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US4487085A Expired / Lapsed US ⏱️ 0.0 years remaining

Infinitely variable gear ratio transmission

Assignee: VARITRANS INTERNATIONAL Corp 5109 E LA PALMA SUITE C ANAHEIM CALIFORNIA 92807 A CA CORP
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Filing: 1980-12-29
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Granted: 1984-12-11
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Expires: 2000-12-29
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Abstract

Abstract An infinitely variable gear ratio transmission includes plural cam followers driven to oscillate by a rotating cam. The oscillatory motion of the cam followers is combined through plural clutches to provide an output drive. The cam includes at least one surface formed to rotate the cam followers at a constant velocity when the cam rotates at a constant velocity, thereby permitting the output drive to be smooth. The cam is tapered from one end to the other to permit the gear ratio of the transmission to be varied in infinite increments by adjusting the position of the cam relative to the followers. Means for manually or automatically adjusting the gear ratio is provided. Increased gear ratios may be obtained by separating the physical location of the follower mounting shaft from the rotational axis of the follower arms. A universal joint, formed to uniformly transmit rotational velocity, is included to connect the inclined follower shafts to the output drive. The follower arms are oriented relative to the cam such that the chords of follower movement during contact of the follower with the constant velocity surface, at various gear ratios, are mutually parallel, and the chord of such follower movement at the highest gear ratio passes through the center of rotation of the cam. An alternative embodiment of the present invention further includes cooperating clutches which permit transmission of unidirectional shaft rotation between an input shaft and an output shaft regardless of the direction of torque applied to the shafts.

Inventors

  • 👤 Clifford H. Collins

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 23:29
CPC Classifications
F; F16; F16H; F16H29/00; F16H29/02; F16H29/04; Y; Y10; Y10T; Y10T74/00; Y10T74/15; Y10T74/1503; Y10T74/1505; Y10T74/1508; Y10T74/151; Y10T74/1524

Claims Analysis

Total Claims: 64
Claim 1
Independent Claim 188 words
A mechanical transmission, comprising: a cam having at lest one lobe, said lobe tapered in the direction of the axis of said cam to provide a cam lift which changes along the axis of said cam; plural cam followers, each mounted on a shaft which straddles said cam, said shaft mounted on a pair of bearings at opposite ends of said cam, said bearings providing a rotational axis for said followers, said followers each including a follower arm contacting said cam; input drive means for relatively rotating said cam and said rotational axes of each follower; said rotational axis intercepting the rotational path of said cam lobe; means for combining the oscillation of said plural followers to provide an output drive; said cam and said followers formed and relatively positioned to provide constant velocity output drive at said combining means when said input drive means has constant velocity; and means for relatively adjusting the location of said plural cam followers along said axis of said cam to change the location of contact between said follower arms and said cam and thereby adjust the gear ratio of said transmission.
Claim 2
Dependent Claim 188 words
A mechanical transmission, comprising: a cam having at lest one lobe, said lobe tapered in the direction of the axis of said cam to provide a cam lift which changes along the axis of said cam; plural cam followers, each mounted on a shaft which straddles said cam, said shaft mounted on a pair of bearings at opposite ends of said cam, said bearings providing a rotational axis for said followers, said followers each including a follower arm contacting said cam; input drive means for relatively rotating said cam and said rotational axes of each follower; said rotational axis intercepting the rotational path of said cam lobe; means for combining the oscillation of said plural followers to provide an output drive; said cam and said followers formed and relatively positioned to provide constant velocity output drive at said combining means when said input drive means has constant velocity; and means for relatively adjusting the location of said plural cam followers along said axis of said cam to change the location of contact between said follower arms and said cam and thereby adjust the gear ratio of said transmission.
Claim 3
Dependent Claim 34 words
A mechanical transmission, as defined in claim 1, wherein said gear ratio is neutral when the location of said contact between the follower arms and said cam is at one end of said cam.
Claim 4
Dependent Claim 27 words
A mechanical transmission, as defined in claim 1, wherein said means for relatively adjusting automatically adjusts said location in response to the torque supplied to said transmission.
Claim 5
Dependent Claim 19 words
A mechanical transmission, as defined in claim 1, wherein said relatively adjusting means permits manual adjustment of said location.
Claim 6
Dependent Claim 35 words
A mechanical transmission, as defined in claim 1, wherein said tapered cam lobe provides constant velocity output drive at said combining means at all transmission gear ratios when said input drive means has constant velocity.
Claim 7
Dependent Claim 45 words
A mechanical transmission, as defined in claim 1, wherein said combining means comprises: a housing mounting said pair of bearings in a fixed position; an output shaft mounted for rotation on said housing; and plural clutches connecting said plural cam followers to said output shaft.
Claim 8
Dependent Claim 50 words
A mechanical transmission, as defined in claim 1, wherein said cam lobe has a constant velocity lift profile through a rotational segment of said cam which is greater than 360 degrees divided by the product of the number of said plural followers and the number of lobes on said cam.
Claim 9
Dependent Claim 14 words
A mechanical transmission, as defined in claim 1, wherein said cam has plural lobes.
Claim 10
Dependent Claim 106 words
A mechanical transmission, comprising: a cam having at least one lobe; plural cam followers, each mounted for oscillation about a rotational axis, said followers each including a follower arm contacting said cam, said plural cam followers each mounted on a physical axis which is inclined relative said rotational axis; input drive means for relatively rotating said cam and said follower axis of each follower; means for combining the oscillation of said plural followers to provide an output drive; and said cam and said followers formed and relatively positioned to provide constant velocity output drive at said combining means when said input drive means has constant velocity.
Claim 11
Dependent Claim 106 words
A mechanical transmission, comprising: a cam having at least one lobe; plural cam followers, each mounted for oscillation about a rotational axis, said followers each including a follower arm contacting said cam, said plural cam followers each mounted on a physical axis which is inclined relative said rotational axis; input drive means for relatively rotating said cam and said follower axis of each follower; means for combining the oscillation of said plural followers to provide an output drive; and said cam and said followers formed and relatively positioned to provide constant velocity output drive at said combining means when said input drive means has constant velocity.
Claim 12
Dependent Claim 18 words
A mechanical transmission, as defined in claim 9, wherein said combining means comprises a constant velocity universal joint.
Claim 13
Dependent Claim 95 words
A variable gear ratio transmission comprising: an input shaft; an output shaft; a cam driven by said input shaft; plural crank shafts each rotationally mounted on opposite sides of said cam and each rotating about a shaft rotational axis which intercepts the path of said cam; plural cam follows, one of said followers mounted on each of said crank shafts, driven by said cam, and driving said output shaft; and means for adjusting the relative positions of said cam and said plural cam followers to adjust in infinite increments the gear ratio of said transmission.
Claim 14
Dependent Claim 95 words
A variable gear ratio transmission comprising: an input shaft; an output shaft; a cam driven by said input shaft; plural crank shafts each rotationally mounted on opposite sides of said cam and each rotating about a shaft rotational axis which intercepts the path of said cam; plural cam follows, one of said followers mounted on each of said crank shafts, driven by said cam, and driving said output shaft; and means for adjusting the relative positions of said cam and said plural cam followers to adjust in infinite increments the gear ratio of said transmission.
Claim 15
Dependent Claim 33 words
A variable gear ratio transmission, as defined in claim 11, wherein said cam includes at least one lobe having an acceleration surface followed by a constant velocity surface followed by a deceleration surface.
Claim 16
Dependent Claim 34 words
A variable gear ratio transmission, as defined in claim 11, wherein said constant velocity rotation of said output shaft is provided by overlapping constant velocity rotational segments of each of said plural cam followers.
Claim 17
Dependent Claim 36 words
A variable gear ratio transmission, as defined in claim 11, wherein said adjusting means automatically adjusts the relative positions of said cam and said plural cam followers in response to the torque applied to said transmission.
Claim 18
Dependent Claim 35 words
A variable gear ratio transmission, as defined in claim 14, wherein said adjusting means comprises a biasing means biasing said transmission toward higher gear ratios, said biasing means opposed by torque applied to said transmission.
Claim 19
Dependent Claim 22 words
A variable gear ratio transmission, as defined in claim 11, wherein said adjusting means permits manual adjustment of said transmission gear ratio.
Claim 20
Dependent Claim 36 words
A variable gear ratio transmission, as defined in claim 11, wherein said adjusting means adjusts the relative positions of said cam and said plural cam followers in a direction parallel to the axis of said cam.
Claim 21
Dependent Claim 18 words
A variable gear ratio transmission, as defined in claim 11, wherein said cam is shaped as an involute.
Claim 22
Dependent Claim 39 words
A variable gear ratio transmission, as defined in claim 11, additionally comprising: plural one-way clutches connecting said plural cam followers to said output shaft, said clutches combining the movement of said plural cam followers to drive said output shaft.
Claim 23
Dependent Claim 115 words
A variable gear ratio transmission, comprising: an input shaft; an output shaft; a cam driven by said input shaft; said cam including at least one lobe having an acceleration surface followed by a constant velocity surface followed by a deceleration surface, the rate of acceleration provided by said acceleration surface being constant; plural cam followers driven by said cam and driving said output shaft; means for adjusting the relative positions of said cam and said plural cam followers to adjust in infinite increments the gear ratio of said transmission; and said cam and plural followers shaped and positioned to provide constant velocity rotation of said output shaft when said input shaft rotates at constant velocity.
Claim 24
Dependent Claim 115 words
A variable gear ratio transmission, comprising: an input shaft; an output shaft; a cam driven by said input shaft; said cam including at least one lobe having an acceleration surface followed by a constant velocity surface followed by a deceleration surface, the rate of acceleration provided by said acceleration surface being constant; plural cam followers driven by said cam and driving said output shaft; means for adjusting the relative positions of said cam and said plural cam followers to adjust in infinite increments the gear ratio of said transmission; and said cam and plural followers shaped and positioned to provide constant velocity rotation of said output shaft when said input shaft rotates at constant velocity.
Claim 25
Dependent Claim 22 words
A variable gear ratio transmission, as defined in claim 20, wherein the rate of deceleration provided by said deceleration surface is constant.
Claim 26
Dependent Claim 164 words
A variable gear ratio transmission, comprising: an input shaft; an output shaft; a cam driven by said input shaft; plural cam followers driven by said cam and driving said output shaft; means for adjusting the relative positions of said cam and said plural cam followers to adjust in infinite increments the gear ratio of said transmission; said cam and plural followers shaped and positioned to provide constant velocity rotation of said output shaft when said input shaft rotates at constant velocity; a housing; plural gear segments, each of said gear segments having a radius and an axis, said axis being closer in the radial direction of said segment to said housing than said radius, said gear segments connected to be driven by said plural cam followers; plural one way clutches mounted on said output shaft connecting said plural gear segments to said output shaft, said clutches combining the movement of said plural gear segments to said plural gear segments to drive said output shaft.
Claim 27
Dependent Claim 164 words
A variable gear ratio transmission, comprising: an input shaft; an output shaft; a cam driven by said input shaft; plural cam followers driven by said cam and driving said output shaft; means for adjusting the relative positions of said cam and said plural cam followers to adjust in infinite increments the gear ratio of said transmission; said cam and plural followers shaped and positioned to provide constant velocity rotation of said output shaft when said input shaft rotates at constant velocity; a housing; plural gear segments, each of said gear segments having a radius and an axis, said axis being closer in the radial direction of said segment to said housing than said radius, said gear segments connected to be driven by said plural cam followers; plural one way clutches mounted on said output shaft connecting said plural gear segments to said output shaft, said clutches combining the movement of said plural gear segments to said plural gear segments to drive said output shaft.
Claim 28
Dependent Claim 42 words
A variable gear ratio transmission, as defined in claim 19, additionally comprising: wherein each of said plural cam followers comprises a follower shaft and a follower arm mounted on said follower shaft; and said clutches are mounted on said plural follower shafts.
Claim 29
Dependent Claim 113 words
A variable gear ratio transmission, comprising: a housing; a cam within said housing having at least one lobe; plural cam follower arms mounted on said housing at opposite ends of said cam to straddle said cam, to be oscillated by said cam as said cam rotates and to thus provide the output drive for said transmission; means for relatively rotating said cam and said housing to provide the input drive for said transmission; and plural shafts mounting said plural cam follower arms, said cam lobe rotating through the rotational axes of said cam follower arms, but not through the physical locations of said plural shafts, to increase the gear ratio of said transmission.
Claim 30
Dependent Claim 113 words
A variable gear ratio transmission, comprising: a housing; a cam within said housing having at least one lobe; plural cam follower arms mounted on said housing at opposite ends of said cam to straddle said cam, to be oscillated by said cam as said cam rotates and to thus provide the output drive for said transmission; means for relatively rotating said cam and said housing to provide the input drive for said transmission; and plural shafts mounting said plural cam follower arms, said cam lobe rotating through the rotational axes of said cam follower arms, but not through the physical locations of said plural shafts, to increase the gear ratio of said transmission.
Claim 31
Dependent Claim 37 words
A variable gear ratio transmission, as defined in claim 24, wherein said plural shafts mounting said plural cam follower arms are offset at both of their respective ends relative said rotational axes of said cam follower arms.
Claim 32
Dependent Claim 38 words
A variable gear ratio transmission, as defined in claim 24, wherein said cam includes a driving surface which provides constant velocity rotation of said follower arms about said rotational axes when said cam is driven at constant velocity.
Claim 33
Dependent Claim 29 words
A variable gear ratio transmission, as defined in claim 24, additionally comprising: means combining the oscillation of said plural follower arms to provide a smooth output for said transmission.
Claim 34
Dependent Claim 100 words
A variable gear ratio transmission, comprising: a cam providing the input drive for said transmission, said cam having at least one lobe; plural cam follower arms mounted to be oscillated by said cam as said cam rotates and to thus provide the output drive for said transmission; and plural shafts mounting said plural cam follower arms, said cam lobe rotating through the rotational axes of said cam follower arms, but not through the physical locations of said plural shafts, to increase the gear ratio of said transmission, said plural shafts inclined relative and rotational axes of said cam follower arms.
Claim 35
Dependent Claim 100 words
A variable gear ratio transmission, comprising: a cam providing the input drive for said transmission, said cam having at least one lobe; plural cam follower arms mounted to be oscillated by said cam as said cam rotates and to thus provide the output drive for said transmission; and plural shafts mounting said plural cam follower arms, said cam lobe rotating through the rotational axes of said cam follower arms, but not through the physical locations of said plural shafts, to increase the gear ratio of said transmission, said plural shafts inclined relative and rotational axes of said cam follower arms.
Claim 36
Dependent Claim 32 words
A variable gear ratio transmission, as defined in claim 28, additionally comprising: plural U-joints connecting said plural shafts mounting said plural cam follower arms to provide the output drive for said transmission.
Claim 37
Dependent Claim 74 words
A variable gear ratio transmission, comprising: an input shaft; a cam; plural cam followers driven by said cam; an output shaft; means for providing a first operational mode by connecting said input shaft to drive said cam and connecting said plural followers to drive said output shaft; and means for providing a second operational mode by connecting said output shaft to drive said cam and connecting said plural followers to drive said input shaft.
Claim 38
Dependent Claim 74 words
A variable gear ratio transmission, comprising: an input shaft; a cam; plural cam followers driven by said cam; an output shaft; means for providing a first operational mode by connecting said input shaft to drive said cam and connecting said plural followers to drive said output shaft; and means for providing a second operational mode by connecting said output shaft to drive said cam and connecting said plural followers to drive said input shaft.
Claim 39
Dependent Claim 27 words
A variable gear ratio transmission, as defined in claim 30, wherein said first and second operational modes each provide rotation of said cam in the same direction.
Claim 40
Dependent Claim 33 words
A variable gear ratio transmission, as defined in claim 30, additionally comprising: means connecting said input shaft to an automobile engine; and means connecting said output shaft to the wheels of said automobile.
Claim 41
Dependent Claim 64 words
A variable gear ratio transmission, as defined in claim 30, wherein said cam comprises lobes which are tapered in a direction parallel to the axis of said cam, said transmission additionally comprising: means for varying the relative position of said plural cam followers and said cam in a direction parallel to the axis of said cam to vary the gear ratio of said transmission.
Claim 42
Dependent Claim 40 words
A variable gear ratio transmission, as defined in claim 33, wherein said means for adjusting responds automatically to the torque applied to said transmission to permit a variable speed at said output shaft with constant speed at said input shaft.
Claim 43
Dependent Claim 37 words
A variable gear ratio transmission, as defined in claim 30, additionally comprising: means for automatically changing from said first operational mode to said second operational mode in response to the direction of torque applied to said transmission.
Claim 44
Dependent Claim 36 words
A variable gear ratio transmission, as defined in claim 30, wherein said means for providing a first operational mode comprises clutches connecting said cam to said input shaft and disconnecting said cam from said output shaft.
Claim 45
Dependent Claim 37 words
A variable gear ratio transmission, as defined in claim 30, wherein said means for providing said second operational mode comprises clutches for connecting said output shaft to said cam and disconnecting said input shaft from said cam.
Claim 46
Dependent Claim 39 words
A variable gear ratio transmission, as defined in claim 37, wherein said means for providing a second operational mode further comprises: clutches connecting said plural followers to said input shaft and disconnecting said plural followers from said output shaft.
Claim 47
Dependent Claim 40 words
A variable gear ratio transmission, as defined in claim 30, wherein said cam and said plural cam followers are formed and relatively positioned to provide a constant velocity transmission output when the input to said transmission is at constant velocity.
Claim 48
Dependent Claim 49 words
A variable gear ratio transmission, as defined in claim 30, wherein said plural cam followers comprise: plural shafts mounting plural follower arms for rotation about said plural follower arm rotational axes, the respective physical axes of said shafts each offset from the rotational axes of their respective follower arms.
Claim 49
Dependent Claim 114 words
A variable speed transmission, comprising: a cam, providing the input drive for said transmission; plural cam follower arms oscillated at constant velocity by said cam to provide the output drive for said transmission; a cam roller, mounted for rotation about a roller axis on each said cam follower arm, and contacting said cam; and said roller axis of each of said follower arms moving in a respective arcuate path when said cam drives said followers at constant velocity to provide the output drive for said transmission, the chord connecting the ends of each said arcuate path passing through the axis of rotation of said cam when said transmission is at its highest gear ratio.
Claim 50
Dependent Claim 114 words
A variable speed transmission, comprising: a cam, providing the input drive for said transmission; plural cam follower arms oscillated at constant velocity by said cam to provide the output drive for said transmission; a cam roller, mounted for rotation about a roller axis on each said cam follower arm, and contacting said cam; and said roller axis of each of said follower arms moving in a respective arcuate path when said cam drives said followers at constant velocity to provide the output drive for said transmission, the chord connecting the ends of each said arcuate path passing through the axis of rotation of said cam when said transmission is at its highest gear ratio.
Claim 51
Dependent Claim 114 words
A variable speed transmission, as defined in claim 41, wherein said cam has lobes, tapered in a direction parallel to the axis of said cam, said transmission additionally comprising: means for varying the relative position of said plural cam followers and said cam in a direction parallel to the axis of said cam to provide various gear ratios for said transmission, said respective arcuate paths of each of said followers varying according to said various gear ratios; and said plural follower arms oriented relative to said cam to permit the chords defined by the ends of said varying arcuate paths of one of said followers at said various gear ratios to be mutually parallel.
Claim 52
Dependent Claim 26 words
A variable speed transmission, as defined in claim 41, wherein said cam may be rotated in either direction about its axis to oscillate said plural followers.
Claim 53
Dependent Claim 44 words
A variable speed transmission, as defined in claim 41, additionally comprising: plural shafts mounting said plural cam follower arms for rotation about plural cam follower arm rotational axes, said cam positioned so that the lobe of said cam rotates through said plural rotational axes.
Claim 54
Dependent Claim 83 words
A transmission having a cam and plural cam followers, wherein the cam is tapered to provide varying lift rates as its position relative the followers is adjusted, said followers providing the output drive for said transmission through one-way clutches driving a common output shaft, wherein the improvement comprises: a driving surface on said cam which is shaped to provide constant velocity rotation of said output shaft when said cam is rotated at constant velocity regardless of the direction of rotation of said cam.
Claim 55
Dependent Claim 83 words
A transmission having a cam and plural cam followers, wherein the cam is tapered to provide varying lift rates as its position relative the followers is adjusted, said followers providing the output drive for said transmission through one-way clutches driving a common output shaft, wherein the improvement comprises: a driving surface on said cam which is shaped to provide constant velocity rotation of said output shaft when said cam is rotated at constant velocity regardless of the direction of rotation of said cam.
Claim 56
Dependent Claim 53 words
A transmission, as defined in claim 45, wherein said cam is tapered in a direction parallel to the rotational axis of said cam to provide a variable gear ratio for said transmission, said cam providing said driving surface shaped to provide constant velocity rotation at all points along the taper of said cam.
Claim 57
Dependent Claim 42 words
A transmission, as defined in claim 46, additionally comprising: means for adjusting the relative position of said cam and said plural cam followers in a direction parallel to the rotational axis of said cam to adjust the gear ratio of said transmission.
Claim 58
Dependent Claim 23 words
A transmission, as defined in claim 47, wherein said means for adjusting operates automatically in response to the torque applied to said transmission.
Claim 59
Dependent Claim 13 words
A transmission, as defined in claim 47, wherein said adjusting means is manual.
Claim 60
Dependent Claim 74 words
A transmission, comprising: a cam, driven by an input shaft, including a driving cam surface including: (a) a constant acceleration surface; (b) a constant velocity surface; and (c) a constant deceleration surface; plural followers driven to oscillate by said cam, said followers rotating at a uniform velocity when contacting said constant velocity surface and when said cam is rotated at constant velocity; and means connecting said plural followers to drive an output transmission shaft.
Claim 61
Dependent Claim 74 words
A transmission, comprising: a cam, driven by an input shaft, including a driving cam surface including: (a) a constant acceleration surface; (b) a constant velocity surface; and (c) a constant deceleration surface; plural followers driven to oscillate by said cam, said followers rotating at a uniform velocity when contacting said constant velocity surface and when said cam is rotated at constant velocity; and means connecting said plural followers to drive an output transmission shaft.
Claim 62
Dependent Claim 38 words
A transmission, as defined in claim 50, wherein said means connecting said plural followers comprises plural one-way clutches which combine said uniform velocity of said plural followers to provide a smooth output drive for said output transmission shaft.
Claim 63
Dependent Claim 166 words
A variable gear ratio transmission, comprising: a housing; a cam having at least one lobe, said lobe tapered in the direction of the axis of said cam to provide a cam lift which changes along the axis of said cam; plural cam followers, each mounted for oscillation about a rotational axis, said followers each including a follower arm contacting said cam; input drive means for relatively rotating said cam and said rotational axis of each follower; and means for combining the oscillation to said plural followers to provide an output drive, said means comprising: plural gear segments, each of said gear segments having a radius and an axis, said axis being closer in the radial direction of said gear segment, to said housing than said radius, said gear segments each mounted to rotate with one of said followers; a shaft; plural one-way clutches mounted on said shaft; and a gear mounted on each of said clutches, each said gear meshing with one of said gear segments.
Claim 64
Dependent Claim 166 words
A variable gear ratio transmission, comprising: a housing; a cam having at least one lobe, said lobe tapered in the direction of the axis of said cam to provide a cam lift which changes along the axis of said cam; plural cam followers, each mounted for oscillation about a rotational axis, said followers each including a follower arm contacting said cam; input drive means for relatively rotating said cam and said rotational axis of each follower; and means for combining the oscillation to said plural followers to provide an output drive, said means comprising: plural gear segments, each of said gear segments having a radius and an axis, said axis being closer in the radial direction of said gear segment, to said housing than said radius, said gear segments each mounted to rotate with one of said followers; a shaft; plural one-way clutches mounted on said shaft; and a gear mounted on each of said clutches, each said gear meshing with one of said gear segments.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-12-11 1988-06-11 1988-12-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-12-11 1992-06-11 1992-12-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-12-11 1996-06-11 1996-12-11 $7700.00 Window Closed / Lapsed

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