US 4,936,399 AGranted

Hand held weighing scale

OwnerRichard E. Christman, Steven E. Baumanninventors

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Abstract

A scale arranged and constructed of relatively small size to be hand held and portable for use in weighing relatively light articles such as fish and the like. The scale operates on a capacitance measuring concept wherein an initial capacitance between two conductive, spaced and insulated plates is measured with a change in distance between the two plates caused by a load is measured and, through a logic circuit, converted to a digital read-out. The capacitance sensor unit for the measuring of the capacitance caused by the load includes a stationary plate and a moveable plate insulated from each other with proper leads connecting the plates to the logic circuit. The entire capacitance measuring device is provided in a sandwiched arrangement to provide a small and compact unit. The logic circuitry provides for digital readout and provides automatic zeroing.

Claims16

Dependent claims

A hand held, portable scale including:

a. a housing providing a substantially sealed interior for housing the scale components and having a portion thereof formed to provide a handle for holding the same;
b. a logic circuit arranged within said cavity;
c. means for energizing said circuit including a power source arranged within said housing;
d. readout means including digital readout facility connected to said logic circuit and arranged and constructed to be readable exteriorally of said housing;
e. capacitance measuring means arranged within said cavity and connected to said logic circuit for the transmission of a signal to said logic circuit, said signal being generated in response to changes in capacitance thereof;
f. said capacitance measuring and signal generating means including:
1. a first plate member having at least one conductive side and having a movable portion;
2. a second plate member having at least one conductive side;
3. means for retaining said second plate member in stationary position with respect to said moveable portion of said first plate;
4. said conductive sides of said first and second plate members being arranged in spaced, face-to-face relation;
g. means for connecting a weight to be measured to said capacitance measuring means, said means extending through the housing whereby the connected weight provides a capacitance change signal transmitted to said logic circuit from said measuring means and said logic circuit converting said signal to said digital readout means;
i. said weight connecting means being attached to said moveable portion of said first plate whereby placing of a weight upon said connecting means will increase the distance between said conductive first and second surfaces of said plate members.

9 more elements

Dependencies are inferred from the claim text.