for preventing separation at both ends in the width direction on the inner surface side.

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