Weight sensing device

Claim 1

A device for sensing the weight of an object, comprising: a first circuit including a pair of confronting and spaced-apart electrically conductive members, said circuit being adapted for connection with a signal producing source for producing an oscillatory excitation signal across said electrically conductive members; a second circuit including a junction and a pair of confronting and spaced-apart electrically conductive members connected directly to said junction, said second-mentioned members being spaced from said first-mentioned members; support means adapted to support said object; an electrically conductive coupling member including a first portion positioned between said first-mentioned members and a second portion positioned between said second-mentioned members for capacitively coupling said second circuit to said first circuit, said coupling member being mounted with said support means for movement relative to said first and second-mentioned members in response to the weight of said object when the latter is supported by said support means, said second circuit in response to said excitation signal producing at said junction an oscillatory output signal the amplitude of which is proportional to the position of said coupling member and, therefore, indicative of the weight of said object.

Claim 2

A device for sensing the weight of an object, comprising: a first circuit including a pair of confronting and spaced-apart electrically conductive members, said circuit being adapted for connection with a signal producing source for producing an oscillatory excitation signal across said electrically conductive members; a second circuit including a junction and a pair of confronting and spaced-apart electrically conductive members connected directly to said junction, said second-mentioned members being spaced from said first-mentioned members; support means adapted to support said object; an electrically conductive coupling member including a first portion positioned between said first-mentioned members and a second portion positioned between said second-mentioned members for capacitively coupling said second circuit to said first circuit, said coupling member being mounted with said support means for movement relative to said first and second-mentioned members in response to the weight of said object when the latter is supported by said support means, said second circuit in response to said excitation signal producing at said junction an oscillatory output signal the amplitude of which is proportional to the position of said coupling member and, therefore, indicative of the weight of said object.

Claim 6

A device for sensing the weight of an object, comprising: a first circuit including a first pair of confronting and spaced-apart electrically conductive members, said circuit being adapted for connection with a signal producing source for producing a substantially square wave excitation signal across said first pair of members; a second circuit including a second pair of confronting and spaced-apart electrically conductive members and a single junction connected to said second members, said second members being in alignment with and spaced from said first members; support means adapted to support said object; an electrically conductive coupling member including a first portion positioned between said first members and a second portion positioned between said second members for capacitively coupling said second circuit to said first circuit, said coupling member beiNg electrically insulated from and mounted to said support means for movement relative to said first and second pairs of members in response to the weight of said object when the latter is supported by said support means, said second circuit in response to said excitation signal producing at said junction a square wave output signal, the peak-to-peak amplitude of which is proportional to the position of said coupling member; a third circuit connected with the junction of said second circuit and including means for converting said square wave output signal into a direct current signal having a magnitude proportional to the peak-to-peak amplitude of said output signal, said third circuit further including means responsive to said direct current signal for producing a current, the magnitude of which is proportional to the magnitude of said direct current signal; and means connected with said last-mentioned means and operationally connected with said coupling member for applying a force to the latter in response to and proportional to said current, said force being equal and opposite to the gravitational force of said object for terminating movement of said coupling member whereby the magnitude of said current producing said equal and opposite force is linearly proportional to the weight of said object.

Claim 7

A device for sensing the weight of an object, comprising: a first circuit including a first pair of confronting and spaced-apart electrically conductive members, said circuit being adapted for connection with a signal producing source for producing a substantially square wave excitation signal across said first pair of members; a second circuit including a second pair of confronting and spaced-apart electrically conductive members and a single junction connected to said second members, said second members being in alignment with and spaced from said first members; support means adapted to support said object; an electrically conductive coupling member including a first portion positioned between said first members and a second portion positioned between said second members for capacitively coupling said second circuit to said first circuit, said coupling member beiNg electrically insulated from and mounted to said support means for movement relative to said first and second pairs of members in response to the weight of said object when the latter is supported by said support means, said second circuit in response to said excitation signal producing at said junction a square wave output signal, the peak-to-peak amplitude of which is proportional to the position of said coupling member; a third circuit connected with the junction of said second circuit and including means for converting said square wave output signal into a direct current signal having a magnitude proportional to the peak-to-peak amplitude of said output signal, said third circuit further including means responsive to said direct current signal for producing a current, the magnitude of which is proportional to the magnitude of said direct current signal; and means connected with said last-mentioned means and operationally connected with said coupling member for applying a force to the latter in response to and proportional to said current, said force being equal and opposite to the gravitational force of said object for terminating movement of said coupling member whereby the magnitude of said current producing said equal and opposite force is linearly proportional to the weight of said object.

Claim 8

A device for sensing the weight of an object, said device comprising: a first circuit adapted for connection with a signal producing source for producing a square wave excitation signal; a second circuit spaced from said first circuit and including an output junction; support means adapted to support said object; coupling means mounted to said support means for movement in response to the weight of said object, said coupling means capacitively coupling said excitation signal to said second circuit for producing at said junction a square wave output signal having a peak-to-peak amplitude dependent upon the position of said coupling means; means connected with said junction and responsive to said output signal for producing a current, the magnitude of which is dependent upon the peak-to-peak amplitude of said output signal; and means connected with said last-mentioned means and operationally connected with said coupling means for applying a force to the latter in response to and proportional to said current, said force being equal and opposite to the gravitational force of said object for terminating movement of said coupling means whereby the magnitude of said current producing said equal and opposite force is linearly proportional to the weight of said object.

Claim 9

A device for sensing the weight of an object, said device comprising: a first circuit adapted for connection with a signal producing source for producing a square wave excitation signal; a second circuit spaced from said first circuit and including an output junction; support means adapted to support said object; coupling means mounted to said support means for movement in response to the weight of said object, said coupling means capacitively coupling said excitation signal to said second circuit for producing at said junction a square wave output signal having a peak-to-peak amplitude dependent upon the position of said coupling means; means connected with said junction and responsive to said output signal for producing a current, the magnitude of which is dependent upon the peak-to-peak amplitude of said output signal; and means connected with said last-mentioned means and operationally connected with said coupling means for applying a force to the latter in response to and proportional to said current, said force being equal and opposite to the gravitational force of said object for terminating movement of said coupling means whereby the magnitude of said current producing said equal and opposite force is linearly proportional to the weight of said object.

Claim 10

A device for sensing the weight of an object, comprising: a first circuit adapted for connection with a signal producing source for producing a square wave excitation signal; a second circuit spaced from said first circuit and including an output junction; support means adapted to support said object; coupling means mounted to said support means for movement in response to the weight of said object, said coupling means capacitively coupling said excitation signal to said second circuit for producing at said output junction a current having a magnitude dependent upon the position of said coupling means; and means connected with said junction and operationally connected with said coupling means for applying a force to the latter in response to and proportional to said current, said force being equal and opposite to the gravitational force of said object for terminating movement of said coupling means whereby the magnitude of said current producing said equal and opposite force is proportional to the weight of said object.

Claim 11

A device for sensing the weight of an object, comprising: a first circuit adapted for connection with a signal producing source for producing a square wave excitation signal; a second circuit spaced from said first circuit and including an output junction; support means adapted to support said object; coupling means mounted to said support means for movement in response to the weight of said object, said coupling means capacitively coupling said excitation signal to said second circuit for producing at said output junction a current having a magnitude dependent upon the position of said coupling means; and means connected with said junction and operationally connected with said coupling means for applying a force to the latter in response to and proportional to said current, said force being equal and opposite to the gravitational force of said object for terminating movement of said coupling means whereby the magnitude of said current producing said equal and opposite force is proportional to the weight of said object.

Claim 12

A device for sensing the weight of an object, comprising: a first circuit including a pair of confronting and spaced-apart electrically conductive members, said circuit being adapted for connection with a signal producing source for producing an excitation signal across said electrically conductive members; a second circuit including a junction and a pair of confronting and spaced-apart eleCtrically conductive members connected with said junction, said second-mentioned members being spaced from said first-mentioned members; a support member adapted to support said object; an electrically conductive coupling member including a first portion positioned between said first-mentioned members and a second portion positioned between said second-mentioned members for capacitively coupling said second circuit to said first circuit, said coupling member being mounted to and physically connected solely with said support member for movement relative to said first and second-mentioned members in response to the weight of said object, said second circuit in response to said excitation signal and the position of said coupling member producing at said junction an output signal having a characteristic proportional to the position of said coupling member and, therefore, indicative of the weight of said object.

Claim 13

A device for sensing the weight of an object, comprising: a first circuit including a pair of confronting and spaced-apart electrically conductive members, said circuit being adapted for connection with a signal producing source for producing an excitation signal across said electrically conductive members; a second circuit including a junction and a pair of confronting and spaced-apart eleCtrically conductive members connected with said junction, said second-mentioned members being spaced from said first-mentioned members; a support member adapted to support said object; an electrically conductive coupling member including a first portion positioned between said first-mentioned members and a second portion positioned between said second-mentioned members for capacitively coupling said second circuit to said first circuit, said coupling member being mounted to and physically connected solely with said support member for movement relative to said first and second-mentioned members in response to the weight of said object, said second circuit in response to said excitation signal and the position of said coupling member producing at said junction an output signal having a characteristic proportional to the position of said coupling member and, therefore, indicative of the weight of said object.

Claim 14

A device for sensing the weight of an object, comprising: a first circuit adapted for connection with a signal producing source for producing an excitation signal; a second circuit spaced from said first circuit and including an output junction; a support member adapted to support said object; a coupling member capacitively coupling said second circuit to said first circuit, said coupling member being mounted to and physically connected solely with said support member for movement in response to the weight of said object; said second circuit in response to said excitation signal and the position of said coupling member producing at said junction an output signal having a characteristic proportional to the position of said coupling member and, therefore, indicative of the weight of said object.

Claim 15

A device for sensing the weight of an object, comprising: a first circuit adapted for connection with a signal producing source for producing an excitation signal; a second circuit spaced from said first circuit and including an output junction; a support member adapted to support said object; a coupling member capacitively coupling said second circuit to said first circuit, said coupling member being mounted to and physically connected solely with said support member for movement in response to the weight of said object; said second circuit in response to said excitation signal and the position of said coupling member producing at said junction an output signal having a characteristic proportional to the position of said coupling member and, therefore, indicative of the weight of said object.