Abstract:
A gear drive assembly for internal combustion and heat engines requiring the conversion and transfer of reciprocal linear powered motion input into undirectional rotary output. A rack and pinion assembly having linear power input on the rack and a one-way friction clutch engageable by a pinion gear coupled with a concentric movement cam ring. Cam followers on the rack drive the linear motion input on its return non-power stroke imparting enhanced momentum input thereto.

Description:
This application claims the benefit of Provisional Application No. 60/427,057, filed Nov. 18, 2002. 

   BACKGROUND OF THE INVENTION 
   1. Technical Field 
   This invention relates to internal combustion engines and heat engines of the type that require the transfer of reciprocating movements of the piston into rotary output. Specifically, the invention is directed to enhance the efficiency of conversion to linear to rotation motion. 
   2. Description of Prior Art 
   Prior art devices have been directed to a variety of reciprocating piston engine designs and assemblies for transferring reciprocating output into effective usable rotary motion, see for example U.S. Pat. Nos. 1,567,172, 2,482,136, 4,791,894, 4,907,548, 5,233,949 and 5,394,839. 
   In U.S. Pat. No. 1,567,172 an internal combustion engine is disclosed having a pivoted lever output assembly enhancing the effective crank stroke. An alternate form of the invention is also shown having a piston rod and a guide with a tooth portion engaging a geared segment mounted on a pin for an effective gear transfer. 
   U.S. Pat. No. 2,482,136 claims an engine having a coordinating mechanism for synchronization and rotation of a power shaft in an engine configuration. 
   U.S. Pat. No. 4,791,894 is directed to a reciprocating piston engine having an elongated gear roller and gear pinion mechanism to improve power transfer efficiency. 
   U.S. Pat. No. 4,907,548 claims a two-stroke cycle engine with linear gear drive. Counterweights are employed on the output shaft for enhanced performance. 
   Finally, an internal combustion engine is illustrated in U.S. Pat. No. 5,394,839 having piston rods connected to an eccentric rotary member within a large housing. A balance weight extends from each housing for offset and to supply smooth torque transitions. 
   SUMMARY OF THE INVENTION 
   The invention is directed to a gear drive transfer assembly to convert non-rotating drive input from a linear reciprocating source to usable rotational output with reduced loss of transfer energy. Internal combustion engines and compressors and other piston driven heat engine configurations that heretofore produce rotary output via reciprocating pistons and crank rods which never apply full torque transfer due to the connecting rod angle which have induced return stroke loss due to their power generating nature. The invention utilizes contoured cam surface on the drive shaft and cam followers that apply force to a piston rod rack during the non-powered return stroke and disengage during the power stroke utilizing the inherent kinetic energy within the components. This allows for maximum transfer of linear motion to torque by maintaining the optimum torque transfer relationship of pinion gear orientation to piston rack. 

   
     DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side elevational view of a graphic representation of the linear gear transfer drive assembly within a power stroke requirement for an internal combustion engine; 
       FIG. 2  is a side elevational view set forth in  FIG. 1  illustrating the progressive cam relation position; 
       FIG. 3  is a side elevational view set forth in  FIG. 1  illustrating the progressive cam relation position; 
       FIG. 4  is a side elevational view set forth in  FIG. 1  illustrating the progressive cam relation position; 
       FIG. 5  is a side elevational view set forth in  FIG. 2  at the end of the power stroke; 
       FIG. 6  is the side elevational view set forth in  FIG. 2  within the return piston stroke sequence; 
       FIG. 7  is the side elevational view set forth in  FIG. 2  within the return piston stroke sequence; 
       FIG. 8  is the side elevational view set forth in  FIG. 2  within the return piston stroke sequence; 
       FIG. 9  is the side elevational view set forth in  FIG. 2  within the return piston stroke sequence; 
       FIG. 10  is the side elevational view set forth in  FIG. 2  within the return piston stroke sequence; 
       FIG. 11  is a side elevational view of a graphic representation of the linear gear transfer drive assembly of the invention in use; 
       FIG. 12  is a top plan view on lines  12 — 12  of  FIG. 11 ; 
       FIG. 13  is an enlarged partial side elevational view of a one-way bearing and clutch assembly used with the invention; 
       FIG. 14  is a side elevational view of the cam configuration of the invention illustrating its rotational positioning in broken lines; and 
       FIG. 15  is a side elevational view of a modified graphic representation of the linear gear transfer assembly within a power stroke sequence for an internal combustion engine. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIG. 1  of the drawings, a primary gear transfer drive assembly  10  of the invention can be seen having a linear drive input rack  11  with oppositely disposed spaced upstanding arms  12  and  13  extending there from. A gear surface  14  extends along the surface between said respective arms. Each of the arms  12  and  13  have cam roller follower assemblies  12 A and  13 A respectively thereon for selective engagement with a camming element  15 . 
   The camming element  15  has a contoured outer engagement surface  16  with an integral apertured mounting lug  17  within an area defined by the camming engagement surface  16 . A pinion gear  18  is positioned on a torque transfer drive assembly  19 , illustrated generally in  FIG. 5  of the drawings. A corresponding output drive shaft  20  extends through the bearing assembly  19  being selectively engaged thereby for rotary drive output as indicated by the directional arrow  21 . The cam  15  is selectively engaged by the drive shaft for imparting return force to the drive input rack  11  as will be discussed in greater detail hereinafter. 
   Referring to  FIGS. 1–4  of the drawings, a sequential path of the camming element  15  and a piston P can be seen illustrating a power stroke PS in which cam follower  13 A is not in contact i.e. gap G with the cam surface  16  to reduce potential loss. In  FIG. 5  both cam followers  12 A and  13 A are engaged by the cam surface  16  at the bottom of the power stroke BPS. The linear force input of the rack  11  drives the pinion gear  18  in a clockwise motion locking the one-way bearing and clutch assembly  19  and correspondingly rotating the drive shaft  20  for power drive output transfer. The non-power return of the rack  11  is illustrated in  FIGS. 6–10  sequentially in which the torque transfer assembly under counter-clockwise rotation arrow  21 A imparted thereto disengages from the pinion gear  18  allowing free rotation of same. 
   As the cam  15  continues to rotate clockwise with the drive shaft  20  under the initial power input via the torque transfer assembly  19  from the pinion gear  18 , the cam followers  12 A and  13 A on the ends of the respective upstanding arms  12  and  13  are driven thereby imparting input force to the rack&#39;s  11  non-powered return path. This action utilizes the kinetic energy within the cam element&#39;s  15  mass and therefore provides increased input to the return stroke overcoming the inherent torque loss between the piston and cylinder walls CW in a reciprocation directional pinion gear transfer power assembly heretofore. 
   The primary application of the gear transfer device assembly  10  of the invention is for an internal combustion engine having opposing gear transfer drive assemblies  10 A and  10 B as illustrated generally in  FIGS. 11 and 12  of the drawings in which a pair of piston rod racks  22  and  23  are interconnected to respective pinion gears  24  and  25  and interconnected cam assemblies  26  and  27 . The pinion gears  24  and  25  have respective torque transfer assemblies  28 A and  28 B selectively engaging an output drive shaft  29  operating as hereinbefore described. Cam follower pairs  30  and  31  are selectively engaged on the respective cam elements  26  and  27  in the same manner as noted above. The respective piston rod racks  22  and  23  are simultaneously driven with the efficient torque transfer of reciprocating linear motion into directional rotation of the drive shaft  29 . Roller bearings  30 A are used to maintain piston rod racks  22  and  23  in contact alignment within the assembly. 
   It will be noted that the respective cam followers  12 A and  13 B and cam follower pairs  30  and  31  all selectively engage the respective cam elements  15 ,  26  and  27  fully during the return, non-power stroke, and correspondingly disengage marginally during the power stroke as illustrated in sequence in  FIGS. 1–5 . It is this disengagement which is critical to the system operation without same the cam configuration surface  16  which has been selected for optimum energy return input would not be viable. 
   The torque transfer assemblies  19 ,  28 A and  28 B are well known within the art and in this example utilize a plurality of cam clutches  33  and standard ball bearings  34 . Such torque transfer assemblies are manufactured for example by Morris under Series KK35 as illustrated generally in  FIG. 5  of the drawings as will be well understood by those skilled in the art. Such cam clutches  33  allow an outer race  35  over running, non-driven transfer to an inner race  36  on the respective output drive shafts  20  and  29  as best seen in  FIG. 4  of the drawings. 
   The cam elements  15 ,  26  and  27  directionally rotate through a full 360 degree pattern as illustrated in  FIG. 14  of the drawings in which the primary position and engagement of the cam element  15  is shown in solid lines and the incremental 90 degree positioning of the cam is illustrated in broken lines along with the cam followers  12 A and  13 A which, as noted, impart a return force every other stroke which is evident from the above description. 
   As noted above, during the power stroke of the respective geared racks  11 ,  22  and  23 , the interengaged cam followers  12 A,  13 A and cam follower pairs  30  and  31  will momentarily disengage due to their fixed linear spacing to one another and the variable contoured engagement surface of the cam elements as hereinbefore described and best illustrated in  FIGS. 1–4  of the drawings. 
   It will be evident from the above descriptions that it is the cam element  15  configuration and its positioning on the drive shaft  29  that affords the utilization of available return stroke energy imparted during the reciprocating action of the power input thereon that provides the torque transfer and increase enhanced efficiency associated therewith as discussed will be applicable to any piston derived system in which reciprocating linear motors is to be converted to rotary output. 
   Referring to  FIG. 15  of the drawings, an alternate form of the invention can be seen in which a transfer roller  37  is rotatably positioned on the torque transfer drive assembly  19 . Correspondingly, a linear drive input rack  38  is shown having a roller engagement surface  39  which is frictionally engaged by the roller  38  under substantial torque transfer force affecting a linear to rotational motion transfer. 
   As set forth in the primary form of the invention, the roller  37  is mounted on a torque transfer drive assembly  40 . A plurality of pressure rollers  41  are positioned for force engagement on the linear drive input rack  38  opposite that of said transfer roller  37 . Secondary guide rollers  42  are engaged in oppositely disposed sides of the input rack  38  to stabilize and maintain required linear transfer travel path. Additionally, a resilient bumper  43  may be positioned within the assembly so as to be engageable by free end surface  44  of the input rack  38  to cushion the rack  38  at the end of its power stroke. 
   In some applications, it may be necessary to provide dual gear transfer drive assemblies attached to a single piston input source which would require to duplicate the transfer drive assembly  10  attached to the piston P of the appropriate configuration of engine, compressor or the like that derives its power from reciprocating linear sources. 
   It will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention.