Patent ID: 6693245
Filing Date: 2004-02-17
Classification: G01G,G01L,Y10T

Abstract:
An electronic balance comprising:a Roberval'S mechanism including: a fixed section formed on a side in a longitudinal direction (L1) of a first metal block material which is rectangular and has a length of L1 and a width of W1, forming a hollow sect ion having a predetermined shape and penetrating the first metal block material from a front surface side to a rear surface side of the first metal block material; a mobile section formed on another side in the longitudinal direction (L1) of the first block material and movable in a vertical direction with respect to the fixed section upon receiving a load of a substance to be weighed; a pair of upper and lower parallel Roberval's sections which have substantially the same length so as to link the fixed section and the mobile section in upper and lower regions respectively in the longitudinal direction (L1) of the first metal block material, each of the pair of upper and lower parallel Roberval's sections has a predetermined thickness; a lever fixed section formed under the upper parallel Roberval's section and in parallel with the upper and lower parallel Roberval's sections, in the longitudinal direction (L1) of The first metal block material; a plurality of thin-wall spring sections formed at ends of the upper and lower parallel Roberval's sections respectively, in the longitudinal direction (L1) of the first metal block material; and a substantially rectangular lever housing section formed on a bottom surface of the lever fixed section from a center section of one side surface of the fixed section of the Roberval's mechanism toward an inside of the Roberval's mechanism, such that the rectangular lever housing section is open from a side surface side of the first metal block material to The hollow section to reach a mobile section side; and a lever including; a base end section formed at one end in a longitudinal direction (L2) of a second metal block material by forming a substantially U-shaped grounded section penetrating the second metal block material from a front surface side to a rear side surface of the second metal block material, the second metal block material having a length L2 which substantially corresponds to a distance from a deepest portion of the lever housing section to a distal end portion, and a width W2 which is smaller than the width of W1 of the first metal block material of the Roberval's mechanism and a diameter of an opening of the lever housing section; a free end section formed at another end in the longitudinal direction (L2) of the second metal block material; a fixed section formed between the base end section and the free end section, along the longitudinal direction (L2) of the second metal block material; a plurality of mobile sections formed at both sides and a lower surface of the fixed section in the longitudinal direction (L2) of the second metal block material; one or more fulcrums which are respectively provided at both end sides of the substantially U-shaped grounded section in the longitudinal direction (L2) of the second metal block material and link the fixed section and the mobile sections; and one or more thin-wall spring sections which are provided in respective positions to correspond to said one or more fulcrums along the longitudinal direction (L2) of the second metal block material, and connect the fixed section and the mobile sections to transmit a force therebetween, wherein the lever is inserted through the opening of the lever housing section of the Roberval's mechanism, housed in the lever housing section, and fixed to the ever fixed section of the Roberval's mechanism, with the free end section of the lever extended to an external portion of the Roberval's mechanism.