CROSS-REFERENCE TO RELATED APPLICATION

[0001] The present application claims the benefit of U.S. Provisional Application

Serial No. 62/088,892 filed on December 8, 2014, the contents of which are incorporated herein fully by reference.

FIELD

[0002] The present invention is related to the field of motors and more specifically, a hydraulically driven spring drive motor.

SUMMARY

[0003] According to the present invention, a hydraulic spring drive apparatus is provided whereby independent spring force for rotation is continuously delivered by a number of expansible, compressible connecting means operating so that, at any given time, more connecting means are expanding than are being compressed.

[0004] As embodied in a presently preferred apparatus, a rotatable cam shaft has axially spaced along its length a number of cams fixed to the shaft for rotation therewith. Each cam has an edge varying in distance from a center of rotation of the cam between a maximum distance and minimum distance. A number of rocker arms, one following each cam, are pivotally attached, in a predetermined position, to the apparatus at one end and support at an opposite end expansible, compressible connecting means. A crank shaft having an eccentric crank portion for connection with each connecting means is rotatably driven by rotation of the cam shaft and reciprocal movement of the connecting means. In one embodiment, each cam is shaped so that the maximum distance at its edge extends through a minor portion (about 90°) of its 360° rotation and the minimum distance extends through a larger portion (about 135°) of rotation with a sharp rise from minimum to maximum distance and a gradual decline from maximum to minimum distance as the cam rotates. The arrangement at the edge of the cams provides compression of one connecting means opposed to expansion of a plurality of other connecting means. A hydraulic pump may be connected to the cam shaft for rotation with the cam shaft to aid in the operation of a throttle system. The throttle system may be used to control the rest position of the rocker arms by displacing a pressure bar connected to a rocker arm riding on each cam. Adjustment of the rocker arm controls the degree of compression and expansion of each connecting means.

DESCRIPTION OF THE DRAWING

[0005] Fig. 1 is a side sectional view of an apparatus of the present invention with portions removed for clarity.

[0006] Fig. 2 is an end view of the apparatus of Fig. 1, with portions removed for clarity.

[0007] Fig. 3 is a section view of the power unit assembly shown in Fig. 2.

[0008] Fig. 4 is a side view of an alternative cam used with the motor of Fig. 1.

[0009] Fig. 5 is a side view of the motor of the present invention showing a timing system thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0010] Referring now to Figs. 1 and 2, the present apparatus is contained in a rectangular housing 4 which supports a crank shaft 6, a cam shaft 8, and a rocker arm assembly 10. A hydraulic pump 12 and throttle assembly 14 are mounted on the housing.

[0011] The crank shaft 6 is mounted axially through an upper portion of the housing 4 through forward bearing 16 and rearward bearing 18 and comprises equally axially spaced eccentric crank portions 20 for each cam and connecting means, there being eight in the presently preferred embodiment. Each crank portion 20 comprises a pair of axially offset members and a cross piece 22 which rotates in a circle of a given diameter Dcr about the axis of rotation 24 of the crank shaft.

[0012] The cam shaft 8 is supported on a forward bearing 26 and a rearward bearing

28 and supports eight cams 30 in equally axially spaced relationship along its length, one opposite each crank portion 20. The cam shaft terminates forwardly in a pulley wheel 32 and rearwardly in a flywheel 34. The cam shaft may be journaled or splined to support engagement with the plurality of cams for rotation therewith.

[0013] The cams 30 are mounted in circumferentially offset relationship to each other so that each succeeding cam is offset from its rearwardly adjacent cam by 360° divided by the number of cams, or 45°. Similarly, each crank portion 20 is offset from its rearwardly adjacent crank portion by 45° so that , as shown in Fig. 2, a cam denominated 180 will be oppositely connected to a crank portion having its 180 portion engaging a rocker arm. A cam advanced 45° in the direction of arrow 36 is oppositely connected to a crank portion 225, and so forth. A timing gear 38 engages gears 40, 42 on the crank shaft and cam shaft, respectively, to maintain the cams and crank portion in the above-described predetermined relationship.

[0014] Each cam 30 is of the same modified disk shape having modified edge surface

41 as shown in Fig. 2. Each cam may be divided into eight sectors, 0-360. The edge surface of sectors comprising angles 135-225 are at a minimum distance from the axis 44 of rotation of the cams. Sectors 270 and 225 comprises a rate of 90° and the edge 41 of cam 30, is curved slightly outwardly. From 270° the edge continues at a maximum distance from axis to sector 0, along which it describes a circle of a diameter approximately Dcr. From sector 0, the cam gradually returns to a minimum distance in the vicinity of sector 90.

[0015] With reference to Figure 2, the rocker arm assembly 10 comprises an axially elongated pressure bar 46 supported through three axially spaced, upwardly extending rod portions 48-52 (Fig. 2). The rod portions 48, 50, 52 are slidably fitted into tube portions 49, 51 , 53 in the housing 4. Eight rocker arms 54 are pivotally connected to the pressure bar 46 to extend generally horizontally laterally to move in parallel pivotal directions as shown by arrow 56. Each rocker arm 54 moves in cooperation with a cam 30 and is connected to a power rod assembly 58. Each rocker arm 54 is of the same shape and may comprise a lower surface having a curved projection 60 which rides on the cam 30 and follows the cam through the edge variations described above. Alternatively, the projection 60 may comprise a roller bearing attached to the rocker arm. The outward portion 61 of the rocker arm is curved slightly downwardly so that the power rod assembly 58 joins the rocker arm at a portion thereof which is downwardly offset from the projection 60. A cavity portion 62 extends through the outward portion 61 of the rocker arm 54 to slidably receive a shaft 64 of the power rod assembly 58. A pin 66 pivotally supports and drivably engages a spring cup pivot 68 of the power rod assembly. [0016] The power rod assembly 58 transmits reciprocal movement of its associated rocker arm 54 to a corresponding crank portion 22 (Fig. 1) of the crank shaft 20 and supplements this motion through expansion of a spring member 72.

[0017] Turning to Figure 3, each power unit assembly 58 comprises an upper nose piece 70, a coil spring 72, the shaft 64, and a spring cup pivot 68. The upper nose piece 70 is rotatably fixed to its associated cross piece 22 on the crank shaft 20 and terminates downwardly in rim portion comprising a spring receiving aperture 69 and tow connecting rod apertures 71 to receive connecting rods 73. The coil spring 72 surrounds the shaft 64 and downwardly engages the spring cup 68. The shaft 64 is fixed to the nose piece 70 and extends to the spring cup 68 supported on the rocker arm 54. The spring cup 68 is pivotally supported on an upper surface of the rocker arm 54 and comprises an aperture to receive a lower coil of the coil spring 72. The power unit assembly 58 thus provides compressible, expansible connecting means translating the reciprocal pivotal movement of the rocker arm 54 brought about by the cam 30 into rotation of the crank shaft 20 accompanied by compression and expansion of the coil 72. Compression and expansion of the coil spring 72 takes place as the spring cup 68 rides on the rocker arm 54 and slides along the shaft 64 towards the nose piece 70.

[0018] The relationship between the various crank portions, cams, and springs is

The above crank shaft positions are those which each individual crank portion goes through during a complete revolution and also those of each member at a given moment.

[0019] Returning to Figure 1, the hydraulic a pump 12 is used to assist the throttle assembly 14. The throttle assembly 14 comprises two hydraulic fluid reservoirs, a power assist reservoir 80 and a master reservoir 82. The master reservoir 82 is the main reservoir and controls the amount of hydraulic pressure from pump 78 delivered through lines 84 to the tube portions 49, 51 and 53 of the rocker arm assembly 58. A source of electric energy 74 controlled by a switch 76 drives an electric pump 78 which develops pressure in the master reservoir 82. Pressure in the tube portions 49, 51 and 53 forces the rocker arm rods 48, 50 and 52 downward, pivoting the rest position of the rocker arms toward the crank shaft 20. Springs 86 in each tube 49, 51 and 53 help to force the rods 48, 50 and 52 downward to a rest position. Pressure in the tubes 49, 51 and 53 is increased through a sliding piston 87 in the master reservoir 82. The force from the pump 78 initiates and facilitates movement of the piston 87 to decrease reservoir area and increase pressure in the tubes 49, 51 and 53. The piston 87 is reciprocally movable through a shaft 88 connected to a second piston 90 in the power assist reservoir 80. The second piston 90 also moves forward to displace the first piston 87 to increase pressure in the tubes 49, 51 and 53. Pressure from the hydraulic pump 12 is delivered through lines 92, 94 to a first chamber portion 96 of the power assist reservoir 80 and a second chamber portion 98, containing the piston 90, of the power assist reservoir. Flow through the first chamber portion is controlled by a sliding plate 102. The sliding plate 102 is connected to a piston 104 in the first chamber portion 96 and controlled by a rod 106. Movement of rod 106 increases pressurized fluid flow to the second chamber portion 98 to move the piston 90 forward. The pump 12 is driven by a belt 108 from the cam shaft 8 so that increased motor rpm provides increased pressure for moving the pressure bar. The amount of this pressure delivered to the piston 90 is controlled by the plate 102. For maximum power output from the present apparatus, increased pressure is delivered to the pressure bas as cam shaft rpm increases. This pressure may be throttled back by movement of the plate 104 to cut off pressure to the piston 90. [0020] The present apparatus may further comprise an oiling system. An oil hose 112 is connected to each one of the connecting shafts 64. Each shaft 64 has an oil channel running through the center of the shaft full length to two holes 114, 116, at the top of the nose piece 70. The hose 112 which is attached to the end of the connecting shaft 64 is also connected to a main oil line that is connected to an oil pump 118 driven by the cam shaft 8 through the use of a gear.

[0021] When oil is pumped up through the connecting shaft it oils bearings on each one of the crank shaft throws. It also oils and keeps the coil springs from getting hot and losing their tension. This is done by forcing the oil out through the two oil holes 114, 116 at the top of the nose piece 70 into a reservoir. This reservoir is created by the uses of a rubber shelf in the nose piece 70 that is clipped to the nose piece of the connecting rod and also clipped to a conventional spring cup and by forming a reservoir.

[0022] The rubber shelf has holes in it about 2/3 of the way up from the bottom of the shelf, allowing the oil to be forced out when the coil spring is being compressed and by doing this it stops the rubber shelf from ballooning. On the power stroke the cooled oil is forced back into the reservoir because the coil spring is being expanded allowing the oil to fill up the reservoir and cooling off the coil spring. The main bearings are oiled similarly. There are oil ports drilled in each one of the supports and an oil hose is connected to each one.

[0023] Turning to Figure 4, an alternative, and preferable, cam configuration is shown. The cam 212 has a profile that varies in distance from the rotational axis 44 (Fig. 4) about 360 degrees. As discussed before eight (8) cams 212 are connected to the splined cam shaft 8 and spaced apart to engage the projections 60 formed on the lower portion of the rocker arms. Alternatively, the projections 60 (Fig. 2) may be replaced with roller bearings mounted to the rocker arms and disposed to roll along the cam edge 41 as the arms rise and fall. The cams 212 are mounted on the splined cam shaft 8 in a circumferentially offset relationship. In a preferred configuration cam 7 is offset 45 degrees from cam 1 , cam 4 is offset 45 degrees from cam 7, cam 6 is offset 45 degrees from cam 4, cam 2 is offset 45 degrees from cam 6, cam 8 is offset 45 degrees from cam 2, cam 3 is offset 45 degrees from cam 8, cam 5 is offset 45 degrees from cam 3, and cam 1 is offset 45 degrees from cam 5. The importance of this offset assembly will be discussed hereinafter.

[0024] The cam 212 differs from cam 30 in the profile of its outer edge 41. Cam 212, like cam 30, may be divided into eight (8) sectors defined by 45 degrees of angular rotation. However, cam 212 has a generally kidney bean shape, the importance of which will become evident with further description. The cam profile is configured so that the spring 72 is idling during the rocker arms' travel from 315 degrees to 135 degrees. When the projection reaches 135 degrees, as the cam rotates counter-clockwise, the profile rises from 135 degrees to 225 degrees and comprises the compression stage edge 214. This rise comprises the compression phase of the cam's rotation. At 225 degrees the spring associated with the rocker arm is fully compressed and begins to lift the rocker arm and cause rotation of the crank shaft. The stored energy from spring 72 causes the rotation of the cam shaft and crank shaft via timing system (Figure 5). As the cam 212 rotates to 270 degrees the spring has expended 50% of the compression energy. When the cam reaches 315 degrees the spring as released the compression energy acquired during the compression phase and entered an idle phase. The portion of the edge from 225 degrees to 315 degrees is the power stage edge 216. The edge from 315 degrees to 135 degrees is the idle stage edge 218. The spring remains in the idle phase as the cam rotates from 315 degrees back to 135 degrees.

[0025]

The values in the table above cycle as the 100% and 50% compressed springs expand and cause the cam shaft to rotate to move the idle springs from an idle state to a compressed state.

[0026] Referring to the above table, the spring associated with cam 6 is 0% compressed. However, as cam 6 is rotated the counterclockwise the distance between the cam shaft and the edge of the cam rises four (4) inches from 135 degrees to 225 degrees. This causes compression of the spring. As the cam continues to rotate from 225 to 315 degrees the spring decompresses and expands transferring the linear energy of the spring to cause rotation of the crank shaft. The distance between the cam shaft and the edge of the cam from 225 degrees to 315 degrees rises another 4.5 inches from the 225 degree location. At 315 degrees the spring has released its energy and enters an idle phase until the cam rotates around back to 135 degrees. At this point the cam profile begins to rise and compression of the spring is repeated.

[0027] Thus, while two springs are compressing at least two others are expanding to transfer rotational energy to the crank shaft and the remaining 4 are idling around from 315 degrees to 135 degrees to the next compression.

[0028] With reference to Figure 5, the timing system of the present invention is shown. The motor is shown from a side on the outside of housing 4. The timing system comprises a timing chain 200 that is routed around a cam shaft wheel 202 connected to the cam shaft 8 for rotation therewith, a crank shaft wheel 204 connected to the crank shaft 6, and a plurality of toothed gears 206 and 207. Gear 207 is disposed on an output shaft 211 adapted to transfer the rotational output power of the motor to the implement driven by the motor. A tension adjustment assembly comprising a tension wheel 208 movable within a slot 210 formed within the housing 4 is used to adjust the tension on the chain 200. The timing system comprises five gears and/or pulleys that rotationally connect the cam shaft and the crankshaft to cause the cams 212 and cam shaft 8 to rotate, for example, counter clockwise while the crank shaft rotates clockwise and maintains the timing of rotation of the cam shaft relative to the crank shaft.

[0029] Various modifications can be made in the design and operation of the present invention without departing from the spirit thereof. Thus, while the principal preferred construction and modes of operation of the invention have been explained in what is now considered to represent its best embodiments, which have been illustrated and described, it should be understood that the invention may be practiced otherwise than as specifically illustrated and described.