Log splitting head

A log splitting head comprising a baseplate, first and second vertical cutting plates opposed and spaced from each other and mounted to and perpendicular with the baseplate, each including a cutting edge, a horizontal cutting plate mounted to and supported by the first and second cutting plates, and also including a cutting edge, and means for securing the baseplate to the main frame of a log splitting machine.

BACKGROUND OF THE INVENTION 
(1) Field of the Invention 
This invention pertains to log splitting devices and more particularly to a 
log splitting head which may be attached to the main frame of a log 
splitting machine. 
(2) Description of the Prior Art 
With the onset of the present energy crisis, many people are utilizing wood 
as an alternate energy source. The wood is burned in fireplaces or in a 
variety of wood burning stoves to generate heat. For ease of placing the 
wood in the stove or fireplace and for a constant burn, it is desirable 
that the wood used be of uniform size. Prior log splitting heads do not 
produce wood with this desired uniformity. 
Many devices have been used in the past for splitting logs. The most common 
is the standard wedge which is driven into a log by a sledgehammer and 
splits the log in two. Variations on the standard wedge have been made 
which split the log into more than two pieces. See, for example, U.S. Pat. 
No. 4,209,046. 
When splitting large numbers of logs, it is quite common to use a log 
splitting machine with a power actuated ram. The log to be split is placed 
in the machine and the ram forces the log up against a splitting wedge or 
splitting head. U.S. Pat. Nos. 3,862,651; 4,157,105; 4,176,696 and 
4,236,556 are exemplary of such machines. Often these machines have a 
fixed head permanently mounted to the machine and provide for only 
splitting the logs in half. In U.S. Pat. No. 4,157,105, the splitting head 
may be enlarged to split various sized logs in half. 
The head in U.S. Pat. No. 3,802,651 includes a vertical cutting wedge as 
well as a horizontal cutting wedge. With this head, a log may be split 
into quarters with one pass through the head. Also, the horizontal cutting 
wedge is hydraulically adjustable to accommodate logs of varying diameter. 
However, the size of the quartered logs will not be uniform but will vary 
directly with the size of the initial log. Further, this head is 
permanently attached to the log splitting machine and requires a hydraulic 
system to adjust the horizontal wedge and thus handle different sized 
logs. U.S. Pat. No. 4,176,696 shows a similar head. 
Accordingly, it is an object of the present invention to provide a log 
splitting head which can be used in combination with a power actuated ram. 
It is a further object of the present invention to provide a log splitting 
head which can accommodate logs of varying size with minimal moving parts 
and which provides for simultaneous multiple splits. 
It is yet another object of the present invention to provide a log 
splitting head which splits logs into sections which are especially 
uniform and neat regardless of the initial size of the log. 
SUMMARY OF THE INVENTION 
I have invented a log splitting head comprising a baseplate, first and 
second vertical cutting plates opposed and spaced from each other and 
mounted to and perpendicular with the baseplate, each including a cutting 
edge, a horizontal cutting plate mounted to and supported by the first and 
second cutting plates, and also including a cutting edge, and means for 
securing the baseplate to the main frame of a log splitting machine. 
Preferably the horizontal edge leads the vertical cutting edges, the 
baseplate has a beveled edge, the horizontal cutting plate slopes upward 
and away from its cutting edge, and the distance between the vertical 
cutting plates increases as the distance from their cutting edges 
increases. The horizontal cutting plate may be detachably mounted to the 
vertical cutting plates. I have also invented the above log splitting head 
in combination with a log splitting machine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to FIGS. 1-4, there is shown a log splitting head 10 in 
accordance with the present invention. The log splitting head 10 includes 
a baseplate 12, first and second support plates 14, 16 each mounted along 
one edge to one planar surface of the baseplate 12, first and second 
vertical cutting plates 18, 20 each mounted along one edge to the other 
planar surface of the baseplate 12, and a horizontal cutting plate 22 
mounted to and supported by first and second vertical cutting plates 18, 
20. The vertical cutting plates 18, 20 are opposed and spaced apart from 
each other and are oriented substantially perpendicular with, but set back 
from, the front edge 38 of the baseplate 12. The support plates 14, 16 are 
mounted perpendicular to the other planar surface of the baseplate 12, are 
parallel with each other and are spaced apart a sufficient distance to 
accommodate the log splitting machine main frame 24 upon which the log 
splitting head 10 is mounted. 
The support plates 14, 16 are secured to the main frame 24 by means of a 
removable pin 26 which passes between the support plates 14, 16 
immediately beneath the main frame 24. The pin 26 is held in place by a 
retainer 28 such as a cotter pin or the like. One or more blocks 30 may be 
mounted on the main frame 24 between the support plates 14, 16. These 
blocks 30 have holes to accommodate the pin 26 and provide additional 
support and stability for the log splitting head 10 when mounted. 
The front edge of the horizontal cutting plate 22 is beveled to provide a 
sharp horizontal cutting edge 32. Similarly, the front edges of the 
vertical cutting plates 18, 20 are beveled to provide sharp first and 
second vertical cutting edges 34, 36. Because the logs to be split move 
along the surface of the main frame 24, the front edge 38 of the baseplate 
12 is beveled to allow a log to slide freely up to the horizontal and 
vertical cutting plates 18, 20, 22 without catching. All of the cutting 
plates are oriented with their cutting edges facing the front edge 38 of 
the baseplate 12 and in cross section resemble the shape of the Greek 
letter "pi". 
As is shown in FIGS. 2 and 3, the horizontal cutting edge 32 is set back 
behind the beveled front edge 38 of the baseplate 12. Further, the 
horizontal cutting edge 32 leads the vertical cutting edges 34, 36, i.e., 
the cutting edges 34, 36 of the vertical cutting plates 18, 20 are set 
back behind the cutting edge 32 of the horizontal cutting plate 22. In 
this manner, the log is split not all at once, but in successive 
stages--the horizontal split is made first and then the vertical split. By 
this arrangement less power is needed to force a log against the head 10 
than would be needed if the cutting edges of the cutting plates were all 
on the same line, thus enabling a smaller log splitting machine to perform 
comparably to larger machines with less efficient splitting heads. It is 
to be understood that the cutting edges may be arranged in a variety of 
positions but preferably they are staggered to provide log splits in 
successive stages. 
The horizontal cutting plate 22 is preferably inclined along an upward 
slope away from the horizontal cutting edge 32 with the cutting edge 32 
being at the lowest level. The vertical cutting plates 18, 20 preferably 
diverge, while remaining perpendicular to the baseplate 12, providing for 
an increasing distance between the plates 18, 20 from their cutting edges 
34, 36 to their rear edges 40, 42. In this manner, a split portion of a 
log passing between the vertical cutting plates 18, 20 will not touch the 
surface of either the vertical or the horizontal cutting plates. The 
remaining portions of the split log passing beneath the horizontal cutting 
plate 22 will pass along the vertical cutting plates 18, 20, but will not 
touch the horizontal cutting plate 22 once the cut has been made. In this 
manner frictional drag is substantially reduced, further reducing the 
necessary power from the log splitting machine. Also, the log will not 
become wedged within the splitting head 10 and the possibility of damage 
to the cutting plates from excessive pressure from the log is reduced or 
eliminated. 
The log splitting head 10 of the present invention is easily mounted onto 
the main frame 24 of a log splitting machine. The pin 26 is removed from 
the support plates 14, 16, the head 10 is placed on the main frame 24 with 
the support plates 14, 16 straddling the main frame 24 and the baseplate 
12 resting on the main frame 24, and the pin 26 is reinserted through the 
support plates 14, 16, the blocks 30 and retained with the retainer 28. To 
prevent backward movement of the log splitting head 10, a thrust plate 44 
may be secured to the main frame 24 immediately adjacent the baseplate 12 
by welding or the like. 
Preferably the support plates 14, 16, baseplate 12, the vertical cutting 
plates 18, 20 and the horizontal cutting plate 22 are made of steel and 
are fastened together by welding or the like. However, as an alternate 
embodiment shown in FIG. 5, the horizontal cutting plate 22 may be 
detachably mounted to the vertical cutting plates 18, 20 by bolts 19 and 
nuts 21, or the like, and removed in the event of jamming of cut logs 
between the vertical cutting edges 34, 36. A wedge-shaped section 23 with 
openings 25 for the bolts 19 and nuts 21 may be mounted to the top of the 
horizontal cutting plate 22. This section 23 removes interference from the 
protrusion of the bolts 19 and nuts 21 and provides for a greater incline 
along the horizontal cutting plate 22. 
The horizontal cutting plate 22 shown in FIG. 5 can also be detached 
automatically by using nuts 21 made of soft aluminum. Such nuts 21 will 
shear off of the bolts 19 in the event that upward forces on the 
horizontal cutting plate 22 need to be dissipated. Alternately, shear pins 
may be used instead of the soft aluminum nuts. Also, stiff springs may be 
used to secure the horizontal cutting plate 22 to the vertical cutting 
plates 18, 20. 
The operation of the log splitting head 10 in splitting a typical log 45 is 
illustrated in FIGS. 6 and 7. The log 45 is moved along the main frame 24 
and forced up against the log splitting head 10 by a power actuated ram 
46. The log moves up the front edge 38 of the baseplate 12 and makes 
contact with the cutting edge 32 of the horizontal cutting plate 22 which 
begins splitting the log in two. The upper portion 48 of the log continues 
to move on top of the horizontal cutting plate 22. The lower portion of 
the log then makes contact with the cutting edges 34, 36 of the vertical 
cutting plates 18, 20 which split this portion into three smaller sections 
50, 52, 54. The ram 40 continues to move the log until it is split along 
its entire length and the smaller sections 50, 52, 54 are removed. The ram 
is then retracted, the upper portion 48 of the log moved back down the 
horizontal cutting plate 22 and onto the main frame 24, and the splitting 
process is repeated. 
It can be seen in FIGS. 6 and 7 that the lower portion of the log 50, 52, 
54 does not further touch the horizontal cutting plate 22 once the 
horizontal split has been made. A series of spaces 49, 51, 53 are formed 
by the inclined slope of the horizontal cutting plate 22. Further, as can 
be appreciated in FIG. 6, the middle portion 52 of the lower portion of 
the split log does not make any contact with the vertical cutting plates 
18, 20 once the vertical splits have been made and will not become jammed 
in this area. FIG. 6 also shows the blocks 30 secured against the bottom 
of the main frame 24. 
FIGS. 8-12 illustrate schematically how various sized logs may be split 
into uniform sections using one size of a log splitting head 10 made in 
accordance with the present invention with one or more passes through the 
head 10 as is needed. Each of these drawings includes, for purposes of 
clarity, only the baseplate 12, vertical cutting plates 18, 20 and 
horizontal cutting plate 22 of the log splitting head 10, as well as the 
log to be split. While the logs are shown in circular cross section, it is 
to be appreciated that wood of any cross section may be advantageously 
split using tthe log splitting head 10 of the present invention. 
FIG. 8 shows a small log 56 placed against one of the vertical cutting 
plates 18. Such a log will only need one pass through the cutting head to 
be adequately split into two identical sections. A slightly larger log 58 
shown in FIG. 9 can be split in one pass with the horizontal cutting plate 
22 and one of the vertical cutting plates 18. A larger log 60 shown in 
FIGS. 10A and 10B can be split in two passes. The log 60 is first split in 
three sections as shown in FIG. 10A, and then the remaining upper portion 
62 is split in half as shown in FIG. 10B. The sequential steps in 
splitting a larger log 64 and using all of the cutting plates is 
illustrated in FIGS. 11A, 11B, and 11C for a three pass operation. In the 
first pass, the lower portion of the log 64 is split into three smaller 
sections 67, 68, 69, which are ejected from the head. The remaining upper 
portion of the log 70 is brought back into position and split, and this 
procedure is repeated until the entire log 64 is split into small, 
approximately uniform sized sections. FIGS. 12A, 12B, 12C, 12D, and 12E 
illustrate the steps required to split a larger log 66 in five passes. 
After the first split is made, the log 66 is rotated 90.degree. to the 
left for the remaining four passes. 
It can be seen that the logs shown in FIGS. 8-12 will be split into 
approximately uniform sections, each no larger than the section which 
passes between the vertical cutting plates 18, 20 and beneath the 
horizontal cutting plate 22. The number of passes required through the log 
splitting head 10 will be determined by the diameter of the log being 
split as can be appreciated in FIGS. 8-12. 
Although the invention has been described in detail above, it is only to be 
limited so far as is set forth in the accompanying claims.