PORTABLE WOOD LOG SPLITTER

Abstract

Disclosed herein is a portable wood log splitter comprising a power unit and a work tool. The power unit comprises an engine and a gear box while the work tool comprises a drive shaft having a spreading mechanism and a splitting threaded cone. In some embodiments, the work tool is releasable from an output shaft of the gear box. The drive shaft of the work tool is hollow and provided with a thread on the outer circumference to drive the spreading mechanism. A nut with a toothed disc resides on the thread and able to shift in the axial direction of the drive shaft rotation axis due to rotation of the drive shaft. In operation, the splitting threaded cone is driven by force of the power unit to initially fracture a log, then using the spreading mechanism, the portions of the split log are fully separated under power.

Claims

1-17. (canceled)

18. A portable wood log splitter comprising: a power unit; said power unit comprising an engine; said power unit comprising a gear box; said gearbox comprising a gearbox output shaft; a work tool; said work tool comprising a drive shaft; a spreading mechanism; said spreading mechanism mounted on said drive shaft on one end; a splitting threaded cone; said drive shaft comprising said splitting threaded cone coupled at the other end; said splitting threaded cone having a threaded profile on an outer circumference; said work tool releasably coupled to said output shaft at an opposing end; said spreading mechanism comprising a nut; said spreading mechanism comprising a toothed disc; said nut having said toothed disc on one end of said nut; said drive shaft extending through said nut; said nut with said toothed disc translatable axially when said drive shaft rotated; a freely rotating circular disc; said freely rotating circular disc positioned between said gear box output shaft and said toothed disc; an end stud; said end stud coupled to said drive shaft; said end stud releasably connected to said splitting threaded cone; a telescopic spiral spring; said telescopic spiral spring encircling said drive shaft; and said telescopic spiral spring biasing said nut and toothed disc towards said gearbox.

19. The portable wood log splitter of claim 18 further comprising: said gear box output shaft having a central axis; a ball coupling; a sleeve; said gear box output shaft encircled by said sleeve; said drive shaft having a groove operable to seat a ball; a ball coupling; said ball coupling comprising at least one ball; a compression spring encircling said gear box output shaft; said ball coupling operable by manually by shifting said sleeve in an axial direction; whereby said sleeve blocks said ball against movement perpendicular to said central axis in a locked position thereby providing for the transfer of torque between said gearbox output shaft and said drive shaft.

20. The portable wood log splitter of claim 18 further comprising: an end stud; said end stud extending from said drive shaft; whereas a bayonet coupling is utilized for the repeated coupling and uncoupling of said splitting threaded cone to said end stud.

21. The portable wood log splitter of claim 18 whereas said power unit comprises said engine with an integral gear box.

22. The portable wood log splitter of claim 18 further comprising: a building kit operable to form said power unit; said power unit comprising a chain saw power unit; said chain saw power unit comprising a chain saw cutting blade flange on said chain saw power unit; said building kit comprising said chain saw power unit and said gear box; whereas said gear box is removably fixed to said chain saw cutting blade flange.

23. The portable wood log splitter according to claim 21 further comprising: said engine having an engine output shaft; said engine output shaft having a central axis; said gear box output shaft comprising a central axis; said gear box output shaft central axis situated perpendicular to said engine output shaft central axis; a belt drive; said gear box comprising two gears coupled by said belt drive; a pinion gear shaft driven by said one of said two gears; a crown gear; said pinion gear shaft drives said crown gear; and said gear box output shaft is consequently driven by said crown gear.

24. The portable wood log splitter of claim 23 further comprising: a bevel gear; said bevel gear self-locking in said gear box; said bevel gear comprising a pinion gear shaft; said bevel gear comprising a crown gear; wherein said pinion gear shaft is adjacent said crown gear; bearings; said bearings positioned on each end of said pinion gear shaft.

25. The portable wood log splitter of claim 21 further comprising: said engine having an engine output shaft; said engine output shaft having an engine output shaft central axis; said gear box comprising a gear box output central axis; said engine output shaft central axis being parallel to said gear box output central axis; said gear box is multi-gear; whereas said gear box is formed by gear wheels or planet one.

26. The portable wood log splitter of claim 21 further comprising: said gearbox output shaft having a central axis; an anti-torque bar operable to eliminate reaction torque generated during operation; said anti-torque bar fixed to one of said power unit and said gear box; whereas said anti-torque bar longitudinal axis is angled between 60 and 120 degrees from said gear box output shaft central axis.

27. The portable wood log splitter of claim 21 further comprising: a second handle; said second handle coupled to said power unit; a revolution controller; said second handle having a central axis; and whereas said central axis of said second handle is parallel to said work tool central axis in an operable mode.

28. The portable wood log splitter of claim 18 further comprising: a nut; said drive shaft comprising a drive shaft thread on an outer circumference of said drive shaft; and whereas said drive shaft and nut are configured as A or B whereas: A) said drive shaft thread being trapezoidal, and said nut directly interfaces said drive shaft through said trapezoidal thread, or B) whereby said portable wood log splitter further comprises balls; and whereas said drive shaft thread and said nut operate with said balls therebetween for operation as a ball screw.

29. The portable wood log splitter of claim 18 further comprising: an end stud; said end stud having a central axis; said end stud coupled to said drive shaft at a distal end; said end stud having a pair of opposed rectangular projections spaced 180 degrees from each other; said opposed rectangular projections having a shape offset; said opposed rectangular projections situated perpendicular to said end stud central axis; a cone inlet opening in said splitting threaded cone; said cone inlet expanding into a threaded cone recess; said inlet opening profile configured to pass said pair of opposed rectangular projections through said cone inlet opening in a first position; and whereas said rectangular projections are secured within said threaded cone recess when rotated to a second position.

30. The portable wood log splitter of claim 18 further comprising: an inlet opening in said splitting threaded cone at one end; an end stud; said end stud at a distal end of said drive shaft; a recess extending from said inlet opening configured to receive said end stud therein; and a spring housed within said splitting threaded cone.

31. The portable wood log splitter of claim 3 further comprising: said splitting threaded cone comprising an inlet opening; a recess adjacent said inlet opening; said bayonet coupling comprising said end stud seated in said recess; and said end stud rotated in said recess between 10 and 90 degrees thereby securing said splitting cone against axial movement.

32. The portable wood log splitter of claim 18 whereas the surface roughness of said thread profile of said splitting threaded cone is less than Ra 0.4 um.

33. The portable wood log splitter of claim 18 further comprising: a tube; said tube containing lubricating oil; said tube supplying said lubricating oil to said cone thread profile; one or more hydraulic valves; said drive shaft being hollow; said lubricating oil flowing through said hollow of said drive shaft; said splitting threaded cone having a cone inlet opening; said one or more hydraulic valves operable to control flow of said lubricating oil; and whereas said lubricating oil is conveyed on said cone thread profile of said splitting threaded cone by action of gravitational force.

34. The portable wood log splitter of claim 18 further comprising: a tube; said tube supplying lubricating oil to said cone thread profile; a spring; whereas said lubricating oil is dispensed consequent an up to 10 mm shift of said splitting threaded cone on said end stud towards said power unit by an applied axial force; and whereas compressed said spring shifts said splitting threaded cone on said end stud away from said power unit when said axial force is removed.

35. A portable wood log splitter comprising: a power unit; a gear box; said gear box coupled to said power unit; a work tool; said work tool comprising a drive shaft; said drive shaft coupled to said gear box; said drive shaft comprising a drive shaft thread on an outer circumference of said drive shaft; a splitting threaded cone; said splitting threaded cone coupled to one end of said drive shaft and operable to fracture a log when driven into the log under power transmitted from said power unit; a spreading mechanism; said spreading mechanism comprising a nut and a toothed disc; said nut fixed to said toothed disc; a freely rotating circular disc; and whereas said nut with said toothed disc translates down said drive shaft thread causing consequent separation between said freely rotating circular disc and said toothed disc and thereby operable to separate fractured logs when said toothed disc and said freely rotating circular disc are placed in the crack of a log.

36. The portable wood log splitter of claim 35 wherein said work tool is releasable from said power unit and whereas said work tool and said power unit are provided as a kit.

37. A method of splitting wood comprising the steps of: obtaining a log; obtaining a portable wood log splitter comprising a power unit imparting torque to a drive shaft having a splitting threaded cone coupled at one end and a spreading mechanism having two discs positioned over said drive shaft; driving said splitting threaded cone into the log causing it to split in a first stage; inserting a portion of the two discs of the spreading mechanism into the split of said log; and activating said spreading mechanism whereby the two discs are forcefully separated under power to drive the split log apart in a second stage.

38. The portable wood log splitter according to claim 22 further comprising: said engine having an engine output shaft; said engine output shaft having a central axis; said gear box output shaft comprising a central axis; said gear box output shaft central axis situated perpendicular to said engine output shaft central axis; a belt drive; said gear box comprising two gears coupled by said belt drive; a pinion gear shaft driven by said one of said two gears; a crown gear; said pinion gear shaft drives said crown gear; and said gear box output shaft is consequently driven by said crown gear.

39. The portable wood log splitter of claim 22 further comprising: said gearbox output shaft having a central axis; an anti-torque bar operable to eliminate reaction torque generated during operation; said anti-torque bar fixed to one of said power unit and said gear box; whereas said anti-torque bar longitudinal axis is angled between 60 and 120 degrees from said gear box output shaft central axis.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0029] These and other features and advantages of the present invention will become more readily appreciated when considered in connection with the following detailed description and appended drawings, wherein each drawing is according to one or more embodiments shown and described herein, and wherein:

[0030] FIG. 1 depicts an overall arrangement of the device according to the invention in an axonometric view—a variant wherein the power unit of the device comprises an engine and a gear box, which is its integral part (illustrated here in an operable configuration at the top and partially exploded at the bottom);

[0031] FIG. 2—is an overall arrangement of the device according to the invention in an axonometric view—a variant wherein the power unit of the device comprises a building kit of a chain saw power unit and a separate auxiliary gear box which will be attached dismantably onto the chain saw cutting blade flange (illustrated here in an operable configuration at the top and partially exploded at the bottom);

[0032] FIG. 3—is a detail of the spreading mechanism in an axonometric view (illustrated here in an operable configuration at the top and partially exploded at the bottom);

[0033] FIG. 4—is a detail of operation of the ball coupling of the gear box output shaft and the drive shaft of the work tool in section (illustrated at top with drive shaft coupled and at bottom with drive shaft uncoupled);

[0034] FIG. 5—is a detail view of an arrangement of the gear box with the bevel gear (the illustration at the top and the illustration at the bottom are from opposed viewing angles);

[0035] FIG. 6—is an exploded detail of an arrangement of the bayonet coupling of the end stud and the splitting cone;

[0036] FIG. 7—is an end view illustration of bayonet coupling operation;

[0037] FIG. 8—is a partially exploded sectional view of the device showing lubricating oil supply tube;

[0038] FIG. 9—are sectional illustrations of opening and closing of the lubrication oil flow inside the threaded cone.

DETAILED DESCRIPTION OF SELECTED EMBODIMENTS OF THE INVENTION

[0039] Select embodiments of the invention will now be described with reference to the Figures. Like numerals indicate like or corresponding elements throughout the several views and wherein various embodiments are separated by letters (i.e. 100, 100B, 100C). The terminology used in the description presented herein is not intended to be interpreted in any limited or restrictive way, simply because it is being utilized in conjunction with detailed description of certain specific embodiments of the invention. Furthermore, embodiments of the invention may include several novel features, no single one of which is solely responsible for its desirable attributes or which is essential to practicing the invention described herein.

Example 1

[0040] The portable wood log splitter in the exemplary embodiment of the invention comprises a building kit of a power unit and of a work tool. The power unit I consists of an engine Ia and a gear box Ib, which is its integral part (see FIG. 1). The work tool II consists of a drive shaft 1 complete with a spreading mechanism 2 and of a splitting threaded cone 3 (see FIG. 1). The work tool II and an output shaft 4 of the gear box Ib are provided with parts of an element for a repeatable connection and disconnection of the splitting threaded cone. The drive shaft 1 of the work tool II is hollow and to produce the spreading mechanism 2 (see the detail in FIG. 3) is on the outer circumference provided with a drive shaft thread 1b, on which a nut 5 connected with a toothed disc 6 is screwed, the said nut being able to shift in the axial direction of the drive shaft 1 rotation axis due to rotation of the drive shaft 1 on the drive shaft 1 between its connection to the output shaft 4 of the gear box Ib and the said nut 5 with the toothed disc 6, a freely rotating circular disc 7 having a smooth outer surface and being secured against a shift in the axial direction of drive shaft 1 rotation axis is inserted, the shaft 1 being its integral part.

[0041] In the terminal part of the drive shaft 1 an end stud 8 is screwed, the said end stud 8 having an element for a repeatable connection and disconnection of the splitting threaded cone 3. Between the nut 5 with the toothed disc 6 and the end stud 8 of the drive shaft 1, a telescopic spiral spring 12 is inserted, which shifts the nut 5 with the toothed disc 6 back to its starting position and simultaneously serves as a casing of the thread 1b on the drive shaft 1 during its expansion.

[0042] The element for the repeatable connection and disconnection of the drive shaft 1 of the work tool II and the output shaft 4 of the gear box Ib is a ball coupling 9. (see the detail in FIG. 4). The ball coupling 9 is fitted with a sleeve 9a controlled manually by shifting in axial direction, the said sleeve 9a being blocked against movement in the locked position by means of a compression spring 9b and balls 9c movable in the direction perpendicular to the axis of the output shaft 4 of gear box Ib and partially sunk into the groove 1a of the drive shaft 1 blocked against movement with the sleeve 9a in its locked position. The torque is transferred via the groove connection between the output shaft 4 and the drive shaft 1.

[0043] The element for the repeatable connection and disconnection of the splitting threaded cone 3 to the end stud 8 of the drive shaft 1 is a bayonet coupling 14 (see the detail in FIG. 6). The end stud 8 is provided with two rectangular projections 8a with a shape off set 8b, the said rectangular projections 8a having longitudinal symmetry axis perpendicular to its rotation axis and forming an angle of 180° between themselves, while the profile of the inlet opening 3a of the splitting threaded cone 3 is an offset of end stud cross-section in place of its rectangular projections 8a. The splitting threaded cone 3 has on the side near its base the inlet opening 3a provided with a recess 3b for insertion of the end stud 8. A flat annulus shaped spring 13 is inserted into the recess space, the said flat annulus shaped spring 13 being bent and secured against shift and rotation by means of two hooks 13a placed symmetrically in the circumference around the rotation axis in openings 3c of the splitting threaded cone 3. The bayonet coupling 14 is created by inserting the end stud 8 into the inlet opening 3a with the recess 3b of the splitting threaded cone 3. By turning the end stud 8 a little inside the body of the splitting threaded cone 3 by an angle ranging from 10° to 90° it becomes secured against an axial movement in the direction outward from its base and the rectangular projections 8a of the end stud 8 will get behind the offset edge of the inlet opening profile 3a of the splitting threaded cone 3 (see the detail in FIG. 7).

[0044] In the device in the exemplary embodiment the axis of the output shaft Ia1 of the engine Ia is perpendicular to the rotation axis of the output shaft 4 of the gear box Ib. In this case the said gear box Ib is both two as well as multi-gear one, the first up to n-th gear being formed by an indented belt drive 15 or a front gearwheels drive and the last gear by a bevel gear train 16. With the crown gear 16a of the bevel gear 16 the hollow output shaft 4 of the gear box Ib is connected.

[0045] The bevel gear 16 inserted into the gear box Ib is self-locking and the shaft of the pinion gear 16b of the bevel gear 16 passes along the crown gear 16a while bearings 17 for placement of the pinion gear 16b are located on both sides of the crown gear 16a.

[0046] A firm, collapsible or demountable anti-torque bar (stop) 10 is connected to the carrier structure of the power unit I or the auxiliary gear box Ib, a part of which is also the first handle 21 for elimination of the reaction torque produced in operation of the work tool II and directed toward the operator's left hand. The longitudinal axis of the anti-torque bar (stop) 10 in the horizontal position is perpendicular or from the perpendicular axis deviated by an angle less than 30° with respect to the rotation axis of the output shaft 4 of the gear box Ib and the distance of the anti-torque bar (stop) 10 remotest point from the rotation axis of work tool II is 300 mm at minimum.

[0047] The power unit I is provided with the second handle 11 complete with engine Ia rotation controller, the longitudinal axis of which is parallel to the axis of the work tool II.

[0048] The thread Ib profile on the outer circumference of drive shaft 1 of the work tool II is trapezoidal one or has a profile enabling circulation of the balls 20 between the thread 1b on the outer circumference of the drive shaft 1 and the nut 5 in case a screw known as a ball screw is used.

[0049] Surface roughness of the thread profile 3d of the splitting threaded cone 3 (see FIG. 7) is less than Ra 0.4 μm.

[0050] A tube 18 for supply of lubricating oil to the thread 3d surface of the splitting threaded cone 3 runs through the hollow output shaft 4 of the power unit I, then inside the hollow drive shaft 1 and through the cavity around the central axis of the splitting threaded cone 3 (see FIG. 8). Ball or conical valves 19 for opening and closing of lubricating oil flow directed toward the thread 3d surface of the splitting threaded cone 3 are located inside the hollow output shaft 4 of the power unit I, on the entry part inside the hollow drive shaft 1 and in the hollow end stud 8. The lubricating oil is conveyed onto the thread 3d surface of the splitting threaded cone 3 by action of gravitational force.

[0051] The flow of the lubricating oil to the thread 3d surface of the splitting threaded cone 3 is opened by a shift of the splitting threaded cone 3 on the end stud 8 in the range of 0 to 10 mm in the direction of the power unit I by the effect of the device operator's force against the pressure of the flat ring 13 via the valve 19a located in the end stud 8 and closed by shift of the splitting threaded cone 3 in the opposite direction into its starting position by the effect of the force generated by the compressed flat spring 13 (see the detail in FIG. 9).

Example 2

[0052] In other variant of the exemplary embodiment of the portable wood log splitter according to the invention (see FIG. 2) the power unit I is formed by a building kit of the chain saw power unit Ic and the independent auxiliary gear box Ib, which is fixed in a dismantable way onto the flange Ic1 of the chain saw cutting blade. In this variant the anti-torque bar (stop) 10, a part of which is also the first handle 21, is connected firmly with the independent auxiliary gear box Ib.

[0053] Further elements and components of the device are designed identically with Example 1.

Example 3

[0054] In another arrangement of the portable wood log splitter according to the invention the axis of the output shaft of the engine Ia is parallel to rotation axis of the output shaft 4 of the gear box Ib. In this case, the said gear box Ib is multi-gear one while the first and the last gear are formed with front gearwheels or can be arranged as a planet one.

[0055] Further elements and components of the device are designed identically with Example 1.

LIST OF REFERENCE SIGNS (REFERENCE NUMBERS)

[0056] I power unit [0057] II work tool [0058] Ia engine [0059] Ib gear box [0060] Ic chain saw power unit [0061] Ic1 chain saw cutting blade flange [0062] 1 drive shaft [0063] 1a groove [0064] 1b drive shaft thread [0065] 2 spreading mechanism [0066] 3 splitting threaded cone [0067] 3a cone inlet opening [0068] 3b threaded cone recess [0069] 3c threaded cone opening [0070] 3d cone thread profile [0071] 4 gear box output shaft [0072] 5 nut [0073] 6 toothed disc [0074] 7 freely rotating circular disc [0075] 8 end stud [0076] 8a rectangular projection [0077] 8b shape off set [0078] 9 ball coupling [0079] 9a sleeve [0080] 9b compression spring [0081] 9c coupling balls [0082] 10 anti-torque bar (stop) [0083] 11 second handle [0084] 12 telescopic spiral spring [0085] 13 flat spring [0086] 13a flat spring hooks [0087] 14 bayonet coupling [0088] 15 belt drive [0089] 16 bevel gear [0090] 16a crown gear [0091] 16b pinion gear shaft [0092] 17 bearing [0093] 18 tube [0094] 19 ball valve [0095] 19a ball valve in the end stud [0096] 20 balls [0097] 21 first handle

[0098] It is noted that the terms “substantially” and “about” and “generally” may be utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. These terms are also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.

[0099] The foregoing invention has been described in accordance with the relevant legal standards, thus the description is exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiment may become apparent to those skilled in the art and fall within the scope of the invention.