JPH0631384Y2 - Device for expanding the operating angle of the pointer for thin household scales - Google Patents

Description

[Detailed Description of the Invention] [Field of Use of the Invention] The present invention relates to improvement of small scales, especially household scales.

[Prior Art] In household balances, a method is generally used in which a force is applied to a coiled spring via a Roberval mechanism, and in another form, a leaf spring Roberval shown in West German Patent No. 2447162 and Japanese Patent Publication No. 39-10888. A scale using is also proposed.

[Problems to be Solved by the Invention] The conventional balance scale using a spiral wound spring is not suitable for a thin type because of its structure, and a scale using a leaf spring Roberval also has a problem that the height of the support bar of the Roberval and the magnitude of the eccentric load error are large. Due to the inverse proportion, it was not thin and was tall. In order to make it thin, it is an essential condition to reduce the displacement of the cargo tray. It is an object of the present invention to develop a pointer movement angle enlarging device capable of accurately enlarging a small amount of displacement of a load tray and taking a large movement of a pointer, and to provide a thin and accurate small further scale.

[Means for Solving Problems] (1) The circular motion of the link adjuster is once converted into a linear motion by the link rod, and the linear motion of the link rod is converted into a circular motion by the rack again to expand the link and rack. And share.

(2) The pinion is housed in the pinion holder and the pinion spring has a degree of freedom in the abutting position between the rack and the pinion so as to apply a slight pressure.

(3) A link spring and a rack spring are provided, and
The individual springs cooperate with each other to eliminate unnecessary friction that may adversely affect the operation and ensure stable operation.

[Operation] (1) Sufficient expansion with a small frictional force by using a two-stage expansion mechanism that converts vertical motion into horizontal motion with a small expansion ratio and expands again when horizontal motion is converted into rotational motion (2) Because of the engagement with the link rod, a proper rack-pinion contact is always obtained by allowing the pinion to have a degree of freedom with respect to the uniquely determined rack tooth surface position. (3) The effect of the link spring, rack spring, and pinion spring keeps the play between the link and link rod, the link rod and rack, and the rack and pinion in a certain direction. A scale is obtained.

[Examples] Details thereof will be described below with reference to the accompanying drawings. However, this embodiment is merely an example and is not intended to limit the idea of the invention.

FIG. 1 is a plan view of the inside of a scale using one embodiment of the present invention,
FIG. 2 is a side sectional view thereof, and FIGS. 3 to 7 are enlarged views of a main part.

A link sensor (3), which moves integrally with the support member (1) of the leaf spring Roberval that descends in proportion to the weight of the object to be measured, is fixed so as to extend around the center of the span of the leaf spring. There is. The link sensor may be configured by extending a part of the leg portion of the support member. A link (5) is engaged via a link frame (4) fixed to the fixed side support member (2) so as to be freely rotatable about a link fulcrum (6) which is an engaging point thereof. The contact point (7) between the link and the link frame is located almost at the center of the leaf spring span and forms a link contact (8) protruding from the tip of the short blade of the link. A link adjuster (9) provided with a “V” -shaped groove is screwed to the tip of the link long blade so that the contact with the link rod (10) is constant. The link adjuster (9)
Can be rotated from the outside of the scale by a jig etc. and the link ratio can be adjusted. A hole for contacting the link adjuster is provided at one end of the link rod (10). The link spring (11) pulls the link adjuster to press the link adjuster, and the link contact (8) presses the link sensor (3) with an appropriate force. To be done. The other end of the link rod is loosely attached to the short blade of the rack. The rack (12) is loosely attached under the case in a rotatable state with the rack fulcrum (13) as a fulcrum. The tip surface (15) of the rack long blade forms a part of an arc centered on the rack fulcrum and forms sawtooth teeth. The rack fulcrum is pulled so that the position opposite to the engagement point with the link rod (10) with respect to the rack fulcrum (13) is in the same direction as the direction in which the link spring (11) is drawn by the rack spring (14). It is configured so that the frictional force in 13) does not increase. On the serrated surface (15) of the long blade tip of the rack, a pinion (17) is rotatably incorporated in a pinion holder (16), the rotation axis of which penetrates the upper surface of a scale plate (19) and a pointer (20) is fixed. ) Is in contact. The pinion holder (16) is rotatably engaged under the case at a pinion fulcrum (18), which is the center of rotation, and is pinioned by a pinion spring (21).
The contact between 7) and the serrated surface (15) of the long blade tip of the rack is maintained at an appropriate pressure.

The link frame (4) penetrates the fixed side support member (2) and the frame (22) and has a cylindrical rod (24) provided with a male screw for screwing an adjuster (23) for adjusting the zero point from outside the balance body. ) Is provided, and flexures (26) and (27) are formed between the leg and the middle of the leg and the support member fixing point. The outer shape of the adjuster (23) is larger than the through holes (28) of the supporting member and the frame.

D is the lowering amount of the load tray (29), L1 is the distance between the link contact (8) and the link fulcrum (6), L2 is the distance between the link fulcrum (6) and the tip of the link adjuster (9 '), and the short blade of the rack is When the length is l1 and the length of the long blade of the rack is l2, the descent amount D of the load tray (29) is expanded to L2 / L1 times by the link and further expanded to l2 / l1 times by the rack to contact the pinion. The amount R of movement of the serrated surface (15) at the tip of the long rack blade is (L2 × l2) / (L1 × l1) times the amount D of the receiving tray, which is sufficient to rotate the pinion once when weighing and weighing. .

Rack length wing tip movement amount R corresponding to the receiving tray descent amount D
The adjustment of can be done freely by rotating the link adjuster (9) and changing the length of L2.

The adjuster (23) is rotated in order to accurately set the initial position of the pointer (20) to the zero point. The adjuster (23) has its end face abutting against the frame and retracts the leg (25) of the link frame, and the flexures (26) and (27) are set in a flexed state and adjusted to the position of the pointer (20). The adjuster (23) to adjust the zero point. When the adjuster (23) is rotated clockwise, the leg portion (25) of the link frame is attracted, the link fulcrum (6) moves downward, the link adjuster (9) is pushed out, and the rack (12) rotates clockwise and the pinion ( 17) rotates counterclockwise. When the adjuster (23) is rotated counterclockwise, the link frame is returned by the elastic force of the bending portion, the link fulcrum (6) moves upward, and the pointer (20) rotates clockwise by the same operation as described above. In these operations, there is no change in L1, L2, l1 and l2, and the expansion ratio (L2 × l
2) / (L1 × l1) does not change and only the zero point can be adjusted.

On the other hand, the rotational moment acting on the plate receiving side supporting member (1) differs depending on the position of the center of gravity (M) of the object to be weighed (A), and the movement amount (D) of the supporting member (1) is the same for the same object. Different values are shown, and this tendency is related to the height (H) of the supporting member, and becomes larger as the height (H) of the supporting member becomes lower, which is an obstacle to making the scale thin.

By moving the link sensor that operates integrally with the plate receiving side supporting member (1) to almost the center of the leaf spring span and contacting the link contact, the contact of the corresponding plate is moved by rotation of the plate receiving supporting member (1). The amount of change in the amount is approximately the same as the amount of change in the movement amount (D) of the dish receiving side support member due to the rotation moment, but is approximately the same value, which offsets the amount of change in the movement amount of the dish receiving side support member due to the rotation moment.

[Advantages of the Invention] With the above-described configuration, it is possible to provide a scale that is thin and yet has a small frictional force, a sufficient expansion ratio, high accuracy, and easy to read.

[Brief description of drawings]

Fig. 1 Internal plan view of the embodiment of the present invention Fig. 2 Partial sectional side view of the embodiment of the present invention Fig. 3 Enlarged plan view of link Fig. 4 Partial sectional side view of Fig. 3 Fig. 5 Link frame Partial cross-section enlarged plan view Fig. 6 Partial cross-sectional side view of Fig. 7 Enlarged view of rack 1 …… Plate receiving side support member 2 …… Fixed side support member 3 ...
Link sensor, 4 link frame, 5 link, 6 link fulcrum, 8 link contact, 9 link adjuster, 10 link rod, 11 link spring, 12 rack, 13 ... Rack fulcrum,
14 ... Rack spring, 15 ... Serrated surface, 16 ...
… Pinion holder, 17 …… Pinion, 18 …… Pinion fulcrum, 19 …… Scale plate, 20 …… Indicator, 21 ……
Pinion spring, 22 ... Frame, 23 ... Adjuster, 24 ... Cylindrical rod, 25 ... Leg, 26, 27 ... Deflection part, 28 ... Through hole, 29 ... Packing tray

Claims (1)

[Scope of utility model registration request] 1. A displacement amount of a plate receiving side supporting member of a plate spring Roverval mechanism in which paired plate springs are locked above and below the left and right fixed side supporting members and the plate receiving side supporting member, and the displacement amount is detected. In a thin household scale that changes the direction of the link with the link and shows the weight value written on the scale plate, loosely attach the link rod to the long end of the link with different lengths from the link fulcrum. A link, which is a first enlargement device having a link adjuster provided with a V-groove, is engaged with the fixed-side support member so as to freely rotate about a link fulcrum, which is an engaging point, and a rack fulcrum. The blades from the rack are different lengths, and the rack, which is the second expansion device in which the serrated tooth profile is formed at the tip of the long blade that is a part of the arc centering on the rack fulcrum, is at the engagement point with the base. Freely with a rack fulcrum as a fulcrum The link adjuster is rotatably engaged, and the link rod is brought into contact with the V groove of the link adjuster with an appropriate pressure by the link spring and the rack spring, and the V groove of the link adjuster screwed to the long wing end of the link and the short length of the rack. The pinion that rotates together with the pointer is attached to the pinion holder that is attached to the base so that it can rotate freely around the pinion fulcrum as a fulcrum while connecting to the wing via a link rod. An apparatus for enlarging the pointer operating angle of a thin household scale, which is configured so as to abut against a serrated tooth profile at the tip of the long blade of the above with appropriate pressure.