US3814188A — Electronic draft load sensing system

Claim 1

Independent Claim 193 words

A draft load sensing system on a vehicle comprising, a vehicle, at least one draft arm, at least one crossbar including means rigidly mounting said crossbar on said vehicle for bending said crossbar responsive to draft loads on said draft arm, means on said crossbar supporting one end of said draft arm for universal movement, a hydraulic system including a hydraulic motor means mounted on said vehicle and connecting means connected between said motor means and said draft arm for raising and lowering said draft arm, a hydraulic valve in said hydraulic system for controlling the operation of said hydraulic motor means, a strain gauge means mounted on said crossbar between the mounting on said vehicle and the connection to said draft arm for generating a signal responsive to bending strain in said bar, an electronic amplifier circuit connected to said strain gauge for amplifying the signal, an electrical control means on said hydraulic valve connected to said amplifier for opening and closing said valve to said motor means and raising and lowering said draft arm responsive to an increase and decrease of the draft load on said draft arm bending said crossbar.

Claim 2

Dependent Claim 193 words

A draft load sensing system on a vehicle comprising, a vehicle, at least one draft arm, at least one crossbar including means rigidly mounting said crossbar on said vehicle for bending said crossbar responsive to draft loads on said draft arm, means on said crossbar supporting one end of said draft arm for universal movement, a hydraulic system including a hydraulic motor means mounted on said vehicle and connecting means connected between said motor means and said draft arm for raising and lowering said draft arm, a hydraulic valve in said hydraulic system for controlling the operation of said hydraulic motor means, a strain gauge means mounted on said crossbar between the mounting on said vehicle and the connection to said draft arm for generating a signal responsive to bending strain in said bar, an electronic amplifier circuit connected to said strain gauge for amplifying the signal, an electrical control means on said hydraulic valve connected to said amplifier for opening and closing said valve to said motor means and raising and lowering said draft arm responsive to an increase and decrease of the draft load on said draft arm bending said crossbar.

Claim 3

Dependent Claim 31 words

A draft load sensing system on a vehicle as set forth in claim 1 including said means supporting said crossbar being transverse relative to said vehicle for bending on its axis.

Claim 4

Dependent Claim 52 words

A draft load sensing system on a vehicle as set forth in claim 1 including two lower draft arms, means supporting one end of each of said lower draft arms for universal movement to said crossbar to thereby generate a signal in response to the draft load applied to said draft arms.

Claim 5

Dependent Claim 73 words

A draft load sensing system on a vehicle as set forth in claim 1 including a protective sleeve enclosing said crossbar, means defining a clearance between said crossbar and said sleeve on the outboard portions of said crossbar, two lower draft arms, means connecting a draft arm on each of the outboard ends of said crossbar to thereby provide means for bending said bar in response to draft loads on said draft arms.

Claim 6

Dependent Claim 62 words

A draft load sensing system on a vehicle as set forth in claim 1 including two strain gauges positioned on said crossbar including means positioning one of said strain gauges on one side of said crossbar, means positioning the second gauge on the opposite side of said crossbar to thereby generate a signal in response to draft loads on said draft arms.

Claim 7

Dependent Claim 79 words

A draft load sensing system on a vehicle as set forth in claim 1 including a three-point hitch having an upper draft link and two lower draft arms including said one draft arm, said connecting means for raising and lowering said draft arm including a rock shaft positioned on said vehicle, a pair of rock arms connected through lift links to raise and lower said draft arms in response to the draft load applied to said lower draft arms.

Claim 8

Dependent Claim 65 words

A draft load sensing system on a vehicle as set forth in claim 1 including a sleeve enclosing said crossbar, means defining a clearance between said sleeve of said crossbar where said crossbar is connected to said draft arm whereby the clearaNce between the outboard end of said crossbar and the internal periphery of said sleeve provide an overload limit for bending of said crossbar.

Claim 9

Dependent Claim 101 words

A draft load sensing system on a vehicle as set forth in claim 1 including a three point hitch having two lower draft arms, a sleeve connected to said vehicle, a pair of crossbars received within the said sleeve, means for fastening the inner ends of said crossbars to said sleeve, one of said lower draft arms connected to an outer end of each of said crossbar, a strain gauge positioned on one side of said crossbar and the opposing side of the other crossbar to thereby generate a signal in response to draft loads applied to said lower draft arms.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1977-06-03	1977-12-03	1978-06-04	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1981-06-03	1981-12-03	1982-06-04	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1985-06-03	1985-12-03	1986-06-04	$7700.00	Window Closed / Lapsed

Electronic draft load sensing system

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