Log splitter with gear rack drive

A log splitter of the horizontal track, upstanding blade, reciprocating carriage type is driven by mechanical rather than hydraulic mechanism to reduce cost and weight and breakage. Instead of crank arms, a gear rack and spur gear system is provided, there being a large drive gear meshed with the spur gear, and a small diameter, light weight flywheel on the motor drive shaft, the mechanical advantage being sixteen to one or more. A safety overload kick-off is incorporated into the control mechanism for automatic actuation when a log presents unusual resistance to splitting.

BACKGROUND OF THE INVENTION 
There have been many different structures proposed for splitting logs, some 
horizontal, some vertical, some driven by hydraulic mechanism and some 
driven by mechanical mechanism. Usually the mechanical mechanism has 
involved a fixed abutment and a pusher blade movable along a horizontal 
track, or beam by means of crank arms or pitman, to push the movable blade 
through the fixed log for splitting. 
Exemplary of such devices are U.S. Pat. No. Re. 13221 to Power of Mar. 21, 
1911, U.S. Pat. No. 1,231,525 to Hauberg of June 26, 1917, U.S. Pat. No. 
1,666,795 to Schmidt of Aug. 17, 1928, and U.S. Pat. No. 2,446,585 to 
Hanners of Aug. 10, 1948. 
Log splitting mechanisms using a horizontal track, or beam, a fixed blade 
at one end of the beam and a log pushing carriage movable toward the blade 
by hydraulic mechanism are taught in U.S. Pat. No. 3,280,864 to Spanenberg 
of Oct. 25, 1966, U.S. Pat. No. 3,760,854 to Worthington of Sept. 25, 1973 
and many other patents. 
While all of the log splitting devices of these, and other patents, 
probably perform their function adequately, the types which have reached 
the present day market appear to be relatively costly, slow moving and 
subject to breakage under continual use. 
SUMMARY OF THIS INVENTION 
In this invention a log splitter is disclosed which can be easily moved 
about horizontally on a set of trailer wheels and which requires few 
machined parts but rather requires only relatively low cost, rugged, long 
lasting parts. The splitter comprises an elongated track, in the form of a 
horizontal I beam, a blade removably affixed in upstanding position at one 
end of the track a log pushing carriage slideable on, and retained on the 
track and gear rack and spur gear, motor driven mechanism for advancing 
the carriage toward the blade. 
A large diameter, heavy fly wheel may be used in permanent installations 
but preferably mechanical advantage is obtained by a large low cost gear 
driving the spur gear shaft and a small diameter gear meshed with the 
teeth of the large gear and fast on the motor drive shaft together with a 
small, fly wheel of lesser weight. 
Control is obtained by rotating the spur gear continuously and 
unidirectionally while normally poising the gear rack out of mesh with the 
spur gear by a coil spring. Pressure on one end of a pivoted hand lever 
moves the rack into mesh with the gear to advance the pusher carriage to 
split the log. 
The elongated gear rack provides considerably longer push on the carriage 
than can be obtained by crank arms of reasonable length and overload 
kick-off mechanism is incorporated into the control by way of a cam, cam 
follower spring and roll.

DESCRIPTION OF A PREFERRED EMBODIMENT 
The log splitter 20 of the invention includes the horizontal, 
log-supporting track 21, which is preferably a steel I beam, and which 
constitutes the support for a log 22, to be split by the device. The track 
21 is supported on the bases 23 by posts 24 and 25 but can be mounted on 
trailer wheels, if desired, in a manner well known in the art. 
A splitter blade 27 is fixed in upstanding position, at one end 28 of the 
track, the blade having a sharp cutting edge 29, and being easily 
removable and replaceable when worn by bolts 31. Shear pins 32 are also 
provided to yield under extreme resistance to advance of the log by the 
carriage. 
The log pusher carriage 33 is slidably mounted on the upper rail 34 of 
steel, I-beam, track 21 with flanges 35 for retainment and an upstanding 
pusher plate 36 for engaging the adjacent end of a log 22. 
Power means 37 is provided for driving the carriage 33 to push a log 22 to 
be split by the sharp edge 29 of the blade 27 and to travel the carriage 
far enough to clear the split portions of the log in a direction end-wise 
of the rail for a substantial distance. 
Power means 37 includes at least one spur gear 38 fast on a shaft 39 
supported in a pair of spaced bearing blocks 41 and 42 on the upper rail 
34 of track 21. Means 37 also includes an elongated gear rack 43 having 
one end 44 pivoted at 45 to the carriage 33 and having teeth 46 along the 
underface 47 normally poised proximate, but out of mesh with, the teeth 48 
of the spur gear by the coil spring 49. 
Control mechanism 51 is provided to selectively engage and disengage the 
gear rack teeth 48 with the spur gear teeth 46, and includes a lever 52 
pivoted at 53 to a bracket 54 affixed at the other end of track 21. The 
lever 52 includes a handle 55 above the pivot 53 and the other end 56 of 
the lever, when pivoted downwardly, contacts the upper face 57 of the gear 
rack to push it downward into mesh. A stop 58 is preferably provided for 
the lower end 56 of the lever 52. 
Upon engagement of the gear rack teeth with the unidirectionally rotating 
teeth of the spur gear, the gear rack is advanced over a long path of 
travel to split the log and discharge the pieces endwise for a 
considerable distance. The lever 52 tilts by the weight of the handle 55 
to lift the gear rack teeth out of mesh with the spur gear teeth, while a 
retraction spring 59 returns the gear rack and carriage ready for the next 
forward stroke. 
In the embodiment of FIGS. 1-3 the drive motor 61, which may be electric, 
or gasoline, has a drive shaft 62 with a small diameter, rubber faced 
roller 63 thereon, the motor being mounted on a pivoted, threadedly 
adjustable mounting plate 64 under track 21. The roller 63 frictionally 
engages the periphery 65 of the hollow, tubular rim 66 of a large diameter 
unusually heavy fly wheel 67 fast on spur gear shaft 39, and filled with 
cement or other heavy hardened material 68. 
In the preferred embodiment of FIG. 4, all of the parts of the log splitter 
20 remain the same as in the embodiment of FIGS. 1-3 except that the 
unusually heavy fly wheel 67 has been eliminated in favor of a large 
diameter, but much lighter, drive gear 71, which is driven by the small 
drive gear 72 fast on motor shaft 62, there being a small diameter fly 
wheel 73, of light weight, also fast on the motor drive shaft 62. The 
drive gear 71 is fast on the spur gear shaft 39 to produce a mechanical 
advantage of at least sixteen to one. 
Safety overload, kick-off means 74 is also included in the preferred 
embodiment of FIG. 4, consisting of a roller 75 rotatably mounted at the 
lower end 56 of the pivoted lever 52 of the control mechanism 51 and in 
rollable contact with the upper face 57 of gear rack 43. A cam follower 76 
and the roller 75 are spring based downwardly by coil spring 77 and 
yieldable upwardly under predetermined pressure from gear rack 42, due to 
resistance to splitting of the log, to cause the cam 78 to kickoff, or 
pivot, the lever 52 in the direction of the arrow to disengage the gear 
rack teeth 48 from the spur gear teeth 46.