Abstract:
A compact transmission that is infinitely variable and load sensitive. It incorporates a standard hydrodynamic torque converter, however, this converter does not use a lock-up device. Instead engaged gears progressively change ratio output without shifting, thus eliminating the momentary power loss between shifts. It requires no special tooling and can be made from readily available over-the-counter parts. Thus, it is less expensive to manufacture than the transmissions and gearboxes currently used in modern vehicular and marine applications.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
   None. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to the field of transmissions and gearboxes for vehicular and marine applications, specifically to a load sensitive transmission that incorporates a standard hydrodynamic torque converter, however, this converter does not use a lock-up device. Instead engaged gears progressively change ratio output without shifting, thus eliminating the momentary power loss between shifts. In marine applications, the present invention can be used in lieu of controllable pitch propellers, with its park pawl as a shift brake. 
   2. Description of the Related Art 
   In modern vehicular applications, most transmissions incorporate a lock-up device for torque multiplication, and during shifts momentary power loss is experienced. Instead of using a lock-up device, the present invention uses engaged gears to progressively change ratio output without shifting until the vehicle has reached a maximum desired speed, thus providing a load sensitive transmission that does not require shifting during acceleration or deceleration, and therefore has no such momentary power loss. There are no geared transmissions known that have the same features and components as the present invention, nor all of its advantages. 
   BRIEF SUMMARY OF THE INVENTION—OBJECTIVES AND ADVANTAGES 
   The primary object of this invention is to provide a vehicle transmission having torque multiplication that uses engaged gears to progressively change ratio output without shifting, thus eliminating the momentary power loss between shifts that is commonly experienced by a majority of the transmissions used in modern vehicular applications. It is also an object of this invention to provide a vehicle transmission that is simpler in structure than other known transmissions. It is a further object of this invention to provide a vehicle transmission that is less expensive to manufacture than transmissions currently used in modern vehicular applications. It is also an object of this invention to provide a vehicle transmission that requires no special tooling and can be made from many readily available over-the-counter parts. 
   The present invention infinitely variable geared transmission eliminates the momentary power loss commonly experienced between shifts by progressively multiplying torque. An input shaft from an associated engine rotates the impeller end of the hydrodynamic torque converter, which is positioned adjacent to a stator and a turbine. As the torque converter rotates, oil is spun outward radially against turbine blades and causes the turbine to rotate. The rotating turbine then causes rotation of the inner primary shaft, the sun gear attached to the output end of the inner primary shaft, and the differential gears situated between the inner primary shaft and the output shaft. The turbine does not cause rotation of the output shaft. However, at this point the outer primary shaft is also turning at input/engine speed, being driven by the stator. The outer primary shaft rotates the clutch assembly and the oil pump, which supplies oil pressure for lubrication and pressure to activate the clutch pack. The oil pump also supplies oil pressure for movement of a gear reduction band associated with the planetary gear assembly and a reverse band associated with the beveled differential gears positioned downstream from the sun gear and planetary gear assembly, and maintains the proper oil capacity in the torque converter. When the stator adjacent to the torque converter is stalled by the discharge of oil in the torus trying to reverse its rotation, such reverse rotation is prevented by engagement of the gear reduction band associated with the planetary gear assembly. When applied, the gear reduction band stops rotation of the secondary primary shaft, causing the planetary gears positioned within the clearance groove in expanded downstream end of the second primary shaft to walk inside the internal gear at a speed slower than the sun gear, which is attached to the inner primary shaft and is turning at engine/input speed. Since the gear reduction band application also slows the carrier and the differential gears it contains, the gear reduction band causes the carrier to rotate at the same speed as the planetary gear assembly, which is less than the speed of the inner primary shaft and gives the present invention as a whole its first gear reduction. When the revolutions per minute are increased, the hydrodynamic conditions in the torque converter tend to approach the same speed around the torus inside the converter. This causes the outer primary shaft, the inner primary shaft, and the secondary primary shaft to run at slightly different rotational speeds. At this point, the gear reduction band is released and the clutch pack is engaged, letting the secondary primary shaft rotate at engine/input speed. Also at this point, the internal gear attached to the secondary primary shaft will be attached mechanically to the stator and the impeller. The turbine is not yet up to engine/input speed, since the hydrostatic lock-up in the torus has not occurred, allowing the inner primary shaft and the turbine to both turn at less than engine/input speed. The inner primary shaft will permit the differential gears and carrier to turn about its axis, thereby reducing the amount of rotational speed transmitted to the output shaft. However, the created speed differential causes an increase in the torque that is applied to the carrier. When the torque converter, stator, and turbine achieve a hydrostatic lock, the speed of the outer primary shaft, secondary primary shaft, and inner primary shaft are then running at the same speed, giving the unit a 1:1 lock-up from the inner primary shaft to the output shaft. This is where the clutch pack is activated to secure a mechanical lock-up to back up the hydrostatic lock between the inner primary shaft and the output shaft. When a hydrostatic lock-up occurs inside the torque converter, the oil spinning inside its torus comes to a stop and the oil is in a hydraulic lock centrifugally. The preferred parking system and governor of the present invention are available as standard Ford products, except for the pawl associated with the parking system, which is new. The reverse band secures a drum positioned between the differential gears and the parking system. When the reverse band is activated to engage the drum, the drum stops the rotation of the carrier, the inner primary shaft, and the output shaft, and then causes the output shaft to rotate in a reverse direction to that of the inner primary shaft. 
   While the description herein provides preferred embodiments of the present infinitely variable transmission, it should not be used to limit its scope. For example, variations of the present invention, while not shown and described herein, can also be considered within the scope of the present invention, such as variations in the materials from which the components of the present invention can be made; the size and perimeter configuration of many of the present invention components; as well as the relative positioning of some present invention components. Thus, the scope of the present invention should be determined by the appended claims and their legal equivalents, rather than being limited to the examples given. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  is a sectional view of the input end of the most preferred embodiment of the present invention showing its outer primary shaft, secondary primary shaft, torque converter, stator, turbine, oil pump, clutch pack, gear reduction band, and the clearance groove in the enlarged downstream end of the secondary primary shaft into which the planetary gear assembly is positioned. 
       FIG. 2  is a side view of the output end of the most preferred embodiment of the present invention showing its sun gear, a planetary gear assembly positioned upstream from the sun gear, the differential gears positioned in a carrier downstream from the sun gear, the inner primary shaft, the output shaft, a reverse band, and drum. 
       FIG. 3  is a sectional view of the most preferred embodiment of the present invention showing both input and output ends connected to one another, in addition to the governor and parking system, and with arrows showing the direction of oil movement. 
       FIG. 4  is a rearward view of the output end of the most preferred embodiment of the present invention showing its drum, reverse band, the clearance between drum and reverse band, and reverse servo. 
       FIG. 5  is an end view of the planetary gear assembly used in the most preferred embodiment of the present invention. 
       FIG. 6  is a side view of the inner primary shaft and the output shaft of the most preferred embodiment of the present invention showing the downstream end of the inner primary shaft and the upstream end of the output shaft being connected to opposing ones of the four beveled differential gears within a carrier centrally position the two shafts, the two opposed beveled gears also being positioned within the carrier and connected to a spider gear pinion shaft, with  FIG. 6  further showing a sun gear positioned upstream to the carrier, a drum positioned to engage a portion of the carrier, a reverse band positioned for being tightened around the drum, and a governor and parking system positioned downstream from the carrier. 
       FIG. 7  is a rear end view of the inner primary shaft in the most preferred embodiment of the present invention and servo, with a gear reduction band around the geared portion of the shaft, the secondary primary shaft, and clearance grooves for band tightening also being shown. 
       FIG. 8  is an end view of the parking system used as a part of the most preferred embodiment of the present invention, with broken lines depicting its pawl in a non-engaged position. 
       FIG. 9  is a torque flow diagram for the most preferred embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The following explains the progression and torque multiplication process of the present invention infinitely variable geared transmission. Its input shaft  1  from the engine (not shown) rotates the impeller end of the hydrodynamic torque converter  2 , which is positioned adjacent to a stator  3  and a turbine  4 . As the torque converter  2  rotates, the oil therein is spun outward radially, as illustrated by the arrow  22  in  FIG. 2 , whereby contact between the moving oil and turbine blades causes the turbine  4  to rotate. The rotating turbine  4  then causes rotation of the inner primary shaft  10 , the sun gear  11  attached near to the output end of the inner primary shaft, and the differential gear  13  attached at the downstream end of the inner primary shaft  10 . Movement of turbine  4  does not initiate rotation of output shaft  17 . However, at this point the outer primary shaft  5  is also turning at engine/input speed. Outer primary shaft  5  always runs at engine/input speed, being driven by the stator. Outer primary shaft  5  rotates the clutch assembly  7  and the oil pump  6 , which supplies oil pressure for lubrication and pressure to activate the clutch pack  8 . Oil pump  6  also supplies oil pressure for movement of a gear reduction band  15  associated with the planetary gear assembly  12  and a reverse band  20  associated with the beveled differential gears  13  positioned within the carrier  14  that is downstream from the sun gear  11  and planetary gear assembly  14 . Oil pump  6  further maintains the proper oil capacity in torque converter  2 . When the stator  3  that is adjacent to torque converter  2  is stalled by the discharge of oil in the torus trying to reverse its rotation, such reverse rotation is prevented by engagement of the gear reduction band  15  associated with the planetary gear assembly  12 . When tightened, gear reduction band  15  stops the rotation of secondary primary shaft  9 , causing the planetary gears  12  positioned within the clearance groove  27  in expanded downstream end of second primary shaft  9  to walk inside the internal gear at a speed slower than the sun gear  11 , which is attached to the inner primary shaft  10  and turning at engine/input speed. Since the tightening of gear reduction band  15  also slows the carrier  14  and the differential gears  13  it contains, gear reduction band  15  causes carrier  14  to rotate at the same speed as planetary gear assembly  12 , which is less than the speed of the inner primary shaft  10  and gives the present invention as a whole its first gear reduction. When the revolutions per minute are increased, the hydrodynamic conditions in torque converter  2  tend to approach the same speed around the torus inside converter  2 . This causes the outer primary shaft  5 , the inner primary shaft  10 , and the secondary primary shaft  9  to run at slightly different rotational speeds. At this point, the gear reduction band  15  is released and the clutch pack  8  is engaged, letting the secondary primary shaft  9  rotate at engine/input speed. Also at this point, the internal gear attached to the secondary primary shaft  9  will be attached mechanically to the stator  3  and the impeller of torque converter  2 . The turbine  4  is not yet up to engine/input speed, since the hydrostatic lock-up in the torus has not occurred, allowing the inner primary shaft  10  and turbine  4  to both turn at a speed less than that of engine/input speed. Inner primary shaft  10  will permit the differential gears  13  and their carrier  14  to turn about its axis, thereby reducing the amount of rotational speed transmitted to output shaft  17 . However, the created speed differential causes an increase in the torque that is applied to carrier  14 . When the torque converter  2 , stator  3 , and turbine  4  achieve a hydrostatic lock, the speed of the outer primary shaft  5 , secondary primary shaft  9 , and inner primary shaft  10  are then running at the same speed, giving the unit a 1:1 lock-up from the inner primary shaft  10  to output shaft  17 . This is where the clutch pack  8  is activated to secure a mechanical lock-up to back up the hydrostatic lock between the inner primary shaft  10  and output shaft  17 . At this point the engine speed and speed of output shaft  17  are the same. When a hydrostatic lock-up occurs inside torque converter  2 , the oil spinning inside its torus (the direction of which is indicated by arrow  22 ) comes to a stop and the oil is in a hydrostatic lock centrifugally. The preferred parking system  23  and governor  16  of the present invention are available as standard Ford products, except for the pawl  24  associated with parking system  23 , which is new. The reverse band  20  secures a drum  21  positioned around a portion of carrier  14  between the differential gears  13  and the parking system  23 . When the reverse band  20  is tightened to engage drum  21 , the drum  21  stops the rotation of the carrier  14 , the inner primary shaft  10 , and the output shaft  17 , and then causes output shaft  17  to rotate in a reverse direction to that of the inner primary shaft  10 . Further, the detail of the valve body required for use with the present invention is not shown, and will be designed conventionally according to the intended application. 
     FIGS. 1–3  show the most preferred embodiment of the present invention.  FIG. 1  shows the relative positioning of outer primary shaft  5 , secondary primary shaft  9 , torque converter  2 , stator  3 , and turbine  4 , with turbine  4  providing the rotational communication between the input shaft  1  from an associated engine (not shown) and the inner primary shaft  10  (which are both shown in  FIG. 3 ). In addition,  FIG. 1  shows oil pump  6  positioned downstream from outer primary shaft  5 , with clutch assembly  7  and clutch pack  8  positioned downstream from oil pump  6 .  FIG. 1  further shows the gear reduction band  15  positioned around the enlarged downstream end of secondary primary shaft  9  having the clearance groove  27  which houses the planetary gear assembly  12  when input and output ends of the present invention are connected. When gear reduction band  15  is tightened, it stops the rotation of secondary primary shaft  9 , causing the planetary gears  12  (shown in  FIGS. 2 and 3 ) to walk inside the internal gear at a speed slower than the sun gear  11  (also shown in  FIGS. 2 and 3 ), which is turning at engine/input speed. Since the tightening of gear reduction band  15  also slows the carrier  14  and the differential gears  13  it contains (as illustrated in  FIG. 3 ), gear reduction band  15  causes carrier  14  to rotate at the same speed as planetary gear assembly  12 , which is less than the speed of the inner primary shaft  10  and gives the present invention as a whole its first gear reduction. 
     FIG. 2  shows the output end of the most preferred embodiment of the present invention with planetary gear assembly  12  upstream from sun gear  11  that is attached to inner primary shaft  10 , while  FIG. 3  shows the input and output ends connected with the inner primary shaft  10  positioned within the secondary primary shaft  9 , thereby concentrically positioning the sun gear  11  within the planetary gear assembly  12 .  FIGS. 2 and 3  further show four beveled differential gears  13  positioned within a carrier  14  downstream from sun gear  11 , with reverse band  20  and drum  21  situated for tightening around the middle portion of carrier  14 .  FIGS. 2 and 3  show one beveled differential gear  13  attached to the downstream end of inner primary shaft  10 , and a second beveled differential gear  13  attached to the upstream end of output shaft  17 . In addition,  FIGS. 2 and 3  show two additional beveled gears  13  being attached to spider gear pinion shaft  26  in positions directly opposed to one another within carrier  14  so as to engage the two opposing beveled differential gears  13  attached to inner primary shaft  10  and output shaft  17 .  FIGS. 2 and 3  also show reverse band  20  and drum  21  positioned for tightening around carrier  14  to stop the rotation of carrier  14 , inner primary shaft  10 , and output shaft  17 , whereafter output shaft  17  is caused to rotate in a reverse direction to that of the inner primary shaft  10 .  FIG. 3  further shows the parking system  23  and governor  16  positioned concentric to output shaft  17  downstream from carrier  14 . The preferred pawl  24  used with the present invention parking system  23  is shown in  FIG. 8 . A torque flow diagram for the most preferred embodiment of the present invention is also provided as  FIG. 9 . 
     FIGS. 4 and 5  respectively show the output end of the most preferred embodiment of the present invention with its drum  21 , reverse band  20 , and reverse servo  19 , and the front end of the planetary gear assembly  12  also used in the most preferred embodiment of the present invention. Reverse servo  19  and the servo  18  shown in  FIG. 7  are hydraulic and of common design. When reverse band  20  is tightened around drum  21  to stop the rotation of carrier  14 , the rotation of inner primary shaft  10  and output shaft  17  is also stopped, whereafter output shaft  17  is caused to rotate in a reverse direction to that of inner primary shaft  10 .  FIG. 5  shows planetary gear assembly  12  having a three-geared structure. Although it is not critical, the three-geared structure for planetary gear assembly  12  is preferred. 
     FIG. 6  shows the inner primary shaft  10  and the output shaft  17  of the most preferred embodiment of the present invention with the downstream end of the inner primary shaft  10  and the upstream end of the output shaft  17  each being connected to one of the four beveled differential gears  13  within carrier  14 . The beveled gears  13  attached to inner primary shaft  10  and output shaft  17  engage two opposed beveled gears also positioned within carrier  14  that are connected to a spider gear pinion shaft  26 .  FIG. 6  also shows sun gear  11  attached to inner primary shaft  10  and positioned upstream from carrier  14 , as well as drum  21  positioned around the middle portion of carrier  14  and prepared to engage it to stop its rotation. Reverse band  20  is positioned for tightening around drum  21 , so that when reverse band  20  is activated it engages drum  21  to stop rotation of carrier  14 , as well as the rotation of inner primary shaft  10 , and output shaft  17 , whereafter the output shaft  17  is caused to rotate in a reverse direction to that of inner primary shaft  10 .  FIG. 6  further shows the downstream positioning of governor  16  and parking system  23  relative to carrier  14 , as well as a small portion of the present invention tail housing  25 . 
     FIG. 7  shows the inner primary shaft  10  in the most preferred embodiment of the present invention and servo  18 , with gear reduction band  15  around the geared portion of shaft  10  that would contain the planetary gear assembly  12 . Servo  18  is hydraulic and of common design. Positioned immediately interior to gear reduction band  15 ,  FIG. 7  also shows a band/shaft clearance groove  28 , with various portions of enlarged downstream end of secondary primary shaft  9  shown between inner primary shaft  10  and the planetary gear assembly  12 , including the clearance groove  27  that is also identified in  FIG. 1 . Gear reduction band  15  is positioned to stop the rotation of secondary primary shaft  9  and slow the rotation of the planetary gear assembly  12 , as well as slow the carrier  14  that houses differential gears  13 . When gear reduction band  15  is released, clutch pack  8  is engaged to bring the rotational speed of secondary primary shaft  9  to engine/input speed, until hydrostatic lock is achieved. 
     FIG. 8  shows the parking system  23  for the most preferred embodiment of the present invention and its associated pawl  24 . Solid lines for pawl  24  show its engaged position with parking system  23 , while broken lines show its non-engaged position relative to parking system  23 . The configurations of pawl  24  and parking system  23  shown in  FIG. 8  are preferred, but not critical. The preferred parking system  23  of the present invention is a standard parking system used on Ford products, except for the pawl  24 , which is new. The preferred location of parking system  23  is downstream from differential gears  13 , adjacent to governor  16 .