US3783611A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrostatic transmission control system
Assignee: Eaton Corp
•
Filing: 1972-03-22
•
Granted: 1974-01-08
•
Expires: 1992-03-22
Abstract
Abstract An improved control system for a hydrostatic transmission includes an anti-stall system for preventing overloading of an engine which drives the hydrostatic transmission. The anti-stall system senses the speed at which the engine is operating, the input to output speed ratio of the transmission as indicated by the displacement of one unit of the hydrostatic transmission, and the setting of a throttle for the engine. The anti-stall system utilizes these three inputs to regulate the pressure of control fluid conducted to a speed control valve. The speed control valve is selectively operable to vary the pressure of control fluid conducted to a pressure responsive control motor which adjusts the displacement of a unit of the hydrostatic transmission. The anti-stall system varies the pressure of the control fluid conducted to the speed control valve with variations in the fluid pressure conducted to the control motor from the speed control valve. However in the event of an impending stalling of the engine, the anti-stall system reduces fluid pressure conducted to the speed control valve. The speed control valve opens in response to this decrease in pressure to quickly decrease the fluid pressure to which the control motor is exposed. This effects operation of the control motor to decrease the output speed of the hydrostatic transmission and thereby reduce the load on the engine.
Inventors
- 👤 E Bojas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:49
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/38; F16H61/40; F16H61/46; F16H61/468; F16H61/42
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
147 words
Apparatus for controlling the operation of a hydrostatic transmission having a variable displacement hydrostatic unit connected with a prime mover having a selectively settable throttle, said apparatus comprising motor means for varying the displacement of the hydrostatic unit to vary the output speed of the hydrostatic transmission, means for providing a first signal which varies with variations in the operating speed of the prime mover, means for providing a second signal which varies with variations in the setting of the throttle, means for providing a third signal which varies as a function of variations in the displacement of the hydrostatic unit, and anti-stall means responsive to said first, second and third signals for effecting operation of said motor means to vary the displacement of the hydrostatic unit to reduce the output speed of the hydrostatic transmission upon the occurrence of an impending overloading of the prime mover.
Claim 2
Dependent Claim
147 words
Apparatus for controlling the operation of a hydrostatic transmission having a variable displacement hydrostatic unit connected with a prime mover having a selectively settable throttle, said apparatus comprising motor means for varying the displacement of the hydrostatic unit to vary the output speed of the hydrostatic transmission, means for providing a first signal which varies with variations in the operating speed of the prime mover, means for providing a second signal which varies with variations in the setting of the throttle, means for providing a third signal which varies as a function of variations in the displacement of the hydrostatic unit, and anti-stall means responsive to said first, second and third signals for effecting operation of said motor means to vary the displacement of the hydrostatic unit to reduce the output speed of the hydrostatic transmission upon the occurrence of an impending overloading of the prime mover.
Claim 3
Dependent Claim
84 words
An apparatus as set forth in claim 1 further including control means for porting fluid to said motor means at a pressure corresponding to a desired displacement of the hydrostatic unit in the absence of an impending overloading of the prime mover, said anti-stall means including means for porting fluid to said control means at a pressure which is greater than and which varies as a function of variations in the pressure of the fluid ported from said control means to said motor means.
Claim 4
Independent Claim
42 words
An apparatus as set forth in claim said anti-stall wherein saidanti-stall means includes means for reducing the fluid pressures ported to said control means and to said motor means in response to the occurrence of an impending overloading of the prime mover.
Claim 5
Dependent Claim
32 words
An apparatus as set forth in claim 2 wherein sAid means for providing a third signal includes means for sensing the fluid pressure ported from said control means to said motor means.
Claim 6
Dependent Claim
125 words
An apparatus as set forth in claim 1 wherein said anti-stall means includes valve means for porting fluid at a pressure which varies as a function of said first, second and third signals, said means for providing a first signal including means for conducting to said valve means fluid at a pressure which varies as a function of variations in the operating speed of the prime mover, said means for providing a second signal including means for applying to said valve means a pressure which varies with variations in the throttle setting, said means for providing a third signal includes means for conducting to said valve means fluid at a pressure which varies as a function of variations in the displacement of the hydrostatic unit.
Claim 7
Dependent Claim
69 words
Apparatus as set forth in claim 1 further including control valve means operable between a closed condition and an open condition connecting said motor means in fluid communication with said anti-stall means, said valve means including means for operating said valve means from the closed condition to the open condition in response to operation of said anti-stall means upon the occurrence of an impending overloading of the prime mover.
Claim 8
Dependent Claim
123 words
An apparatus as set forth in claim 1 further including speed control valve means operable from a closed condition to an open condition to port fluid under pressure to said motor means to effect operation of said motor means and a variation in the displacement of the hydrostatic unit, and manually actuatable means for effecting operation of said speed control valve means between the open and closed conditions to effect a desired variation in the displacement of the hydrostatic unit, said speed control valve means including means for effecting operation of said speed control valve means from the closed condition to the open condition in response to operation of said anti-stall means upon the occurrence of an impending overloading of the prime mover.
Claim 9
Dependent Claim
197 words
Apparatus for controlling the operation of a hydrostatic transmission driven by a prime mover, said apparatus comprising motor means for varying the input to output speed ratio of the hydrostatic transmission in response to variations in pressure of a control fluid supplied to said motor means, control means for varying the pressure of the control fluid supplied to said motor means, means for conducting fluid to said control means from a source of control fluid, and anti-stall means for reducing the pressure of control fluid conducted to said control means and to said motor means to effect operation of said motor means to reduce the output speed of the hydrostatic transmission in response to the occurrence of an impending overloading of the prime mover and for maintaining the pressure of the control fluid supplied to said control means at a pressure which is greater than the pressure of the control fluid supplied to said motor means and varying the pressure of the control fluid supplied to said control means as a function of variations in the pressure of the control fluid supplied to said motor means in the absence of an impending overloading of the prime mover.
Claim 10
Dependent Claim
197 words
Apparatus for controlling the operation of a hydrostatic transmission driven by a prime mover, said apparatus comprising motor means for varying the input to output speed ratio of the hydrostatic transmission in response to variations in pressure of a control fluid supplied to said motor means, control means for varying the pressure of the control fluid supplied to said motor means, means for conducting fluid to said control means from a source of control fluid, and anti-stall means for reducing the pressure of control fluid conducted to said control means and to said motor means to effect operation of said motor means to reduce the output speed of the hydrostatic transmission in response to the occurrence of an impending overloading of the prime mover and for maintaining the pressure of the control fluid supplied to said control means at a pressure which is greater than the pressure of the control fluid supplied to said motor means and varying the pressure of the control fluid supplied to said control means as a function of variations in the pressure of the control fluid supplied to said motor means in the absence of an impending overloading of the prime mover.
Claim 11
Dependent Claim
58 words
An apparatus as set forth in claim 8 wherein said anti-stall means includes means for increasing the pressure of the control fluid supplied to said control means in response to a sensing of an increase in the pressure of the control fluid supplied to said motor means in the absence of an impending overloading of the prime mover.
Claim 12
Dependent Claim
37 words
An apparatus as set forth in claim 8 further including means for varying the pressure of the control fluid supplied to said control means as a function of variations in the output speed of the prime mover.
Claim 13
Dependent Claim
166 words
An apparatus as set forth in claim 8 wherein said anti-stall means includes first conduit means for conducting fluid at a first pressure, second conduit means for conducting fluid at a second pressure, means for varying at least one of said first and second pressures as a function of variations in the operating speed of the prime mover, means defining a mixing chamber connected in fluid communication with said first and second conduit means, valve means for varying the rate of flow of fluid from said first and second conduit means into said mixing chamber to vary the fluid pressure in said mixing chamber, actuator means for effecting operation of said valve means as a function of variations in the pressure of the control fluid supplied to said motor means, and means for supplying control fluid to said means for conducting control fluid to said control means at a third pressure which varies as a function of variations in the fluid pressure in said mixing chamber.
Claim 14
Dependent Claim
136 words
An apparatus as set forth in claim 11 wherein said means for supplying control fluid at a third pressure includes pressure regulator means connected in fluid communication with said means for conducting control fluid to said control means and with said mixing chamber for varying said third pressure as a function of variations in the fluid pressure in said mixing chamber and as a function of variations in the setting of a throttle for the prime mover, said pressure regulator means including a valve member, means for applying to said valve member a force which varies as a function of variations in the fluid pressure in said mixing chamber, and means for applying to said valve member a force which varies as a function of variations in the setting of the throttle for the prime mover.
Claim 15
Dependent Claim
169 words
An apparatus as set forth in claim 8 wherein said motor means is operable in a first direction from an initial position to effect operation of the hydrostatic transmission in a forward direction and is operable in a second direction from the initial position to effect operation of the hydrostatic transmission in a reverse direction, said apparatus further including first conduit means for conducting control fluid from said control means to said motor means to effect operation of said motor means in the first direction, second conduit means for conducting control fluid from said control means to said motor means to effect operation of said motor means in the second direction, and valve means for enabling the fluid pressure in said first conduit means to be transmitted to said anti-stall means during operation of said motor means in the first direction and for enabling the fluid pressure in said second conduit means to be transmitted to said anti-stall means during operation of said motor means in the second direction.
Claim 16
Dependent Claim
107 words
An apparatus as set forth in claim 13 wherein said anti-stall means includes means for increasing the pressure of control fluid conducted to said control means in response to an increase in the fluid pressure transmitted to said anti-stall means by way of said valve means during operation of said motor means in one of said first and second directions and for decreasing the pressure of control fluid conducted to said control means in response to a decrease in the fluid pressure transmitted to said anti-stall means by way of said valve means during operation of said motor means in one of said first and second directions.
Claim 17
Dependent Claim
72 words
An apparatus as set forth in claim 8 wherein said control means includes a valve member movable between a closed position and an open position in which control fluid can flow between the source of control fluid and said motor means, and means for moving said valve member from the closed position to the open position in response to a reduction in the pressure of control fluid conducted to said control means.
Claim 18
Dependent Claim
68 words
An apparatus as set forth in claim 8 wherein said control means includes a valve member movable between a closed position and an open position in which said motor means is connected in fluid communication with drain and means for moving said valve member from the closed position to the open position in response to a reduction in pressure of the control fluid conducted to said control means.
Claim 19
Dependent Claim
163 words
Apparatus comprising a variable diplacement fluid pump, fluid motor means for varying the displacement of said pump, control valve means for directing fluid pressure to said fluid motor means and for effecting operation of said fluid motor means by varying the fluid pressure directed to said fluid motor means, means for directing fluid pressure to said valve means, and anti-stall means for varying the fluid pressure directed to said valve means with variations in the fluid pressure directed to said fluid motor means to maintain the fluid pressure directed to said valve means slightly above the pressure directed to said fluid motor means for all displacements of said pump in the absence of an impending stall condition, said anti-stall means including means for sensing an impending stall condition and for lowering the pressure directed to said valve means in response to the sensing of an impending stall condition to immediately effect operation of said motor means to reduce the displacement of said pump.
Claim 20
Dependent Claim
163 words
Apparatus comprising a variable diplacement fluid pump, fluid motor means for varying the displacement of said pump, control valve means for directing fluid pressure to said fluid motor means and for effecting operation of said fluid motor means by varying the fluid pressure directed to said fluid motor means, means for directing fluid pressure to said valve means, and anti-stall means for varying the fluid pressure directed to said valve means with variations in the fluid pressure directed to said fluid motor means to maintain the fluid pressure directed to said valve means slightly above the pressure directed to said fluid motor means for all displacements of said pump in the absence of an impending stall condition, said anti-stall means including means for sensing an impending stall condition and for lowering the pressure directed to said valve means in response to the sensing of an impending stall condition to immediately effect operation of said motor means to reduce the displacement of said pump.
Claim 21
Dependent Claim
82 words
Apparatus as set forth in claim 17 wherein said anti-stall means includes means for sensing variations in the fluid pressure directed to said motor means and pressure regulator means for increasing the pressure of the fluid directed to said valve means in response to an increase in the fluid pressure directed to said motor means and for decreasing the pressure of the fluid directed to said valve means in response to a decrease in the fluid pressure directed to said motor means.
Claim 22
Dependent Claim
39 words
Apparatus as set forth in claim 17 wherein said valve means includes means for varying the pressure of the fluid directed to said fluid motor means in response to variations in the fluid pressure directed to said valve means.
Claim 23
Dependent Claim
55 words
Apparatus as set forth in claim 17 wherein said valve means includes a valve spool and means for moving said valve spool from a closed position at least partially blocking fluid flow to said fluid motor means to an open position in response to a lowering of the fluid pressure directed to said valve means.
Claim 24
Dependent Claim
183 words
Apparatus for controlling the operation of a hydrostatic transmission driven by a prime mover and having a variable displacement hydrostatic unit, said apparatus comprising motor means for varying the displacement of the hydrostatic unit in response to variations in the pressure of control fluid supplied to said motor means, valve means operable between a closed condition and an open condition to regulate a flow of control fluid to said motor means, means for conducting control fluid to said valve means from a source of control fluid, means for operating said valve means from the closed condition to the open condition in which said valve means ports the control fluid to said motor means in response to a reduction in the pressure of the control fluid conducted to said valve means, and anti-stall means for reducing the pressure of the control fluid conducted to said valve means to effect operation of said valve means to the open condition and a porting of relatively low pressure control fluid to said motor means in response to the occurrence of an impending overloading of the prime mover.
Claim 25
Dependent Claim
183 words
Apparatus for controlling the operation of a hydrostatic transmission driven by a prime mover and having a variable displacement hydrostatic unit, said apparatus comprising motor means for varying the displacement of the hydrostatic unit in response to variations in the pressure of control fluid supplied to said motor means, valve means operable between a closed condition and an open condition to regulate a flow of control fluid to said motor means, means for conducting control fluid to said valve means from a source of control fluid, means for operating said valve means from the closed condition to the open condition in which said valve means ports the control fluid to said motor means in response to a reduction in the pressure of the control fluid conducted to said valve means, and anti-stall means for reducing the pressure of the control fluid conducted to said valve means to effect operation of said valve means to the open condition and a porting of relatively low pressure control fluid to said motor means in response to the occurrence of an impending overloading of the prime mover.
Claim 26
Dependent Claim
131 words
An apparatus as set forth in claim 21 further including manually actuatable means movable from an initial position to any one of a plurality of actuated positions spaced different distances from said initial position, means for operating said valve means from the closed condition to the open condition in response to movement of said manually actuatable means from the initial position to any one of said actuated positions to port control fluid to said motor means, and means for operating said valve means from the open condition to the closed condition in response to operation of said motor means to an extent which is a function of the extent of movement of said manually actuatable means from the initial position in the absence of an impending overloading of the prime mover.
Claim 27
Dependent Claim
129 words
An apparatus as set forth in claim 22 wherein said means for operating said vaLve means from the open condition to the closed condition in response to operation of said motor means includes pressure responsive means for operating said valve means to the closed condition in response to an increase in the pressure of the control fluid conducted to said motor means to a pressure corresponding to the extent of movement of said manually actuatable means from the initial position, said anti-stall means being effective to prevent an increase in the pressure of the control fluid conducted to said motor means to a pressure corresponding to the extent of movement of said manually actuatable means from the initial position in response to an impending overloading of the prime mover.
Claim 28
Dependent Claim
76 words
An apparatus as set forth in claim 21 wherein said anti-stall means includes means for maintaining the pressure of the control fluid conducted to said valve means at a pressure which is greater than the pressure of the control fluid supplied to said motor means and for varying the pressure of the control fluid supplied to said valve means as a function of variations in the pressure of the control fluid supplied to said motor means.
Claim 29
Independent Claim
126 words
An apparatus for controlling the operation of a hydrostatic transmission driven by a prime mover and having a variable displacement hydrostatic unit, said apparatus comprising fluid motor means for varying the displacement of the hydrostatic unit in response to variations in control fluid pressure to which said motor means is exposed, pressure controller means operable to anyone of a plurality of settings to vary the control fluid pressure to which said motor means is exposed with variations in the setting of said pressure controller means, and anti-stall means connected in continuous fluid communication with said motor means through said pressure controller means for decreasing the pressure to which said motor means is exposed in response to the occurrence of an impending overloading of the prime mvoer.
Claim 30
Independent Claim
126 words
An apparatus for controlling the operation of a hydrostatic transmission driven by a prime mover and having a variable displacement hydrostatic unit, said apparatus comprising fluid motor means for varying the displacement of the hydrostatic unit in response to variations in control fluid pressure to which said motor means is exposed, pressure controller means operable to anyone of a plurality of settings to vary the control fluid pressure to which said motor means is exposed with variations in the setting of said pressure controller means, and anti-stall means connected in continuous fluid communication with said motor means through said pressure controller means for decreasing the pressure to which said motor means is exposed in response to the occurrence of an impending overloading of the prime mvoer.
Claim 31
Independent Claim
199 words
An apparatus for controlling the operation of a hydrostatic transmission driven by a prime mover and having a variable displacement hydrostatic unit, said apparatus comprising fluid motor means for varying the displacement of the hydrostatic unit in response to variations in control fluid pressure to which said motor means is exposed, pressure controller means operable to anyone of a plurality of settings to vary the control fluid pressure to which said motor means is exposed with variations in the setting of said pressure controller means, and anti-stall means connected in fluid communication with said motor means through said pressure controller means for decreasing the pressure to which said motor means is exposed in response to the occurrence of an impending overloading of the prime mover, said pressure controller means including valve means operable between a first condition varying the control fluid pressure to which said motor means is exposed and a second condition in which the control fluid pressure to which said motor means is exposed is maintained substantially constant and passage means for connecting said anti-stall means in fluid communication with said motor means when said valve means is in either the first condition or the second condition.
Claim 32
Independent Claim
199 words
An apparatus for controlling the operation of a hydrostatic transmission driven by a prime mover and having a variable displacement hydrostatic unit, said apparatus comprising fluid motor means for varying the displacement of the hydrostatic unit in response to variations in control fluid pressure to which said motor means is exposed, pressure controller means operable to anyone of a plurality of settings to vary the control fluid pressure to which said motor means is exposed with variations in the setting of said pressure controller means, and anti-stall means connected in fluid communication with said motor means through said pressure controller means for decreasing the pressure to which said motor means is exposed in response to the occurrence of an impending overloading of the prime mover, said pressure controller means including valve means operable between a first condition varying the control fluid pressure to which said motor means is exposed and a second condition in which the control fluid pressure to which said motor means is exposed is maintained substantially constant and passage means for connecting said anti-stall means in fluid communication with said motor means when said valve means is in either the first condition or the second condition.
Claim 33
Independent Claim
220 words
An apparatus for controlling the operation of a hydrostatic transmission driven by a prime mover and having a variable displacement hydrostatic unit, said apparatus comprising fluid motor means for varying the displacement of the hydrostatic unit in response to variations in control fluid pressure to which said motor means is exposed, pressure controller means operable to anyone of a plurality of settings to vary the control fluid pressure to which said motor means is exposed with variations in the setting of said pressure controller means, anti-stall means connected in fluid communication with said motor means through said pressure controller means for decreasing the pressure to which said motor means is exposed in response to the occurrence of an impending overloading of the prime mover, means for providing a first signal which varies with variations in the operating speed of the prime mover, means for providing a second signal which varies with variations in the setting of a throttle for the prime mover, and means for providing a third signal which varies as a function of variations in the displacement of the hydrostatic unit, said anti-stall means including means responsive to said first, second and third signals for reducing the control fluid pressure to which said motor means is exposed upon the occurrence of an impending overloading of the prime mover.
Claim 34
Independent Claim
220 words
An apparatus for controlling the operation of a hydrostatic transmission driven by a prime mover and having a variable displacement hydrostatic unit, said apparatus comprising fluid motor means for varying the displacement of the hydrostatic unit in response to variations in control fluid pressure to which said motor means is exposed, pressure controller means operable to anyone of a plurality of settings to vary the control fluid pressure to which said motor means is exposed with variations in the setting of said pressure controller means, anti-stall means connected in fluid communication with said motor means through said pressure controller means for decreasing the pressure to which said motor means is exposed in response to the occurrence of an impending overloading of the prime mover, means for providing a first signal which varies with variations in the operating speed of the prime mover, means for providing a second signal which varies with variations in the setting of a throttle for the prime mover, and means for providing a third signal which varies as a function of variations in the displacement of the hydrostatic unit, said anti-stall means including means responsive to said first, second and third signals for reducing the control fluid pressure to which said motor means is exposed upon the occurrence of an impending overloading of the prime mover.
Claim 35
Independent Claim
173 words
An apparatus for controlling the operation of a hydrostatic transmission driven by a prime mover and having a variable displacement hydrostatic unit, said apparatus comprising fluid motor means for varying the displacement of the hydrostatic unit in response to variations in control fluid pressure to which said motor means is exposed, pressure controller means operable to anyone of a plurality of settings to vary the control fluid pressure to which said motor means is exposed with variations in the setting of said pressure controller means, and anti-stall means connected in fluid communication with said motor means through said pressure controller means for decreasing the pressure to which said motor means is exposed in response to the occurrence of an impending overloading of the prime mover, said anti-stall means including means for maintaining the pressure of control fluid conducted to said pressure controller slightly above the control fluid pressure to which said motor means is exposed for all displacements of said hydrostatic unit in the absence of an impending overloading of the prime mover.
Claim 36
Independent Claim
173 words
An apparatus for controlling the operation of a hydrostatic transmission driven by a prime mover and having a variable displacement hydrostatic unit, said apparatus comprising fluid motor means for varying the displacement of the hydrostatic unit in response to variations in control fluid pressure to which said motor means is exposed, pressure controller means operable to anyone of a plurality of settings to vary the control fluid pressure to which said motor means is exposed with variations in the setting of said pressure controller means, and anti-stall means connected in fluid communication with said motor means through said pressure controller means for decreasing the pressure to which said motor means is exposed in response to the occurrence of an impending overloading of the prime mover, said anti-stall means including means for maintaining the pressure of control fluid conducted to said pressure controller slightly above the control fluid pressure to which said motor means is exposed for all displacements of said hydrostatic unit in the absence of an impending overloading of the prime mover.
Claim 37
Independent Claim
265 words
An apparatus for controlling the operation of a hydrostatic transmission driven by a prime mover and having a variable displacement hydrostatic unit, said apparatus comprising fluid motor means for varyin varying displacement of the hydrostatic unit in response to variations in control fluid pressure to which said motor means is exposed, pressure controller means operable to any one of a plurality of settings to vary the control fluid pressure to which said motor means is exposed with variations in the setting of said pressure controller means, and anti-stall means connected in fluid communication with said motor means through said pressure controller means for decreasing the pressure to which said motor means is exposed in response to the occurrence of an impending overloading of the prime mover, said pressure controller means including valve means for varying the control fluid pressure to which said motor means is exposed, said valve means being operable between a first condition varying the control fluid pressure to which said motor means is exposed and a second condition in which the control fluid pressure to which said motor means is exposed is maintained substantially constant, said apparatus further including fluid pressure feedback means for urging operation of said valve means from the first condition to the second condition under the influence of a fluid pressure force which varies as a function of variations in the control fluid pressure to which said motor means is exposed, and means for urging said valve means against operation to the second condition which a second force with corresponds to a setting of said pressure controller means.
Claim 38
Independent Claim
265 words
An apparatus for controlling the operation of a hydrostatic transmission driven by a prime mover and having a variable displacement hydrostatic unit, said apparatus comprising fluid motor means for varyin varying displacement of the hydrostatic unit in response to variations in control fluid pressure to which said motor means is exposed, pressure controller means operable to any one of a plurality of settings to vary the control fluid pressure to which said motor means is exposed with variations in the setting of said pressure controller means, and anti-stall means connected in fluid communication with said motor means through said pressure controller means for decreasing the pressure to which said motor means is exposed in response to the occurrence of an impending overloading of the prime mover, said pressure controller means including valve means for varying the control fluid pressure to which said motor means is exposed, said valve means being operable between a first condition varying the control fluid pressure to which said motor means is exposed and a second condition in which the control fluid pressure to which said motor means is exposed is maintained substantially constant, said apparatus further including fluid pressure feedback means for urging operation of said valve means from the first condition to the second condition under the influence of a fluid pressure force which varies as a function of variations in the control fluid pressure to which said motor means is exposed, and means for urging said valve means against operation to the second condition which a second force with corresponds to a setting of said pressure controller means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-07 | 1977-07-09 | 1978-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-07 | 1981-07-09 | 1982-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-07 | 1985-07-09 | 1986-01-08 | $7700.00 | Window Closed / Lapsed |