Patent US3815442A successfully refreshed from Google Patents.
US3815442A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential mechanism
Assignee: Borg Warner Corp
•
Filing: 1958-10-27
•
Granted: 1974-06-11
•
Expires: 1978-10-27
Abstract
Abstract 1. In a differential mechanism the combination comprising a hollow casing adapted to be rotated, a plurality of pinion gears rotatably and revolably mounted in said casing, said casing having means defining a pair of openings, an output shaft received in each of said openings, a side gear affixed on the inner end of each of said shafts for limited axial movement with respect thereto, each of said gears being in mesh with said pinions and normally driven thereby at equal speed, at least one of said side gears and at least one of said pinion gears having positive pressure angle teeth, said gears being normally relatively fixed with respect to said pinions and being relatively movable with respect thereto to afford differentiation, said casing having a splined bore adjacent the inner end of each of said output shafts, each of said side gears being formed with an axially outwardly extending externally splined hub, a disc pack received in each of said bores and being operatively connected to the splines of each of said bores and the splines of each of said hubs, each of said disc packs being disposed radially outwardly of the area of mesh of said pinion gears and said side gears, and Belleville washer means extending between said casing and each of said disc packs for effecting a first axial thrust to urge said side gears into mesh with said pinion gears, said pinion gears and said side gears being additionally characterized as being meshed in a relationship such that when torque is applied to said hollow casing said pinion gears and said side gears provide a second axial thrust against said disc pack in a direction opposite the direction of said first axial thrust substantially uniform peripheral. This invention relates to differential mechanisms and more particularly to a differential mechanism in which differentiation is retarded.
Inventors
- 👤 Aninch H Mc
- 👤 S Mieras
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:21
CPC Classifications
F; F16; F16H; F16H48/00; F16H48/20; F16H48/22; F16H48/06; F16H48/08; F16H2048/085; F16H48/38; F16H48/40
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
291 words
In a differential mechanism the combination comprising a hollow casing adapted to be rotated, a plurality of pinion gears rotatably and revolably mounted in said casing, said casing having means defining a pair of openings, an output shaft received in each of said openings, a side gear affixed on the inner end of each of said shafts for limited axial movement with respect thereto, each of said gears being in mesh with said pinions and normally driven thereby at equal speed, at least one of said side gears and at least one of said pinion gears having positive pressure angle teeth, said gears being normally relatively fixed with respect to said pinions and being relatively movable with respect thereto to afford differentiation, said casing having a splined bore adjacent the inner end of each of said output shafts, each of said side gears being formed with an axially outwardly extending externally splined hub, a disc pack received in each of said bores and being operatively connected to the splines of each of said bores and the splines of each of said hubs, each of said disc packs being disposed radially outwardly of the area of mesh of said pinion gears and said side gears, and Belleville washer means extending between said casing and each of said disc packs for effecting a first axial thrust to urge said side gears into mesh with said pinion gears, said pinion gears and said side gears being additionally characterized as being meshed in a relationship such that when torque is applied to said hollow casing said pinion gears and said side gears provide a second axial thrust against said disc pack in a direction opposite the direction of said first axial thrust substantially uniform peripheral.
Claim 2
Dependent Claim
291 words
In a differential mechanism the combination comprising a hollow casing adapted to be rotated, a plurality of pinion gears rotatably and revolably mounted in said casing, said casing having means defining a pair of openings, an output shaft received in each of said openings, a side gear affixed on the inner end of each of said shafts for limited axial movement with respect thereto, each of said gears being in mesh with said pinions and normally driven thereby at equal speed, at least one of said side gears and at least one of said pinion gears having positive pressure angle teeth, said gears being normally relatively fixed with respect to said pinions and being relatively movable with respect thereto to afford differentiation, said casing having a splined bore adjacent the inner end of each of said output shafts, each of said side gears being formed with an axially outwardly extending externally splined hub, a disc pack received in each of said bores and being operatively connected to the splines of each of said bores and the splines of each of said hubs, each of said disc packs being disposed radially outwardly of the area of mesh of said pinion gears and said side gears, and Belleville washer means extending between said casing and each of said disc packs for effecting a first axial thrust to urge said side gears into mesh with said pinion gears, said pinion gears and said side gears being additionally characterized as being meshed in a relationship such that when torque is applied to said hollow casing said pinion gears and said side gears provide a second axial thrust against said disc pack in a direction opposite the direction of said first axial thrust substantially uniform peripheral.
Claim 3
Dependent Claim
184 words
In a differential transmission unit, the combination comprising a casing, differential side gears mounted in the casing, compensating pinion gears between the side gears, the side gears being shiftable axially during relative rotation of the side gears and pinion gears, said side gears being provided with integral hubs having external gear teeth thereon, internal gear teeth on said casing concentric with said hub gear teeth, interleaved plates between each of said differential side gears and the opposing face of the casing, one set of plates having peripheral gear teeth interlocked with said casing gear teeth and the other set having internal gear teeth interlocked with the hub gear teeth, and a spring washer disposed about said hub and engaging said casing, said spring washer providing a substantially uniform peripheral axial force to bias said interleaved plates against said differential side gears thereby providing a retarding effect on the compensating action of the differential, said differential side gears moving axially outwardly upon increasing torque input to the differential to compress the interleaved plates against the opposed faces of the casing thereby increasing the retarding effect.
Claim 4
Dependent Claim
184 words
In a differential transmission unit, the combination comprising a casing, differential side gears mounted in the casing, compensating pinion gears between the side gears, the side gears being shiftable axially during relative rotation of the side gears and pinion gears, said side gears being provided with integral hubs having external gear teeth thereon, internal gear teeth on said casing concentric with said hub gear teeth, interleaved plates between each of said differential side gears and the opposing face of the casing, one set of plates having peripheral gear teeth interlocked with said casing gear teeth and the other set having internal gear teeth interlocked with the hub gear teeth, and a spring washer disposed about said hub and engaging said casing, said spring washer providing a substantially uniform peripheral axial force to bias said interleaved plates against said differential side gears thereby providing a retarding effect on the compensating action of the differential, said differential side gears moving axially outwardly upon increasing torque input to the differential to compress the interleaved plates against the opposed faces of the casing thereby increasing the retarding effect.
Claim 5
Dependent Claim
89 words
said pressure plate being mounted for axial movement relative to and unitary rotative movement with said gear case, d. and resilient means operatively connected to said clutch means and independent of said side gear for loading said pressure plate of said clutch means, e. the gears of said gear train being meshed in a relationship to provide a component of tooth pressure for urging at least one of said side gears axially outward to increase the loading of said clutch means in proportion to input torque to the transmission.
Claim 6
Dependent Claim
89 words
said pressure plate being mounted for axial movement relative to and unitary rotative movement with said gear case, d. and resilient means operatively connected to said clutch means and independent of said side gear for loading said pressure plate of said clutch means, e. the gears of said gear train being meshed in a relationship to provide a component of tooth pressure for urging at least one of said side gears axially outward to increase the loading of said clutch means in proportion to input torque to the transmission.
Claim 7
Dependent Claim
135 words
In a differential transmission unit, the combination comprising a rotatable gear case, a power transmission gear train operatively positioned within said case, clutch means operatively disposed between said gear train and said gear case for opposing relative rotary movement of the members of said gear train, a resilient washer engaging said clutch means and imparting a substantially uniform peripheral initial biasing effect thereto, at least some of the gears of said gear train having positive pressure angle teeth and at least one of the said gears having positive pressure angle teeth being movable in an outward direction, whereby upon the transfer of torque by said gear train the movable gear is urged outwardly to further engage said clutch means thereby resulting in greater opposition to the relative rotary movement of members of said gear train.
Claim 8
Dependent Claim
135 words
In a differential transmission unit, the combination comprising a rotatable gear case, a power transmission gear train operatively positioned within said case, clutch means operatively disposed between said gear train and said gear case for opposing relative rotary movement of the members of said gear train, a resilient washer engaging said clutch means and imparting a substantially uniform peripheral initial biasing effect thereto, at least some of the gears of said gear train having positive pressure angle teeth and at least one of the said gears having positive pressure angle teeth being movable in an outward direction, whereby upon the transfer of torque by said gear train the movable gear is urged outwardly to further engage said clutch means thereby resulting in greater opposition to the relative rotary movement of members of said gear train.
Claim 9
Dependent Claim
153 words
In a differential transmission unit the combination comprising, a rotatable gear case, a power transmission gear train operatively positioned within said case, said gear train including a pair of oppositely disposed differential gears adapted for receiving axle shafts, axially shiftable clutch plates positioned in said case, some of which are rotatable with said case and others which are rotatable with said differential gears, and a spring washer in said case acting to shift said plate axially relative to said case for providing a substantially uniform peripheral force to bias said clutch plates into engagement, at least some of said gears of said gear train having positive pressure angle teeth and at least one of said differential gears being axially shiftable, whereby upon the transmission of torque by said gear train, said axially shiftable differential gear is urged axially outward in proportion to the input torque, thereby further biasing said clutch plates into engagement.
Claim 10
Dependent Claim
153 words
In a differential transmission unit the combination comprising, a rotatable gear case, a power transmission gear train operatively positioned within said case, said gear train including a pair of oppositely disposed differential gears adapted for receiving axle shafts, axially shiftable clutch plates positioned in said case, some of which are rotatable with said case and others which are rotatable with said differential gears, and a spring washer in said case acting to shift said plate axially relative to said case for providing a substantially uniform peripheral force to bias said clutch plates into engagement, at least some of said gears of said gear train having positive pressure angle teeth and at least one of said differential gears being axially shiftable, whereby upon the transmission of torque by said gear train, said axially shiftable differential gear is urged axially outward in proportion to the input torque, thereby further biasing said clutch plates into engagement.
Claim 11
Dependent Claim
216 words
In a differential transmission unit, the combination comprising a rotatable gear case, a power transmission gear train operatively positioned within said case, said gear train including a spider, a plurality of pinion gears rotatably mounted on the legs of said spider, a pair of oppositely disposed differential gears meshing with said pinion gears, at least one of said differential gears being axially shiftable, a plurality of interleaved friction plates disposed between said shiftable differential gear and the opposed surface of said gear case for opposing relative rotary movement of members of said gear train, some of said plurality of interleaved friction plates being rotatable with and axially movable relative to said case and the remainder of said plurality of interleaved friction plates being rotatable with and axially movable relative to said shiftable differential gear, and resilient means compressed between the interleaved friction plates and the opposed surface of said case for providing a substantially uniform peripheral axial force to bias said interleaved plates against said shiftable differential gear, thereby providing a retarding effect on the compensating action of the differential, at least some of the members of said gear train having positive pressure angled teeth, whereby said shiftable differential gear is shifted axially outwardly in response to input torque and further compresses said interleaved friction plates.
Claim 12
Dependent Claim
216 words
In a differential transmission unit, the combination comprising a rotatable gear case, a power transmission gear train operatively positioned within said case, said gear train including a spider, a plurality of pinion gears rotatably mounted on the legs of said spider, a pair of oppositely disposed differential gears meshing with said pinion gears, at least one of said differential gears being axially shiftable, a plurality of interleaved friction plates disposed between said shiftable differential gear and the opposed surface of said gear case for opposing relative rotary movement of members of said gear train, some of said plurality of interleaved friction plates being rotatable with and axially movable relative to said case and the remainder of said plurality of interleaved friction plates being rotatable with and axially movable relative to said shiftable differential gear, and resilient means compressed between the interleaved friction plates and the opposed surface of said case for providing a substantially uniform peripheral axial force to bias said interleaved plates against said shiftable differential gear, thereby providing a retarding effect on the compensating action of the differential, at least some of the members of said gear train having positive pressure angled teeth, whereby said shiftable differential gear is shifted axially outwardly in response to input torque and further compresses said interleaved friction plates.
Claim 13
Dependent Claim
126 words
In a differential transmission unit the combination comprising a. a gear case, b. a power transmission gear train operatively positioned within said case and driven thereby and including a pair of gears, c. clutch means operatively connected to said power transmission gear train and said case for opposing relative rotative movement of said gears of said gear train, e. and resilient means independent of said gear train and operatively connected to said clutch means for loading said clutch means, f. the gears of said gear train being meshed in a relationship to provide a component of tooth pressure for urging at least one gear of said gear train axially outward to increase the loading of said clutch means in proportion to input torque to the transmission.
Claim 14
Dependent Claim
126 words
In a differential transmission unit the combination comprising a. a gear case, b. a power transmission gear train operatively positioned within said case and driven thereby and including a pair of gears, c. clutch means operatively connected to said power transmission gear train and said case for opposing relative rotative movement of said gears of said gear train, e. and resilient means independent of said gear train and operatively connected to said clutch means for loading said clutch means, f. the gears of said gear train being meshed in a relationship to provide a component of tooth pressure for urging at least one gear of said gear train axially outward to increase the loading of said clutch means in proportion to input torque to the transmission.
Claim 15
Dependent Claim
23 words
In a differential transmission unit the combination comprising a. a gear case, b. a power transmission gear train operatively positioned within said case
Claim 16
Dependent Claim
23 words
In a differential transmission unit the combination comprising a. a gear case, b. a power transmission gear train operatively positioned within said case
Claim 17
Dependent Claim
23 words
In a differential transmission unit the combination comprising a. a gear case, b. a power transmission gear train drivenly positioned within said case
Claim 18
Dependent Claim
23 words
In a differential transmission unit the combination comprising a. a gear case, b. a power transmission gear train drivenly positioned within said case
Claim 19
Dependent Claim
23 words
In a differential transmission unit the combination comprising a. a gear case, b. a power transmission gear train drivenly positioned within said case
Claim 20
Dependent Claim
23 words
In a differential transmission unit the combination comprising a. a gear case, b. a power transmission gear train drivenly positioned within said case
Claim 21
Dependent Claim
22 words
In a differential transmission the combination comprising a. a gear case, b. a power transmission gear train operatively positioned within said case,
Claim 22
Dependent Claim
22 words
In a differential transmission the combination comprising a. a gear case, b. a power transmission gear train operatively positioned within said case,
Claim 23
Dependent Claim
24 words
In a differential transmission unit the combination comprising a. a gear case, b. a power transmission gear train drivenly positioned within said case and
Claim 24
Dependent Claim
24 words
In a differential transmission unit the combination comprising a. a gear case, b. a power transmission gear train drivenly positioned within said case and
Claim 25
Dependent Claim
23 words
In a differential transmission unit the combination comprising a. a gear case, b. a power transmission gear train drivenly positioned within said case
Claim 26
Dependent Claim
23 words
In a differential transmission unit the combination comprising a. a gear case, b. a power transmission gear train drivenly positioned within said case
Claim 27
Dependent Claim
23 words
In a differential transmission unit the combination comprising a. a gear case, b. a power transmission gear train drivenly positioned within said case
Claim 28
Dependent Claim
23 words
In a differential transmission unit the combination comprising a. a gear case, b. a power transmission gear train drivenly positioned within said case
Claim 29
Dependent Claim
293 words
In a drive transmission comprising driving and driven, relatively rotatable, coaxial members, a clutch mechanism adapted to drivingly connect said members comprising a first radially extending friction plate operatively connected to one of said members for rotation therewith, a second radially extending friction plate drivingly connected to the other of said members and arranged adjacent to said first friction plate, a pressure plate having a radially extending annular friction surface which is adjacent to one of said friction plates and engageable with a radially extending annular friction face formed on said one of said friction plates, said friction surface and said friction face being rotatable with respect to each other and at times urged against each other so as to define an area of frictional contact therebetween, means responsive to the torque input of said transmission for driving said friction surface and friction face towards each other with a force in accordance with the magnitude of said torque input so as to create a sliding frictional force over the entire area of said area of frictional contact, and additional means continually resiliently biasing said friction surface and friction face towards each other so as to apply a substantially constant force thereagainst in order to independently produce a second sliding frictional force against said entire area of said area of frictional contact, said additional means comprising a plurality of compression springs biasing said pressure plate into engagement with said one of said friction plates, said means responsive to the torque input of said transmission and said compression springs applying in parallel relationship to each other forces against said pressure plate in order to develop a cumulative sliding frictional force applied by said pressure plate against said entire area of said area of frictional contact.
Claim 30
Dependent Claim
293 words
In a drive transmission comprising driving and driven, relatively rotatable, coaxial members, a clutch mechanism adapted to drivingly connect said members comprising a first radially extending friction plate operatively connected to one of said members for rotation therewith, a second radially extending friction plate drivingly connected to the other of said members and arranged adjacent to said first friction plate, a pressure plate having a radially extending annular friction surface which is adjacent to one of said friction plates and engageable with a radially extending annular friction face formed on said one of said friction plates, said friction surface and said friction face being rotatable with respect to each other and at times urged against each other so as to define an area of frictional contact therebetween, means responsive to the torque input of said transmission for driving said friction surface and friction face towards each other with a force in accordance with the magnitude of said torque input so as to create a sliding frictional force over the entire area of said area of frictional contact, and additional means continually resiliently biasing said friction surface and friction face towards each other so as to apply a substantially constant force thereagainst in order to independently produce a second sliding frictional force against said entire area of said area of frictional contact, said additional means comprising a plurality of compression springs biasing said pressure plate into engagement with said one of said friction plates, said means responsive to the torque input of said transmission and said compression springs applying in parallel relationship to each other forces against said pressure plate in order to develop a cumulative sliding frictional force applied by said pressure plate against said entire area of said area of frictional contact.
Claim 31
Dependent Claim
155 words
A differential transmission unit comprising in combination, a rotatable gear case, a power transmission gear train operatively positioned within said case, clutch means operatively disposed between said gear train and said gear case for opposing relative rotation of the members of said gear train, said clutch means including a pair of friction surfaces at least one of which is associated with said gear train for rotation therewith and another of which is associated with said gear case for rotation therewith, and resilient means engaging said case and said clutch means with the bias thereof being independent of said gear train for causing engagement of said friction surfaces, the gears of said gear train being meshed in a relationship to provide a component of tooth pressure for urging at least one gear of said gear train axially outward to increase the force applied to said friction surfaces in proportion to the input torque to the transmission.
Claim 32
Dependent Claim
155 words
A differential transmission unit comprising in combination, a rotatable gear case, a power transmission gear train operatively positioned within said case, clutch means operatively disposed between said gear train and said gear case for opposing relative rotation of the members of said gear train, said clutch means including a pair of friction surfaces at least one of which is associated with said gear train for rotation therewith and another of which is associated with said gear case for rotation therewith, and resilient means engaging said case and said clutch means with the bias thereof being independent of said gear train for causing engagement of said friction surfaces, the gears of said gear train being meshed in a relationship to provide a component of tooth pressure for urging at least one gear of said gear train axially outward to increase the force applied to said friction surfaces in proportion to the input torque to the transmission.
Claim 33
Dependent Claim
216 words
In a differential transmission unit the combination comprising a rotatable gear case having opposed inner end faces, a power transmission gear train operatively positioned within said case and including a pair of compensating gears and a pair of side gears intermeshed therewith, a pair of abutment means carried by said case inward from said inner end faces thereof, clutch means operatively disposed between each of said abutment means and said inner end faces of said gear case for opposing relative rotative movement of the members of said gear train, said clutch means including a plurality of interleaved friction plates some of which are secured to said side gears for rotation therewith and others of which are secured to said gear case for rotation therewith, and spring means engaging said inner end faces of said case and said clutch means with the bias thereof being independent of said gear train and biasing said interleaved friction plates axially inwards against said abutment means, the pitch line of said side and compensating gears being disposed at an angle to utilize the axial thrust of the meshing teeth of said gears to urge said side gears axially outward to supplement said spring means and increase the force to said friction plates in proportion to the torque input to the transmission.
Claim 34
Dependent Claim
216 words
In a differential transmission unit the combination comprising a rotatable gear case having opposed inner end faces, a power transmission gear train operatively positioned within said case and including a pair of compensating gears and a pair of side gears intermeshed therewith, a pair of abutment means carried by said case inward from said inner end faces thereof, clutch means operatively disposed between each of said abutment means and said inner end faces of said gear case for opposing relative rotative movement of the members of said gear train, said clutch means including a plurality of interleaved friction plates some of which are secured to said side gears for rotation therewith and others of which are secured to said gear case for rotation therewith, and spring means engaging said inner end faces of said case and said clutch means with the bias thereof being independent of said gear train and biasing said interleaved friction plates axially inwards against said abutment means, the pitch line of said side and compensating gears being disposed at an angle to utilize the axial thrust of the meshing teeth of said gears to urge said side gears axially outward to supplement said spring means and increase the force to said friction plates in proportion to the torque input to the transmission.
Claim 35
Dependent Claim
292 words
In a differential transmission unit the combination comprising a rotatable gear case, a power transmission gear train operatively positioned within said case and including a pair of compensating gears and a pair of side gears intermeshed therewith, said side gears having a back face and said gear case having an inner end face means disposed in cooperating relationship with the back face of said side gear, circumferentially disposed abutment means carried by said case and positioned between said inner end face means and the plane of the back face of at least one of said side gears, a plurality of friction plates disposed between said abutment means and said inner end face means, some of said friction plates being operatively connected to said case for unitary rotation and axial movement relative thereto and the other of said friction plates being operatively connected to said one side gear for unitary rotation therewith and axial movement relative thereto, a spring washer reacting against one of said means and biasing at least some of said friction plates against the other of said means, said abutment means having an axial opening therethrough and at least a portion of said one side gear being movable axially outwardly through said opening, at least a portion of the back face of said side gear being operable to induce a biasing force on said friction plates, upon axial outward movement of said one side gear, the pitch line of said side and compensating gears being disposed at an angle to utilize the axial thrust of the meshing teeth of said gears to urge said one side gear outwardly to supplement said spring washer and increase the force to said friction plates in proportion to the torque input to the transmission.
Claim 36
Dependent Claim
292 words
In a differential transmission unit the combination comprising a rotatable gear case, a power transmission gear train operatively positioned within said case and including a pair of compensating gears and a pair of side gears intermeshed therewith, said side gears having a back face and said gear case having an inner end face means disposed in cooperating relationship with the back face of said side gear, circumferentially disposed abutment means carried by said case and positioned between said inner end face means and the plane of the back face of at least one of said side gears, a plurality of friction plates disposed between said abutment means and said inner end face means, some of said friction plates being operatively connected to said case for unitary rotation and axial movement relative thereto and the other of said friction plates being operatively connected to said one side gear for unitary rotation therewith and axial movement relative thereto, a spring washer reacting against one of said means and biasing at least some of said friction plates against the other of said means, said abutment means having an axial opening therethrough and at least a portion of said one side gear being movable axially outwardly through said opening, at least a portion of the back face of said side gear being operable to induce a biasing force on said friction plates, upon axial outward movement of said one side gear, the pitch line of said side and compensating gears being disposed at an angle to utilize the axial thrust of the meshing teeth of said gears to urge said one side gear outwardly to supplement said spring washer and increase the force to said friction plates in proportion to the torque input to the transmission.
Claim 37
Dependent Claim
150 words
In a differential transmission unit, the combination comprising a rotatable gear case, a power transmission gear train operatively positioned within said case, clutch means operatively disposed between said gear train and said gear case for opposing relative rotary movement of the members of said geAr train, a resilient spring means engaging said clutch means and imparting a substantially uniform peripheral initial biasing effect thereto, at least some of the gears of said gear train having positive pressure angle teeth and at least one of the said gears having positive pressure angle teeth being movable in an outward direction, whereby upon the transfer of torque by said gear train the movable gear is urged outwardly to further engage said clutch means thereby resulting in greater opposition to the relative rotary movement of members of said gear train, said resilient spring means urging the gears of said gear train toward meshing relation.
Claim 38
Dependent Claim
150 words
In a differential transmission unit, the combination comprising a rotatable gear case, a power transmission gear train operatively positioned within said case, clutch means operatively disposed between said gear train and said gear case for opposing relative rotary movement of the members of said geAr train, a resilient spring means engaging said clutch means and imparting a substantially uniform peripheral initial biasing effect thereto, at least some of the gears of said gear train having positive pressure angle teeth and at least one of the said gears having positive pressure angle teeth being movable in an outward direction, whereby upon the transfer of torque by said gear train the movable gear is urged outwardly to further engage said clutch means thereby resulting in greater opposition to the relative rotary movement of members of said gear train, said resilient spring means urging the gears of said gear train toward meshing relation.
References Cited (Backward Citations)
US1481889A
Cited
US1979414A
Cited
US2234591A
Cited
US2778246A
Cited
US2856048A
Cited
US2762240A
Cited
US2821096A
Cited
US2858920A
Cited
US2930256A
Cited
US2850922A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |