US 4,071,104 A · Scale adjustment device

Abstract

A combination of a leaf spring scale and an ajustment spring device for varying or otherwise correcting manufacturing tolerance differences effecting the spring rate of the leaf springs of the scale. Manufactured leaf springs can have a widely divergent spring rate even with small differences in thickness. The adjustment spring device in combination with the leaf springs provides a combined or overall spring rate which is the same for each scale.

Drawings

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Drawings

Claims6

Dependent claims

In combination, an adjustment spring and a leaf spring scale, said adjustment spring for correcting for differences in spring rates of the leaf springs of the scale which result from differences in manufacturing tolerances, the combination comprising:

a scale support;
a weighing pan for receiving a load to be weighed, said weighing pan moving through at least a portion of a weighing range in response to said load;
a first and second leaf spring means operatively connected together for forming and effectively functioning as a unitized leaf spring means, said weighing pan being supported by said first and second leaf spring means, said first and second leaf spring means being carried by said scale support;
and
an adjustment spring means operatively connected between the movable weighing pan and the scale support, said adjustment spring means including a coil spring having a spring support means on one end thereof, a screw thread means affixed to the spring support means, said screw thread means extending through a middle portion of said coil spring, an adjustable rotative nut-type element rotatively disposed upon said screw thread means and extending between coil elements of said coil spring, the nut-type element being rotatively adjustable to different positions upon said screw thread means to vary an effective working length of said coil spring, and hence, to vary a spring rate of said coil spring, whereby the adjustment spring means in combination with said first and second leaf spring means can effectively adjust an overall spring rate of the scale and correct for inherent differences due to manufacturing tolerances of said first and second leaf spring means.

2 more elements

Dependencies are inferred from the claim text.

Description2,157 words

Summary582 words

#The invention relates to leaf spring scales, and more particularly to an adjustment device for correcting manufacturing differences in the leaf springs, which manufacturing differences effect the spring rate of the scale.

#In the past, many devices have been proposed for correcting operational errors for scales. Usually these devices include adding additional compensatory springs, such as may be seen in the patent to: Gerald C. Freeman; U.S. Pat. No. 3,807,517; issued Apr. 30, 1974.

#Recently, there has been invented a scale whose leaf springs are automatically self-compensating for errors in the spring rate over the entire weighing range. Such a scale is shown in the U.S. Pat. No. 4,022,288 to Louis T. Canevari.

Brief description of the drawings3 figures

#These and other objects of this invention will be better understood and will become more apparent with reference to the following detailed description taken in conjunction with the accompanying drawings, in which:

#FIG. 1 is a perspective view of the leaf spring scale and adjustment spring combination of this invention;

#FIG. 2 is a front view of FIG. 1; and

Detailed description1,498 words

#Referring to FIGS. 1 and 2, a Box-like leaf spring scale 10 is illustrated with an adjustable spring mechanism 27 in combination.

#The scale basically consists of a weighing pan 11, a combination of leaf spring strips 12, a common tare support 13, a scale frame 14, and a deflection measuring apparatus 15.

#For most leaf spring scales, the spring constant "K" is usually given by the following equation:

Facts

Application

05/735,581Filed 26 Oct 1976

Granted

31 Jan 1978

Term ended

31 Jan 1995

Estimated · how

Pre-1995 term; greater of 17 years from grant or 20 years from filing when eligible. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification3 codes

G01G 3/08
Weighing apparatus characterised by the use of elastically-deformable members, e.g. spring balances: wherein the weighing element is in the form…
G01G 23/14
Auxiliary devices for weighing apparatus: devices for determining tare weight or for cancelling out the tare by zeroising, e.g. mechanically operated
G01G
Weighing

Scale adjustment device

Life of this patent

Scale adjustment device

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims6

Description2,157 words

Drawings

Classification3 codes

Life of this patent

Description2,157 words