ELECTRICAL BALANCE INCLUDING MONITORING MEANS

• US 3,789,937 A
• Filed: 06/25/1973
• Issued: 02/05/1974
• Est. Priority Date: 06/27/1972
• Status: Expired due to Term

• Current Assignee: Mettler-Toledo AG IM Langacher Greifensee Switzerland
• Original Assignee: Felix Strobel, Heinz Allenspach
• Inventors: Strobel, Felix, Allenspach, Heinz
• Primary Examiner(s): Miller, Jr., George H.
• Application Number:
  US05/373,003
• Time in Patent Office: 225 Days
• Field of Search: 177/DIG.1,DIG.3,210
• US Class Current: 177/210.00R
• CPC Class Codes: G01G 23/37 involving digital counting
• CPC Class Codes: G01G 23/46 Devices preventing recording until the weighing mechanism has come to rest
• CPC Class Codes: G01G 3/16 measuring variations of frequency of oscillations of the body
• CPC Class Codes: G01G 7/04 with means for regulating the current to solenoids
• CPC Class Codes: Y10S 177/03 Digitizers electrical

Abstract

An improved electrical balance is disclosed of the type including stationary and load-responsive movable components, means being provided for supplying to signal evaluating means an analog load signal having a function that varies with load, said evaluation means being periodically operable during successive measuring periods to produce digitalized measurements that correspond with the load. The invention is characterized by the provision of balance monitoring means that disable the evaluation means in the event that movement of the movable balance component exceeds predetermined limits during the measurement period. The monitoring means further effects the transfer of each digitalized measurement result to associated data storage means only when the movement of the movable component has not exceeded the predetermined limits during the corresponding measurement period. In balances including load compensation means, the load signal may be the compensation current that is supplied to the compensation coil means.

Claims

1. In a weighing apparatus including stationary and loadresponsive movable components, means for generating a load signal as a function of the load applied to said load-responsive movable component, and load signal evaluation means periodically operable during successive measuring periods to produce digital measurement results that correspond with a given property of said load signal;

the improvement which comprises balance monitoring means (14,

     67) connected with said load signal generating means for disabling said load signal evaluation means when the movement of said movable component exceeds at least one of a set of predetermined limits relative to said stationary component during a given measurement period.

2. Apparatus as defined in claim 1, and further including means (18) for adjusting said predetermined limits.

3. Apparatus as defined in claim 1, and further including signal indicator means (12a) operable from a first condition to a second condition by said balance monitor means at the end of a measurement period during which the movable component remained within its defined limits.

4. Apparatus as defined in claim 1, and further including data storage means (13) for storing digitalized results;

said balance monitoring means being operable at the end of a measuring period during which said predetermined limits have not been exceeded to cause said load signal evaluation means to transmit to the storage means the digitalized measurement that was achieved during said measuring period.

5. Apparatus as defined in claim 1, wherein said balance monitoring means (67) further includes trigger means (72) for enabling said evaluation means when the movement of said movable component returns within said predetermined limits.

6. Apparatus as defined in claim 5, wherein said balance monitoring means further includes time delay means for delaying for a given period of time after the movement of said movable component has returned within said predetermined limits the enabling of said load signal evaluation means.

7. Apparatus as defined in claim 5, wherein said balance monitoring means resets the load signal evaluation means to zero when the movement of the movable component exceeds said predetermined limits.

8. Apparatus as defined in claim 7, and further including means operable when the movement of said movable component returns within said predetermined limits during said measuring cycle for reactivating said load signal evaluation means, whereby the necessity of waiting for the expiration of the former measuring cycle is eliminated.

9. Apparatus as defined in claim 1, and further including means (23b) for defining within said first set of limits a lower set of predetermined limits for controlling the operation of said evaluation means.

10. Apparatus as defined in claim 9, and further including means (FF2) for disabling said evaluation means at the end of a given measuring period during which the lower limits were exceeded an uneven number of times.

11. Apparatus as defined in claim 9, and further including first bistable means (FF1) operable from a first condition to a second condition when the movable component exceeds said first predetermined limits during a given measuring period, second bistable means (FF2) operable alternately between first and second conditions each time during said given measuring period the movable component exceeds said lower predetermined limits, and means (FF3) for generating a presignal when said first and second bistable means are in their first and second conditions, respectively, at the end of said given measuring period.

12. Apparatus as defined in claim 11, and further including means (FF4) for generating a standstill signal after a predetermined time delay period following the generation of said presignal, said evaluation means being operable by said standstill signal to deliver a valid digitalized measurement result obtained during said given measuring period.