Note: Descriptions are shown in the official language in which they were submitted.
3131
1 The present invention provides an economical apparatus
for splitting logs that is particularly suitable for home use.
Mechanical log splitters have been in use for commercial
applications, but no completely satisfactory device has been
available for the individual who desires to split logs for his
own use. The available commercial devices are both expensive
and hazardous to use making them unacceptable for home use.
Such splitters as have been made available at a price to qualify
them for home use have either been ineffective, awkward to use
or excessively hazardous to operate.
It is an object of this invention to provide a log
splitter that is easily operated, either manually or power-driven,
and which creates minimum hazard in its use.
It is another object to provide such a log splitter
having a wedge with a single point that engages the end of the
log to be split.
It is still another object to provide such a device
which supports the log only in the ~entral area of the bottom
surface.
Another object is to provide a log splitter having a
pointed splitting wedge having converging edges forming a point
and converging surfaces terminating at the same point.
Another object is to provide à vertical log splitter
having a movable lower support for receiving the bottom end of
a log to be split and an upper splitting wedge secured to a
vertical frame by a quick-release hand-operated lock.
Still another object is to provide a log splitter in
which vertical ~orces are applied to split the log without the
generation of substantial lateral forces.
These and other objects will be in part pointed out in
-- 1 --
l~LG3~31
1 and in part apparent from the following description of a preferred
embodiment of the invention considered in conjunction with the
accompanying drawings, in which:
Figure 1 is an elevational view of a log splitter
embodying the invention;
Figure 2 is a sectional view taken along line 2-2 of
Figure l;
Figure 3 is a plan view of a locking member used in
the log splitter;
Figure 4 is an elevational view of a power drive
attached to the log splitter jack;
Figure 5 is a plan view of the drive of Figure 4;
Figure 6 is a partial sectional view of the drive taken
along line 6-6 of Figure 7; and
Figure 7 is a partial sectional view taken along line
7-7 of Figure 6.
The log to be split is supported in a vertical
position by an I-beam 2 having an upper projection 4 that engages
the central area of the bottom of the log. The log is split by
a wedge, generally indicated at 6 in Figures 1 and 2, having a
point 8 that makes initial contact with the upper end of the log.
- The vertical design of the log splitter is advantageous in that
it permits logs of different diameters to be centered readily on
the projection 4 and. the wedge point 8. Such centering i5
difficult or impossible with splitters in which the log is
mounted in a horizontal position.
In order to split the log with minimum force and
minimum stroke, the wedge 6 is tapered in two directions. From
a front view as shown in Figure 1, the point is formed by two
linear tapered edges 10 and 12. The wedge 6 is also tapered in
-- 2 --
11(~3131
the plane at 90 degrees from the front view of Figure 1 as shown
in Figure 2. The wedge 6 is formed of two steel plates 14 and 16
which are curved on a radius as indicated at 18, pos-itioned to
form an acute angle, and welded together near the bottom edge
to form a solid blade portion 20 that has a short linear taper
that terminates in an edge along the bottom of the wedge and joins
the radii 18 along its top. This double-tapered wedge construction
requires less force to cause initial penetration than would a
conventional wedge that makes a line contact with the end of the
log and it also causes the log to split with less penetration
than would be required by a conventional single-taper wedge. As
used herein, the term double-tapered wedge means a wedge havin~
two side surfaces that form an acute angle and which meet along
two edges that, in another plane, form an acute angle with an
apex at an extreme point of the wedge. The wedge may be formed
in any desired manner, as by two separate parts welded together,
or it may be cast as a single piece and machined to the desired
dimensions.
As shown at 24, the plates 14 and 16 are welded along
their upper edges to a carriage 22 which is slidably positioned on
two vertical standards, formed of steel pipe, by means of two
cylindrical guides 30 and 32, of square cross section, arranged
to slide vertically on the standards 26 and 28. The wedge is
manually ad~usted vertically by means of a handle 34 secured to
the carriage 22 and locked in position by two quick-release clamps,
generally indicated at 36 and 38. These clamps are normally
maintained in locked position by two generally U-shaped leaf
springs 40 and 42 which are secured at one end area to the
carriage 22 with the free upper end of each spring e~erting an
upward force on a stack of five locking members 44. Each of
11(~313i
1 the locking members is a flat steel plate having an enlarged
rectangular end portion 46 (Figure 3) with a central hole having
a diameter slightly greater than the outside diameter of the
standards 26 and 28 so that when the locking member is canted
with respect to the standard, it binds against the standard and
is locked in position. Each of the locking members passes
through a rectangular opening 45 in a fulcrum member 47 and pivots
about the upper surface of the opening 45. To prevent the
scoring of the standards 26 and 28 by the clamping action from
interfering with the free sliding movement of the guides 30 and
32, each of the openings in the locking members is relieved, in
the area adjacent the outer surface of the standard which passes
through it, by a notch 50. The clamping force is therefore
applied to areas indicated at 52 in Figure 3. If this clamping
action scores the standards 26 and 28, it is of little consequence
because the score marks will occur in portions of the standards
passing through the corner sections of the rectangular guides that
do not engage the surfaces of the round standards.
When the handle 34 is grasped, the end portions of the
locking members 44 are enclosed in the grasp and moved against
the force of the leaf springs 4~ and 42 into a generally hori-
zontal position releasing the lock on the standards and permitting
the entire carriage and wedge assembly to be moved vertically.
Upon release of the handle 34, the locks 36 and 38 re-engage
the standards and secure the wedge assembly in position, locking
it securely against any upward force.
In use, the wedge assembly is lifted to its highest
position, the movement being limited by two top caps 53 threaded
onto the standards 26 and 28, and the lGg is placed vertically
on the projection 4 and held in that position while the carriage
-- 4 --
11(~3i31
g and wedge assembly is lowered so that -the wedge point 8 engages
the upper surface of the log and holds it in position. The
projection 4, ma~ing essentially point contact with the log,
prevents the application of a transverse force to logs having
an angular lower end surface when the splitting force is applied.
The projection 4, which may be of any cross-sectional shape, has
a surface area small in comparison with the end area of the
smallest log to be split and may, typically, have between one and
eight square inches, but must of course be functionally large
enough to maintain essentially point contact no matter what type of
wood is being split. The point contact of the wedge on the
upper end also serves a similar function and prevents the
development of lateral forces on logs having an angular end
surface. This alignment of forces allows application of large
splitting forces without generating bending moments, permitting
the use of a lighter and simpler frame than would otherwise be
required.
The design of the log splitter makes it possible to
split logs with a diameter larger than the distance between the
2~ two standards 26 and 28, by placing the log off-center between
the projection 4 and the wedge point 8 and reducing the diameter
o the log by multiple splits.
The I-beam 2 is slidably supported on the standards 26
and 28 by two cylindrical guides 54 and 56, also of rectangular
cross section, which fit around the standards. The guides 54
and 56 are long enough to permit relatively free movement on
the standards in spite o~ any expected twisting or off-center
forces on the I-beam 2.
With the log positioned between the I-beam 2 and
3~ the wedge 6, the splitting action is produced by forcing the
beam upwardly and driving the log into the wedge 6. The necessary
force is conveniently produced by a hydraulic jac~, generally
.: ~
~Q3131
1 indicated at 60, which may be an ordinary automobile jack of
the kind intended to be operated by foot action.
The hydraulic jack 60 rests on a supporting I-beam 62
which in turn is supported by two parallel steel channels 64
that serve as a stable base for the splitting unit. The movable
ram 66 of the jack 60 abuts the underside of the I-beam 62 and
advantageously may be positioned in a recess so the ram will not
accidentally be dislodged during use.
The jack 60 has a handle 68 that is intended for
vertical reciprocal movement by foot action. When the handle is
forced down, the conventional cam mechanism operates the jack in
the usual manner, the handle then being returned, by a spring 70,
to its upward position upon release of the downward force.
Movement of the handle forces the I-beam upwardly to produce the
compressive force between the log and the wedge 6.
When the log has been split, the hydraulic pressure
in the jack 60 is released by a foot-operated lever 72 and the
I-beam 2 is returned to its lowermost position by two tension
springs 74 and 76 extending between the two beams 2 and 62.
~0 For reasons of economy and to minimize the overall
height of the structure, the jack 60 has a relatively short stroke,
for example, about six inches, which is sufficient with the
wedge structure already described to split most logs. However,
if a longer stroke is needed to complete the splitting action,
the jack 60 is allowed to return to its retracted position, by
operation of the lever 72, while the clamps 36 and 38 are held in
release position. The entire log-holding assembly is then moved
downwardly so that the full stroke of the jack 60 is again
available to drive the wedge 6 farther into the log. The log
splitting apparatus described is particularly safe to operate
-- 6 --
3~31
because of the slow movement of the parts and the absence of
lateral forces.
In order that the log splitter may be easily moved from
one location to another, a pair of wheels 75 are attached near
the ends of the base channels 64. By tilting the entire splitter
so that it is balanced on the wheels 75, i~ can be moved readily
in the manner of a conventional hand truck.
The required manual labour is reduced and the speed of
the splitting operation is increased by the use of a power drive.
10 The electric drive system shown in Figures 4-7 is particularly
well adapted for this purpose. It is attached to the jack 60 with
a minimum of modifications so that it is possible to add the
electric drive to the same jack that is used for manual operation.
A universal electric motor 77 is coupled to a speed-
reducin~ transmission, generally indicated at 78, which may be
of any desired type, such as the one described in my U.S.Patent
3,574,489. The motor and speed reducing transmission are mounted
on the jack 60 by a pin 79 extending between the mounting
brackets 80 and 82 and through a mounting collar 84 on the
20 housing of the motor and speed reducing unit. The pin 79 is used
as a pivotal mounting for the jack handle 68 in the manually-
operated embodiment. The housing is also secured to the jack b~
an arm 86 extending between the housing of the speed reducer and
a collar 88 around the body of the jack.
To produce the necessary reciprocating motion, the
driven shaft 90 from the speed reducer 78 is secured to a drive
disk 92 mounted eccentrically on the shaft 90 and which is
surrounded by a sliding collar assembly 94. This collar assembly
includes a pair of spaced arms 96 connected by a cross pin 98
30 which is maintained in abutment with the end of the jack piston 100
~1~ 313~
1 by a U-shaped clip 102. Rotation of the shaft 90 produces a
reciprocating motion of the piston 100 and causes the ram 66
of the jack to move upwardly. The pressure release of the jac~
is controlled in the same manner as with the manually-operated
unit.
The electric drive unit is mounted directly on the
jack 60 and may be removed as an integral part with the jack from
the remainder of the log splitter assembly. Thus, the electrically
driven jack may be used for a wide variety of applications where
economy is important and it is desired to take advantage of the
low cost of commercial hydraulic jacks. It is to be noted that
the motor drive unit can be used to convert any standard commercial
hand-operated hydraulic pump or self-contained lifting jack into
a power-operated unit at a fraction of the cost of conventional
systems. No modification of the pump is re~uired and there are
no hoses or separate valving systems to be provided. The drive
configuration with its linkage method of attachment to the
pump is simple, effective, and requires no precision machining.
From the foregoing description of particular embodiments
of my invention it will be apparent that my invention is well
adapted to meet the ends and objects herein set forth, to be
economically manufactured, and that it is subject to a wide
variety of modifications to best adapt it for each intended
application.
-- 8 --
., .
, " ,
.
~-
