US 3077214 A
Abstract available in
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Description (OCR text may contain errors)
Feb. 12, 1963 c. J. BRUKNER 3,077,214
LOG SPLITTER Filed Aug. 27, 1959 e Sheets-Sheet 1 FIG-1 IN VEN TOR.
CLAYTON J. BRUKNER ATTORNEYS Feb. 12, 1963 c. J. BRUKNER 3,077,
LOG SPLITTER Filed Aug. 27, 1959 6 Sheets-Sheet 2 INVEN TOR.
CLAYTON J. BRUKNER ATTORNEYS 6 Sheets-Sheet 3 C. J. BRUKNER LOG SPLITTER Feb. 12, 1963 Filed Aug. 27, 1959 E wm ATTORNEYS Feb. 12, 1963 c. .1. BRUKNER LOG SPLITTER 6 Sheets-Sheet 4 Filed Aug. 27, 1959 IN V EN TOR. CLAYTON J. BRUKNER rRETURN ATTORNEYS ENGINE Feb. 12, 1963 c. J. BRUKNER 3, 7 ,214
LOG SPLITTER Filed Aug. 27, 1959 6 Sheets-Sheet 5 IN VEN TOR.
CLAYTON J. BRUKNER ATTORNEYS Feb. 12, 1963 c. J. BRUKNER LOG SPLITTER 6 Sheets-Sheet 6 Filed. Aug. 27, 1959 FIG-l4 FIG-15 JNVENTOR. CLAYTON J. BRUKNER ATTORNEYS United States Patent ()fifice 3,0772% Patented Feb. 12, 19bit 3,677,214 L9G SPLITTER Qlayton .l. Bruhner, The Waco Aircraft Co., Troy, @hio Filed Aug. 27, 1959, Ser. No. 836,541 19 Claims. (Cl. 144-193) This invention relates to log splitting machines and more particularly to a hydraulically operated log splitter.
The hand splitting of logs is universally recognized as a tedious, back breaking job. It is also costly and time consuming to any business which finds it necessary to split logs as a step or part of a manufacturing operation, or in the production of an end item, such as firewood. The present invention provides a self-contained, mobile, hydraulic splitting machine which eliminates much of the manual labor involved in splitting wood. The ease by which the machine of the invention may be moved and its ability to split very dificult cross grain pieces, such as elm, combine a unique versatility with an ability to turn waste logs into profit. he log splitter of this invention is compact, and can be readily moved into location to split wood at tie site or" a fell. It can be operated by one man, on either a small or a large job, and is designed to use commonly available oil for the hydraulic fluid to eliminate the need for special supply considerations.
The preferred embodiment of the invention includes a longitudinally extending frame which combines the central structural member of the machine and the bed for the guided movement of the projected end of a driven ram. The self-contained hydraulic power generating equipment, including a hydraulic pump driven by motive power, is mounted adjacent one end of the bed. The relatively moving log splitting components, including a splitting wedge and the ram, are mounted in normally spaced relation to each other along the length of the bed. The frame is in turn mounted on a pair of road wheels which may be moved from a normally lowered road position into a raised position for lowering the bed of the machine nearer to the ground to facilitate the loading by rolling of heavy or large diameter logs onto the bed for splitting. A mechanical linkage to the ram operates to raise or lower the wheels, as desired, upon the extension of the ram along the bed.
The relatively movable piston ram and cylinder assembly includes inner and outer concentric cylinder portions for providing either high splitting speed with moderate splitting force or low speed with high force. The piston includes separate areas subject to the hydraulic pressures within the cylinder portions which are selectively subjected to hydraulic pressure through a selector valve arrangement. A hydraulic auto-shift device continuously senses the resistance of the log to splitting and operates a valve through an over-center mechanism to apply pres sure to the total piston area upon the occurrence of an unusually stubborn log or knot and for removing the pressure from a portion of such total area immediately upon the resumption of normal splitting resistance. The hydraulic arrangement through this simplified hydraulic control system provides for a continuously filled working and standby cylinder portion to the end that no delay is encountered when shifting from moderate force, high speed to full force, low speed operation.
' The splitter includes an adjustable back stop for adjusting the length of the piston return stroke to eliminate lost piston motion in the splitting of short logs. Also, provision is made for effecting either semi-automatic operation, wherein the piston automatically retracts upon the completion of the splitting stroke, or fully automatic operation wherein the piston is repeatedly cycled to perform one working stroke after another, so that an operator need not touch the controls and is free to concentrate upon the loading of logs onto the bed of the machine, and the removal of the split portions. The movement of the control lever is connected to operate an engine throttle device which causes the engine to drive the pump at substantially full governed rpm. in the power stroke and to return the engine to a fuel saving idle speed upon the completion of the outward power stroke.
The frame of the splitter includes an attachment by which a platform may be fixed thereto to extend on either side of the machine. This platform has been found useful in reducing the height for lifting and removing the split portions of the log.
The invention accordingly numbers among its objects the pro-vision of a hydraulic log splitter characterized by some or all of the features outlined above, and other objects and advantages of the invention will be apparent from the following description, the accompanying drawlugs and the appended claims.
In the drawings- FIG. 1 is a perspective view of the splitter from the right side of the machine;
FIG. 2 is a partial perspective view of the splitter from the left side;
FIG. 3 is a partially broken away elevational view of the frame showing the relation of the hydraulic motor to the frame and the wedge assembly;
FIG. 4 is a plan view of the splitting wedge assembly of FIG. 3;
FIG. 5 is an end view of the frame showing the mounting arrangement for the cylinder head of the hydraulic motor;
PEG. 6 is a partially broken away elevation view of the frame and hydraulic components from the right side of the splitter;
FIG. 7 is a partially broken away plan view looking down upon the components of FIG. 6;
FIG. 8 is a section through the ram and ram guide taken generally along line 8l% of FIG. 3;
PEG. 9 is an elevational fragment of the hand lever mechanism in the moved position with respect to the position shown in FIG. 6;
FIG. 10 is a hydraulic diagram of the log splitter;
FIG. 11 is a partially broken away elevation view of the splitter showing the mechanism for raising and lowering the frame with respect to the road wheels and the adjustable back stop;
FIG. 12 is a fragmentary view of the mechanism of FIG. 11 in a moved position;
FIG. 13 is a fragmentary detail of the raising and lowering mechanism taken generally along lines lit-13 of FIG. 12;
FIG. 14 is a section through the auto-shift cylinder assembly taken generally along line 14l4 of FIG. 7;
FIG. 15 is a plan view of a platform attachment for supporting the split portions of the logs off of the ground;
FlG. 16 is a fragmentary elevational view of a portion of the bed showing an adjustable stroke repeater block attachment to the stop link for effecting fully automatic operation; and
FIG. 17 is an end view of the attachment of FIG. 16.
Referring to the drawings, which illustrate a preferred embodiment of the invention, a log splitter is shown in FIGS. 1 and 2 as including a generally horizontally disposed longitudinally extending frame indicated generally atZtl. The frame 2t) is generally rectangular in section and forms a substantially horizontal bed generally indicated at 22 for receiving logs to be split by the opera tion of the machine. Two transverse sills 23 and 2dattached to one end of the frame 20 support an oil supply tank 25 on one side of the frame 20 and an enginepump unit designated at 26 on the other side. Bearlugs 27 rotatably attach axle or rockshaft 28 between 3 the sills 23, 24 at three points and a road pan 29 provides basic protection, especially when the machine is in lowered position while moving.
A pair of road wheels 3% are positioned at opposite sides of the pan 29 and are each mounted to the rock shaft 28 on a pair of supporting levers 31 in offset leading relation to each end of the rockshaft The frame 2t), and therefore the splitting bed 22, may assume a normally raised position for transporting the splitter, as shown in H68. 1 and 2, or may be lowered on the wheels to place the bed 22 nearer to the ground to fa cilitate the rolling of large diameter logs onto the bed. The movement between the raised and lowered positions is accomplished by rotating the rockshaft 28 and the levers 31 either to lift or lower the wheels with respect to the frame 2% A conventional hitch assembly 32 is fixed to the front end of the frame 2% remote from the pan 29 by means of which the splitter may be attached for movement behind a vehicle. The pan 29 is sled-like in configuration with sloping front and rear portions, and the splitter may be skidded on the pan over rough terrain or over snow with the wheels raised, if desired.
Relatively movable hydraulic log splitting apparatus is mounted in spaced relation along the bed 22 of the frame 2%. The apparatus includes an open ended hydraulic cylinder motor 33 longitudinally fixedly mounted upon the bed 22 and a piston driven ram tube 34 arranged for telescopic movement within the motor 33 and for longitudinal extended movement upon the splitter bed. The splitting apparatus also includes a log splitting wedge assembly 35 and in spaced apart relation to the motor 33 opposite the open end thereof.
The engine-pump unit 26 for supplying operating power to the motor 33 includes a gasoline engine 3:8 mounted on the sill 24 at one side of the motor 33. A pump frame 39 is mounted to the face of the engine 3% and supports a hydraulic gear pump 4% in direct driven relation to the shaft of the engine The pump draws hydraulic fluid from the oil tank 25 mounted on the sills 23 and 24 on the other side of the frame 2%. An operators hand lever 43 is mounted adjacent the motor 33 on the right side of the bed 22 of FIG. 1 and is connected to effect a splitting stroke of the ram tube 34 by actuating a hydraulic control mechanism indicated generally at 4:4. The mechanism 44 operates in response to the hand lever 43 to block the free return to tank of oil from the pump 4% thus to cause this oil to enter the motor 33, and to terminate this diversion upon the completion of the stroke.
Referring to the details of the splitting apparatus in FIGS. 35, the frame 2% includes a pair of angle beams 43 and as welded together to form a substantially rectangular box section, combining strength and torsional rigidity with light weight. A longitudinally extending steel plate is welded on upper surfaces of the beams 48 and 49 and thereby forms that which has previously been designated as the bed of the machine. The plate 5% is wider than the combined widths of the beams 48 and 49, and is arranged to overhang the beams by an equal amount on each side.
The splitting wedge assembly 35 is mounted on the plate 5%} at the end of the frame 2% adjacent the hitch assembly 32 and includes a pair of side plates 52 and 53 arranged in a V on opposite sides of a trapezoidal center plate 54. The wedge assembly 35 also includes a tough splitting axe 55 for efiecting the initial severance of the end of a log forced thereagainst by operation of the ram tube 34. The axe 55 is supported by the plates 52 and 53 in alignment on the plate 59 against the adjacent ends of the side plates 52 and 53 by bolt block 56. A key 56' integrally projecting from the axe 55 extends between the plates 52 and 53 and bolts 5'7 extend through the block 56 into the axe S5 for firmly but exchangeably securing the axe in the aligned splitting position shown. The assembly 35' further includes a wedge plate 6t? of relatively wide divergence mounted on top of the plates 52 and 53 in forwardly spaced relation to the axe 55 for the purpose of spreading the halves of the splitting log, thereby breaking fibers above the reach of the axe as the log progresses past the wedge assembly 35. The wedge plate 60 is held on the center plate 54 by bolts 51, and the side plates 52 and 53, which are fixed to the bed plate Ell. Additional support for the plate 60 is provided by a pair of braces d2 extending from the plate dd rearwardly to the lower surface of the plate 6%.
The motor 36 is mounted on the frame 20 and bed plate dd in part by means of a pair of cylinder head bearers 6d and 55. The bearers have lower ends welded at the open end of the frame 20 remote from the hitch assembly 32 and extend upward to terminate in a pair of cylinder head attaching lugs 66 and 67. A cylinder head 76 is secured to the lugs ed and 67 by bolts 71 and forms a closure for one end of the outer cylindrical casing of the motor 33 which will be designated hereafter as the outer cylinder '72. The other end of the cylinder 2 is open providing for limited transverse movement of the ram tube 34 without binding or strain on the motor 33. The head 7% is received within the rearward end of the cylinder 72 and in sealing relation therewith by means of an O-ring '73 between the cylinder 72 and the head '70.
The outer cylinder '72 rests upon three partly circular plates 74' mounted in upstanding relation on the plate 5d. A stop 75 is welded to the outside lower surface of the cylinder '72 Where it will just drop behind the rearmost saddle plate 7 1 when the rear end of the cylinder 72 contacts head bearer s4 and 65 thus preventing motion in either axial direction. The outer cylinder 72 is held down by two retainer straps 78 each having one end a-djustably fixed to a trunnion pin 79 carried within the saddle and the other end anchored to the frame 2%.
The hydraulic motor 33 includes means defining a first or inner hydraulic motor for effecting relatively high speed ram movement at moderate force and a second or outer hydraulic motor for effecting slow speed at greatly increased force. This is provided by means of an annular piston arrangement within the motor 33 and an inner open ended cylinder tube 80 having an end wall welded to an adaptor 82. The adaptor 82 is, in turn, buttressed against and sealed to and brought through a central hole in the head '75), the adaptor 32 being hollow to provide a connection for the application of hydraulic fluid from the hydraulic pump it) to the interior of the inner cylinder tube 30. A hydraulic piston 85 comprising a generally annularly shaped plate rides in sealing relation between the inner cylinder tube 80 and outer cylinder '72 upon inner and outer O-rings 86 and 87. The rings 86 and $7 lie in the same approximate plane on the piston 35 and are relatively unaffected by limited angular movement of the ram tube due to the strain of high forces. The inner end of the ram tube 354 is joined fluid tight to and supported by the piston 35 and has its outer end sealed by a ram tube closure plug 99 shown in broken outline form in FIG. 3. The inner cylinder tube 80 is opened into the interior of the ram tube 34. The arrangement of the open ended cylinders '72 and 80 with the sealing rings carried in substantially the same plane on the piston 85 provides for the absorption of lateral deflections without binding or wear.
The arrangement of the piston 35 and the inner cylinder tube St} and outer cylinder 72 provides first or inner and second or outer effective piston operating areas, the first area being the external cross-sectional area of the inner tube 86 and the second area being the difference between the inside cross section areas of the cylinder 72 and the inner tube 89. Hydraulic fluid may be applied to the inner area only by blocking free return to tank of pumped fluid by means of the control mechanism M. This fluid enters through the adaptor 82 and the inner tube 8 for action against the closure plug 9,9 of the rain for causing the extension of theram tube 34 along the plate 5%}. Pressure may also be applied to the outer piston area for the purpose described hereinafter through a connector 95 threaded into the cylinder head 70 and opened behind the piston 35.
The forward or advancing end of the ram tube 34 is guided throughout the entire length of the stroke by a ram guide unit indicated generally at 109 which includes a guide plate 191 securely welded to a base plate 102. The base plate 3.62 slides freely along the upper surface of the plate 5t; under the restraint of two guide shoes 5.63 bolted thereto, each having a longitudinal step notch 164 for-med therein to travel the extending portion of the plate 5h. The ram tube 34 passes through the guide plate ltil with free clearance to permit the relative flexiii-g under unbalanced stresses which occur during the splitting process. During extension of the ram tube 34, the plate Hi2 sweeps the log splitting bed clear of fallen particles of objectionable size.
A platen unit indicated generally at 135 consists of a pressure plate 166 secured by welding to a socket tube 107. The platen unit 105 is keyed to the guide unit 100 by means of a pin and supporting block assembly 1138 fixed in depending relation from the socket tube 107 and received in a free clearance hole formed in the base plate 162 of the unit Tilt). The socket tube 197 is telescoped with a free slip fit over the extended end of the ram tube 3 with the end of the ram tube in abutment against the inside surface of the pressure plate 106. The force of the ram tube 34 is thus directed against the plate 1%, and the platen unit 1% is thus guided by the guide unit 1% along the plate to drive a log on the bed of the splitter against the wedge assembly 35. A plurality of points 11% arearranged on the face of the pressure plate 1% for engaging the end of a log on the bed to prevent the slipping of the log.
Means for retracting the ram tube 34 includes a plurality of retraction springs 115 received totally within the rectangular box section formed by the frame 20. Each of the springs 115 has an outer end loop 115 secured over spring retaining cross pins 117 extending through the end of the frame 21 adjacent the hitch assembly 32. The inner ends of the springs 115 have inner end loops 118 secured through openings in a whifiletree 1120. The whifiletree 112i), is in turn, attached to one end of a ram return cable 122. As is best shown in FIG. 5, a ram return pulley 123 is mounted for rotation on a pin 124 extended between the sections 48 and t? of the frame 26. The top of the pulley 12.3 extends above the plate 5 3 through a notch 12's" cut into the end of the plate. The ram return cable 122 extends from the whiflletree 12% over the top of the pulley 123 and terminates in an opposite end loop 126 fastened to the platen unit 105 at the pin 1655. The springs 1-15, cable 122, and pulley 123 are thus protected by the frame 26 from exposure and damage.
In operation, the ram tube 34 carries the cable 122 out along the upper surface of the plate 50 causing theextension of the springs 115 within the frame 29. At the end of the splitting stroke the hydraulic control mechanism 4d ope-rates to relieve the fluid pressure within the motor 33, and the ram tube 34 is retracted by the cable 122 under th influence of the springs 115. The return of the ram tube is cushioned by the hydraulic fluid within the hydraulic motor.
The connecting arrangement of many of the individual components of the hydraulic control mechanism 44 on the frame 29 is shown in FIGS. 6 and 7. The primary operating control of the splitter is effected by the operation of the hand lever 43 to initiate a splitting stroke of the ram tube 34. The lever 43 is pivotally mounted by a pivot bolt 129 to a mounting plate 130 fixed to the side of the frame 29. A generally tubular valve operating lever 131 is pivotally connected to the portion of the hand lever 43 extending below the belt 129 and extends rearwardly alon the side of the frame to operate a specially modified balanced spool in-out valve 132 through a lost motion connection indicated generally at 133. The valve 132 comprises the primary control of the application of hydraulic fluid pressure to the inner cylinder 8t and may be constructed according to the teachings of the copending application of Brukner S.N. 760,702, filed September 12, 1958, now Patent No. 3,003,- 399. The valve 132 includes a valve body 134 within which is formed an inlet port 135 and a. pair of selectable outlet ports 136 and 137'. The valve body 134 is secured to the side of the frame 20 by bolts 138. The valveinlet port 135 is connected to the pump it} outlet through a tube 139 which is broken away in FIG. 6 for clarity of illustration, but which is shown in plan in FIG. 7. The outlet port 136 is connected to dump fluid from the inlet port 135 into the tank 25 through an elbow 149 and a short section of tubing left when the valve 132 is in its normal at rest position shown.
The hydraulic connections and the general arrangement of the internal details of the valve may be most readily understood by reference to the hydraulic connection diagram of FIG. 10 where the valve body 134 is shown as including a bore 142 into which. the ports 1315, 1'36 and 137 are opened. A shiftable spool 143 in the bore is formed with a reduced center section and may be operated between two selectable positions to establish communication between the inlet port 135 and either one of the outlet ports 136 or 137. A pair of snap rings 144 are secured in the portions of the spool 143 extending beyond the body 134 to define the limits of axial spool movement.
Spool valves of the general arrangement shown and described thus far are of generally inexpensive and reliable construction. A precision lapped fit between the spool and the body is not required since O-rings 145 are formed in suitable 0-ring grooves 146 on the spool 143 to prevent leakage. However such valves are generally unsuited for use as operating valves of hydraulic fluid under high pressure since the leakage past the spool at the high pressure outlet causes distortion of the adjacent (wing, and very effectively freezes the valves so that the spool cannot be moved with ordinary force or effort.
However, the spool valve 132 has been specially modified for use in this application, and the hydraulic circuit specially arranged so that the O-ring groove adjacent the one outlet port subjected to high pressure is at all times vented by being connected to the tank 25. A bleed pas sageway 1 58 is formed within the spool 143 and has one end opened at the O-ring groove 146 adjacent the pressure port 137, and the other end opened at the outlet port 136, when the valve spool 1 .43 is in the moved position for blocking the discharge of the pump into the tank 25. The passageway 1 h bleeds oil the fluid which leaks past the spool 143 to the groove 146 and elfectively prevents the distortion of the O-ring in the groove. Therefore, the passageway 148 assures that the spool is always freely movable into either limit position.
The spool 143 includes a threaded operating extension 150 for engagement with a plate 151 Welded to the end of the operating lever 131. The plate 151 is slipped over the end of the extension 159 between a pair of adjustable self-locking nuts 152 providing for lost motion therebe: tween and comprising the lost motion connection 133. Throttle control means for the engine 38 includes a Bowden wire actuator 153 attached for movement with the plate 151 of the lever 131 and includes a suitable connection to overpower the governor causing the engine to idle in the at rest position of the valve 132, and per? mitting the application of full governed engine speed to the pump 4-!) upon the movement of the spool 143 by the hand lever 43.
The connection 133 operates in conjunction with an overcenter mechanism identified generally at'155 shown in the at rest position in FIG. 6 and shown in the split-.
ting stroke position in FIGS. 9 and 1G. The mechanism 115 assures that the spool 143 of the valve 132 is in either one of the two limit positions de ending upon the position of the hand lever 43. The mechanism 155 includes a bellcrank d, pivoted on a bearing 157 and connected for rotation upon the movement of the handle 43 by a connecting link 15%. A curved spring hook 159 has one end connected for movement with the bellcrank 156, its mid-section being shaped to stop rotation by striking the bearing 157' and another end formed into a spring retaining hook portion 159 connected to a tension spring 169. The spring 16d normally holds the hand lever 43 through the mechanism 155 in the full line position shown in HG. 6 corresponding to the at rest position of the machine. When the lever 43 is moved forward, the lost motion 133 is traversed and the spool 143 of the valve 132 is shifted by the lever 131 to cause the initiation of a splitting stroke. At the same time, the mechanism 155 is cocked overcenter as shown in FIG. 9 and locks the potential energy stored in spring 16% for the subsequent positive return of the spool 143 of the valve 132 to its normal position when the hand lever 43 is moved toward its rearward position just enough to release the mechanism 155 overcenter thus releasing energy stored in the spring lil.
The limit of outward extended movement of the ram tube 34 along the bed plate is defined by the engagement of one of the ram guide shoes 1% With a slidable stop link 165. The stop link 165 has an inner end pivotally connected at the lever 4-3 and is, in etlect, an extension of the connecting link 131. An end portion 166 of the link 1165 is arranged to slide within a guide block 1d? formed on the side of the frame 26 and projects upwardly for engagement with the shoe 1% to release the over-center mechanism 15%. The forward movement of the shoe 103 against the stop link 165 causes the tripping of the mechanism 155 in the manner described to return the spool 143 to its initial position shown. This provides for the dumping of the fluid from both the inner tube 80 and from the pump 4% into the tank 25 through the valve outlet port 136 and the connector 141. The stop link 165 and the connecting link 131 form control means for the valve 132 responsive to a predetermined maximum extended position of the tube 34 to move the spool 14-3 to its initial at rest position. When slight motion of the link 165 trips the mechanism 155, the released energy of spring 16% rotates the bellcrank 156 with increasing velocity until the lost motion 133 has been traversed when the valve spool 143 joins the moving train subject to the gathered momentum and the then increased leverage of the spring 16%. Thus a small spring force is able to overcome the starting friction so common to precision fitting valves.
An auto-shift valve 180 of identical construction to the in-out valve 132 is mounted in inverted superimposed relation over the valve 132 with one port 181 being connected to the outlet port 137 of the valve 132 by a connector 182. A second port 133 is arranged to draw hydraulic fluid from the bottom of the tank 25 through a tank draw tube 185 and likewise to return the same on the return stroke. The valve 13% includes a mid port 183 connected to supply hydraulic fluid to the piston 85 through the connector 95 selectively from either of the ports 131 or 183 according to the position of the spool 18%, and in the normal at rest position shown, provides for the continuous filling of the space behind the piston 85 from the tank 25 by suction during the extension of the ram tube 34.
An auto-shift assembly 1% comprises a pressure re sponsive actuator for continuously measuring the resistance of the wood to splitting by sensing the hydraulic pressure on the system. The assembly 1% is housed in a cylinder case 191 which is welded onto a support frame 392 and held in a position to operate the valve 139 by a mounting plate 193 fastened to the valve 1% by bolts 194. The auto-shift assembly 1% is connected to operate the valve 189 through an overcenter spring mechanism indica ed generally at 195 (FIG. 7). The assembly 19% the mechanism 195, and the valve 1%, together comprise a pressure sensitive difierential snap action auto-shift device for causing the hydraulic pressure from the pump 46 to be applied to the entire available piston area of the motor 33 when required by increased resistance of the log to splitting.
The assembly 1% includes an end cap 1% threaded upon the cylinder case 1941. The cap 198 is drilled to freely accept and buttress the reduced end of a relatively fixed elongated piston (FIG. 14) in concentric relation to the case 1%. The piston 2% is extended through the cap 193 for threaded engagement with a pipe fitting on its exposed end completing its longitudinal fixity. A central fluid passageway 283 through the piston 2% forms an inlet for the hydraulic operating fluid from the fitting 2%. A movable cylinder 2% is fitted for relative axial movement over the piston 26% and for extended movement through a bore in the head 2% fixed in the end of the case 1 91 upon the application of hydraulic pressure to the passageway 2&3. A compression spring 287 is interposed within the case 191 and arranged to resist the extended movement of the cylinder 2%. One end of the spring 267 is in abutment with the head 2% and a snap ring received in the case 191 adjacent the open end thereof, and the other end of the spring 297 is carried on the inner end 01' the cylinder 2G5 by an annular spring 216) and a snap ring 211. The extended end of the cylinder 2% is closed by a plug 212 held in position by a pin 2135 providing for the retention of hydraulic fluid within the cylinder 205.
A shift mechanism operating bolt 215 is held in extending relation for movement with the end of the cylinder 2% and includes a bolt head 2.16 received within an opening formed between the outer end of the cylinder 2555 and a bolt retaining cap 217 fixed over the end of the cylinder 2%. The cap 217 provides for limited angu lar movement of the belt 2115 upon the extension of the cylinder 2&5 to provide the means by which the bolt follows the movement of the mechanism 195. The end of the bolt 215 is arranged for reciprocal movement within a trunnion 219' of an overcenter trip lever 2243. The lever 22% is pivotally mounted in needle hearings on a tab 221 formed on the frame 191 and includes an arm 224 with a depending pin 22 5 for engagement within a slot 228 formed in the end of a shift link 22%. The shift link 229 is pivotally pinned within a forked slot formed in the end of the spool 189 for effecting movement of the spool. The lever 22% further includes an extending spring arm 23%) to which is attached a tension spring 231. A pair of adjustable self-locking nuts 234 (FIG. 14) are threaded on the end of the belt 215 on either side of the trunnion 219 for defining the extent and location of free movement of the cylinder 2&5 before effecting movement of the trip lever 220, in either direction.
it will be recognized that upon the occurrence of a substantially increased log resistance the proportionately increased fluid pressure will extend bolt 215 (FIG. 7) suficiently to cause spring 239 to pass over the pivotal axis of trip lever 22% and expend its stored energy against the right-hand end of slot 228 in link 229 thus shifting the stem of valve 181% and communicating pumped pressure and volume with the total area of piston 35. The fluid pressure at the pump 4i) will then decrease due to the increased displacement area. This decrease in pressure allows the spring 2457 to retract the bolt 215 correspondingly and the lost motion provided for between the nuts 234- on the bolt 215' delays the return overcenter of the mechanism 1% and the re-shift to the inner cylinder operation until the log resistance has lowered within the capacity of the smaller area. The lost motion of the slot 2223 in the shift link 2329 allows the mechanism 195, when overcentered, to gain momentum and leverage be- 9 fore called upon to break the starting friction of the valve liiil. In addition, a damper valve 235, shown diagrammatically in FIG. 10, is provided in the pressure sensing line into the piston Zilil, for the adjustably restricted discharge of fluid from the assembly 1% for stabilizing the auto-shift assembly against a premature return to high speed operation by allowing the pump time to compress any air bubbles which may reside in the unpressu red larger area.
An understanding of the overall operation of the component parts of the machine as heretofore described may be had by reference to FIG. 10. It is assumed that the engine is operating and driving the pump 40 to draw hydraulic fluid from the tank 25. This hydraulic fluid is applied to the inlet port 135, of the in-out valve 132 and is applied at the same time to the interior of the ram tube 34 through a free passage in the body of a pressure relief valve 238 to the inlet coupling 82. The hand lever 43, and the parts associated therewith, are shown in the cocked position after having been forwardly moved by an operator for the purpose of splitting a log on bed 22. In this forwardly moved position; the end portion 156 of the stoplink 165 has been moved rearwardly for ultimate engagement with the shoe 193 in the fully extended position of the ram tube 34; The valve operating lever 131 has also been moved rearwardly as shown in FIG. 10, thereby shifting the spool 143 of the valve 132 to break the communication between the inlet 135 and the outlet 136 leading to the tank 25. Therefore, the full volume of the pump 40' is applied through the coupling 82 to the interior of the ram tube 34.
The extension of the ram tube 34 causes the extension of the retraction springs 11.5 by reason of the connection of the ram return cable 122 to the platen assembly IE5 at the pin 108. When the' ram tube has reached substantially the full extent of its travel, the shoe 193 engages the portion 166 (FIG. 6) to release the cocked overcenter mechanism 155 thereby shifting the spool 143 to permit the pump 41) and the inner cylinder tube 86 to dump into the tank through the valve 132. The ram tube is then retracted under the influence of the springs 155 as cushioned by the hydraulic fluid.
It will be seen that during this normal operation, the area behind the piston 85 has been continuously filled with fluid from the tank 25 through the coupling 95 by reason of the normal position of the valve 18d and suction created by the piston travel. As the ram tube is extended as described above, the piston 35 draws hydraulic fluid from the port 163 of the valve 1% through the port 183. Upon the return of the ram this accumulated fluid is also returned to the tank through the valve 180 by the same route.
Upon the occurrence of an unusually resistive log or stubborn knot, the auto-shift assembly 1%, which is connected through the damper valve 235 to the outlet side of the pump 4i causes the overcenter mechanism 195 to shift the spool 139 of the valve 180 into the lefthand position of FIG. 10. This breaks communication of the back of the piston 35 to the tank, but at the same time establishes communication to the pump 4 t} through the port 137 of the valve 132 and the port 131 of the valve 18%. Hydraulic pressure being spread over the considerably greater total area of the piston 85 and the inner tube ill the psi. falls by the ratio of the former to the sum total effective areas, and the total area is now available for causing the extension of the tube 34 as the pressure again increases to meet splitting resistance. After the passage of the wedge assembly 35 through the difiicult portion, the pressure at the pump will be reduced to such an extent that the spring 267 within the assembly 1% causes the retraction of the bolt 215, to the point where the reverse over-center action of the mechanism l95 occurs thereby shifting the valve 180 to its original position and removing the pump pressure from the piston 35 while reconnecting it to tank for furit) ther stroke filling. The extension of the ram tube 34 then continues in this mode until there occurs another highly resistive spot, or the stroke is terminated by the engagement of the shoe 103 with the portion 166 or the manual actuation of lever 41- either ofwhich trips the mechanism 155.
In manyinstances the wood to be split has previously been cut to a lengthconsistently shorter than the total effective stroke of the splitter. In order to shorten the splitting stroke and decrease the time lapse that would otherwise occur in the splitting of each shorter log, the splitter includes means for stopping the retraction of the platen at an adjustable rearward position along the bed plate 54 An elongated bar 24!) (FIGS. 2 and 11), forming an adjustable back stop, is positioned alongside the frame 29 just below the plate 59. The back stop bar 249 is movable by sliding along the side of the frame 2%) to engage one ofthe notches 241 formed therein Within a groove 242 in a back stop retaining plate 243 (FIG. 5). The forward end of the bar 24 4) is arranged to engage the left shoe T03 of the ram guide unit 1% upon the'retractionof the ram tube 34, and is held against the under surface of the plate 50 by a rolling glide M5 through which the bar 249 is passed. The glide 245 is attached to the front sill 23 by a tension spring 246 to draw down on the bar 240 rearwardly of the plate 2-13 and maintain the engagement of the front end of the bar with the plate 50.
The position of the back stop bar 249 may be changed at any time during the outward stroke of the tube 34 by lifting between the plate 243 and the glide 245 and sliding the bar 249 through the glide 245 along the frame. At the desired position, the bar 240 is released to permit the engagement of the plate 243 with one of the notches 241. A foot knob 24% is formed at the forward end of the bar 249 and may be depressed to lower the bar by pivotal movement about the plate 243 any time it is desired to permit the full retraction of the ram for a longer 10;; without the necessity of changing the notch position of the bar 240.
The loading of logs onto the bed 22 of the splitter is facilitated by lowering the frame 20 on the wheels 30, into a position nearer to the ground. In the lowered position, a minimum road clearance is maintained between the pan 29 and the ground so that the splitter can be wheeled or skidded into' position, as desired. The lowering and lifting mechanism for this purpose is shown in FIGS. 11-13 and includes the wheels 3i mounted on the levers 31, interconnected for movement with each other by the rockshaft 28, as previously described.
A lift arm 25%) is secured at the lower end to the rockshaft 28 for rotation therewith alongside of the frame 2% intermediate the levers 31. The frame 20 is held in the raised position corresponding to the full line drawing of the components in FIG. 11 by a retraction link 252. The link 252 has a lower section 253 pivotally mounted to the side of the frame 29 on a bearing pin 255 and an upper section 256 consisting of an elongated U-shaped bar with one long leg 258 and one short leg 25%. The short leg 25? is Welded to the inner extended surface of an L-shaped cut-out 260 on the lower section and the long leg 258 is Welded to the bottom side of the lower section 253 adjacent the cut-out 26b to form an enclosed track.
A bolt 262 is held in extending relation from the lift arm 25%) for engagement and movement within the track formed by the sections 253 and 256 of the retraction link 252 as described. The short leg 259 is terminated in a semi-circular bolt-receiving groove 2-53, and in the lowered position of the wheels shown, the bolt 25,2 rests within the groove 263. The relative position of these parts is maintained by a spring 264 attached between the arm 250 and the sill 23 and by the weight of the splitter as transferred through the lift arm 250 tending to rotate the arm into engagementwith the groove 253. The track servers ll of the link 7.52 operates with the lift arm 259 to define the raised and lowered positions of the splitter.
The frame 20 is positioned from the raised position shown to the lowered position, and from the lowered position back to the raised position under the control of a temporary interconnected lift cable 255 attached to the upper end of the arm 25%, as is perhaps best shown in FIG. 13. The free end of the lift cable 265 is formed with a loop 266 for temporary attachment over an inclined pin 26% fixed to the socket tube ill? of the platen unit M when it is desired to either raise or lower the splitter. In lowering the splitter, 21 lifter hook 279 is employed to release the engagement of the bolt 262 in the groove 263. The hook 27f is secured to the other end of the lift arm 25% by a tension spring 271.
The frame Ztl is lowered from the road position shown to the cutting position by attaching the hook 276 to a roll pin 272 fixed in extending relation from the section 253 adjacent the leg 25?. The splitter is caused to be operated through one cycle of operation by the movement of the hand lever 43 to extend the ram tube 34 along the plate 5%. The cable 265 is of such length that it pulls the lift arm 25% down at substantially the full stroke of the tube 34 to release the engagement of the bolt 262 with the groove 263. This condition is shown in MG. 12. The spring 271, acting on the pin 272 through the hook 279, overpowers the spring 264 to pull the retraction link 252 forward to hold the bolt 262 and groove 263 disengaged. Upon reaching the full extent of travel, the ram tube is returned under the influence of the retraction springs 115, and the lift arm 25% and the retraction link 252 assume the position as shown by the broken lines in FIG. 11 corresponding to the lowered position of the frame 20.
During the lowering of the frame, the lifter hook 27ft is swept off the pin 272 by the passing of the lift arm 250. Subsequently, when it is desired to raise the splitter to the road position, the ram tube 34 is again extended with the cable 265 attached to pull the lift arm 25% forward until the bolt 262 enters the l..-sl1aped cut-out 260. The retraction of the tube 34 causes the bolt 260 to again engage the groove 263 under the influence of the weight of the splitter and the spring 264. The spring 264 assure that the splitter does not accidentally lower during transit.
The raising and lowering mechanism previously described provides for convenience and ease in loading by rolling large diameter unsplit logs onto the bed 22 by decreasing the required lifting effort. A platform indicated generally at 28% in FIG. 15 may also be used to receive the portions of the log after splitting and to hold them off of the ground to reduce the amount of bending and lifting necessary to their removal. A is perhaps best seen in FIGS. 1 and 4, the hitch assembly 32, is secured to the frame by means of a pair of generally parallel L-shaped braces 2.31 fixed at opposite sides of the front of the frame 2% and terminating at the hitch in a slight upward inclination. The platform 23% is provided with ears 282, shown in broken outline on FIG. 15, for sliding engagement over the top flanges of the braces 2E1. A lJ-shaped cut-out is formed on the platform 2% to receive the end of the frame 2% when the platform 2% is slid onto the braces 281, and defines the assembled position or" the platform ass on the frame 29. In this position, a portion or the platform 289 lies on each side of the frame adjacent the wedge assembly 35 for receiving the wood as it falls from the bed 22 As a further convenience to the operation of the splitter, control means is provided for the fully automatic operation of the valve 7.32 so that a new splitting stroke is initiated immediately upon the completion of a preceding return stroke without the attention of the opera.- tor. This permits the operator to devote his attention to the loading of the bed and the removal of the split por- 12 tions of the logs. For this purpose, a repeater blocl 2%, shown in FIGS. 16 and 17, maybe attached to the stop link 165 for engagement with the shoe at any given point along the return stroke, for shifting the valve 132 and overcenter mechanism 355 to initiate a new splitting stroke of the ram tube 34.
The block 296' includes a groove 2% by which it is slipped over the link 165, and may be secured in any preselected position along the link M5 by a finger screw 2% threaded for frictional engagement with the link 165. The block 2% also carries an upwardly extending tongue 2% for engagement with the shoe ill?) upon the return of the platen unit 105. The tongue 2% is mounted on the block 2% for limited pivotal displacement upon a bolt 2% extending longitudinally thercthrough with a spring 2*)? positioned for compression upon the engagement of the shoe 103 against the tongue 295. The energy stored by the spring 2%? upon displacement of the tongue by the platen provides the necessary follow through movement to cock the overcenter mechanism 155. This prevents any possibility of the mechanism being only partially cocked or left on dead center.
If the operator desires more time than is afforded by the repeater block 2%, he may either move the block rearwardly on the link to increase the total stroke, or he may touch the hand lever 43 to uncock the mechanism 15%, thereby causing the returning shoe ill? to reengage the block 2% for initiating a new splitting stroke.
The operation of this invention is believed to be selfexplanatory from the preceding description. It is therefore seen that this invention provides a self-contained log splitter which is portable, compact and effective to split any type of log at the site of a fell.
While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.
What is claimed is:
l. A hydraulic log splitter comprising a generally rectangular hollow longitudinal bed arranged for receiving a log for splitting, an axe fixed adjacent one end of said bed with a splitting edge substantially in alignment therewith, a hydraulic motor having a first element fixed adjacent the end of said bed remote from said axe and a second element relatively movable with respect to said first element arranged for longitudinal extended movement along said bed toward said axe upon the application of hydraulic pressure thereto, a pressure plate arranged for longitudinal movement along said bed with said second element for moving a log on said bed against said axe upon the extended movement of said second element, an elastic member connected to resist the extension of said second member toward said axe including a spring received and protected within said bed, hydraulic motor control means including a position valve operable in a first position to apply hydraulic fluid under pressure to said motor to cause the extension of said second member toward said axe and in a second position to permit the return of said second member under the influence of said elastic member, and a control link having one end connected to operate said valve and another end engageable upon a predetermined maximum extended position of said plate to move said valve from said first position to said second position.
2. A hydraulic log splitter comprising a longitudinal bed arranged for receiving a log for splitting, a hydraulic pump, a throttle controlled engine connected to drive said pump, an axe having a cutting edge for passage lengthwise of said log to effect splitting thereof, means on said bed for eifecting relative movement of said axe and said log including a hydraulic motor having a first element fixed to said bed and a second element relatively movable with respect to said first element arranged for longitudinal extended movement against said log upon the application of hydraulic pressure to 'said motor from said pump, a spring having one end fixed relative to said bed and another end connected to resist the extension of said second member, hydraulic motor control means including a valve operable in a first position to applyhydraulic fluid under pressure from said pump to said motor to cause the extension of said second member and in a second position to provide for the return of said second member under the influence of said spring, valve control means responsive upon a predetermined maximum extended position of said second member to move said valve from said first position to said second position, and throttle control means connected for movement with said valve control means for throttling said engine in response to said maximum extended posi tion.
3. A hydraulic log splitter comprising a longitudinal bed arranged for receiving a log for splitting, an axe having a cutting edge for passage lengthwise of said log to effect splitting thereof, means on said bed for efiecting relative movement of said axe and said log including a hydraulic motor having a cylinder fixed to said bed and a ram arranged for longitudinal extended movement toward said log upon the application of hydraulic pressure thereof, hydraulic motor control means including an operators handle, a fluid control valve connected for operation by said handle between a first position to apply hydraulic fluid to said motor to cause said extended movement of said ram and a second position to provide for the removal of said fluid, an overcenter spring cocking mechanism connected for movement by said handle into a cocked position corresponding to said first valve position and into a released position corresponding to said second valve position, an operator having a direct connection to said handle and actuated by said ram upon a predetermined maximum extended position of said ram to release said cocking mechanism overcenter resulting in the return of said valve from said first position to said second position, and ram return means operable to eitect the retraction of said ram upon said return of said valve to said second position.
4. A hydraulic log splitter comprising a longitudinal bed arranged for receiving a log for splitting, an axe having a cutting edge for passage lengthwise of said log to effect splitting thereof, means on said bed for effecting relative movement of said axe and said log including a hydraulic motor having a cylinder fixed to said bed and a ram arranged for longitudinal extended movement along said bed upon the application of hydraulic pressure thereto, a spring having one end fixed relative to said bed and another end connected to resist the extension of said ram, hydraulic motor control means including a valve operable in a first position to apply hydraulic fluid under pressure to said motor to cause the extension of said ram and in a second position to provide for the return of said ram under the influence of said spring, and an adjustable back stop positionable to shorten the effective return stroke of said ram to reduce the time delay in splitting consecutively short logs.
5. A hydraulic log splitter comprising means for receiving a log in position for splitting, an axe having a cutting edge for passage lengthwise of said log to effect splitting thereof, means for effecting relative movement of said axe and said log including a first hydraulic motor for developing low force causing such movement at a high rate and a second hydraulic motor in force assisting relation to said first motor for developing substantially higher total force to overcome increase of resistance by said log to the passage of said axe, means for connecting said first motor to a source of operating pressure, a pressure responsive actuator connected to detect the pressure at said first motor and movable according to increased and decreased resistance of said wood to passage of said axe therethrough, an overcenter trip mechanism having a first lost motion connection with said actuator and a sec- (and lost motion connection, and a two-position valve controlled by said mechanism through said second lost motion connection, said valve connected to apply hydraulic pressure to said second motor to effect increased force upon the occurrence of said increased resistance and operable through the return movement of said mechanisin by said actuation to remove said pressure from said second motor upon the resumption of normal splitting resistance.
6. A hydraulic log splitter comprising a bed arranged for receiving a log for splitting, an axe having a cutting edge for passage lengthwise of said log to effect splitting thereof, a hydraulic motor for effecting relative movement of said axe to said leg including a cylinder fixed to said bed and a ram arranged for guided movement along said bed, said motor including means defining a first piston area for effecting extended movement of said ram on said bed upon the application of hydraulic pressure thereto and a second piston area isolated from and in force assisting relation to said first piston area, first controllable valve means for applying and removing hydraulic pressure to said first piston area for effecting longitudinal movement of said ram to effect relative movement of said log and axe, second controllable valve means connected to apply and remove hydraulic pressure to said second area to efiect increased displacement force of said ram, a pressure responsive actuator responsive to the hydraulic pressure at said first area, a lost motion coupling having a mechanical overcenter movement connecting said actuator with said second valve means to control said second valve means upon a predetermined increase in said pressure for applying pressure to said second area and upon a decrease in hydraulic pressure to remove said pressure from said second area.
7. A hydraulic log splitter comprising a bed arranged for receiving a log for splitting, an axe having a cutting edge for passage lengthwise of said log to efiect splitting thereof, a hydraulic fluid supply tank, a pump connected to draw fluid from said tank, a hydraulic motor for effecting relative movement of said axe to said log including a cylinder and a piston arranged for longitudinal movement toward said log, said piston including means defining a first piston area connected to receive hydraulic fluid directly from said pump for effecting longitudinal extended movement of said piston on said bed and a second piston area isolated from and in force assisting relation to said first piston area, a first balanced spool valve having an inlet connected to receive hydraulic fluid from said pump and a first selectable outlet connected to dump into said tank from said inlet and a second selectable outlet, at second balanced spool valve similar to said first valve having one of a pair of selectable ports connected to said second outlet of said first valve and the other of said pair connected to draw fluid from said tank and having a center port connected to said second piston area to supply hydraulic fluid to said second piston area from either said tanl: or said first spool valve depending upon the position of the spool in said second valve, means operably connected to said first valve to cause said valve to break communication between said first valve inlet and said tank for applying hydraulic pressure to said first piston area, and pressure sensing means responsive to a predetermined increase in pressure at said first area to cause said second valve to transfer communication of, said second area from said tank to hydraulic fluid under pressure from said first valve and further responsive to a predetermined decrease in pressure to return said second valve to its original position.
8. A portable log splitting machine comprising a substantially horizontally disposed log splitting bed, relatively movable log splitting apparatus mounted on said bed and operable through a splitting cycle for extension and return along said bed, fastening means fixed to said bed adjacent one end thereof for connecting said machine to a vehicle, a transverse rockshatt rot-stably, fixed to in said bed remote from said fastening means, levers fixed to said rockshait at either side of said bed for rotational movement th said rocxshaft, a pair of road Wheels one each rotatably mounted on each of said levers, and detachable means temporarily connecting said apparatus to said rocltshafit to rotate said roclrshsft in a cycle of ope ation for selectively raising said bed in relation to said wheels into a road position and for lowering said bed into a cutting position maintaining running clearance between said bed and the ground.
9. A portable log splitting machine comprising a substantially horizontally disposed log splitting bcd, relatively movable log splitting apparatus including a cylinder mounted on said bed having a piston driven ram arranged for telescoping movement with respect to said cylinder and extended movement along said bed, fastening means fixed to said bed adjacent one end thereof for connecting said machine to a vehicle, a transverse rockshaft r tatably fixed to said bed remote from said fastening means, levers fixed to said roclrshaft at either side of said bed for rotational movement with said rockshaft, a pair of road Wheels one each rotatably mounted on each of said levers, an arm connected to said shaft and extending adjacent said bed, a temporary manually connectable and removable link for connecting said ram to said arm for lowering said bed in relation to said wheels, and means providing limits of rotation of said arm defining the raised and lower d positions of said bed.
10. A raising lowering portable log splitting machine, comprsing a longitudinally extending splitting bed, a cylinder mounted on said bed adjacent one end thereof having a ram arranged for extending and retracting movement alons said bed in a cycle or"; operation, a transverse rock shaft rotatably mounted on said bed, a pair of crank evers one fixed to said rock shaft at each side of said bed, a pair of road wheels one mounted on each of said levers for rolling contact with the ground providing for mobility of said splitting machine, an arm connected to said shaft and extending adiacent said bed, a link living one end pivotally mounted to said machine and having another end forming a sliding connection with said arm ith means thereon defining the limits of rotation of said arm and rock shaft providing for movement between lowered and raised bed positions, and a V flexible connector having one end attached to said arm and another end adapted for temporary attachment to said ram to effect movement of said arm into either of said raised or lowered positions in a cycle of operation thereof.
ll. The log splitting machine of claim wherein said link includes means defining an enclosed track and said arm includes a pin movable in said track defining the limits of rotation thereof, said link further defining a notch for receiving said pin in said raised position ofi said bed.
12. A hydraulic log splitter, comprising a bed arranged for receiving a log for splitting, an axe fixed adjacent one end of said bed, a hydraulic motor cylinder having one closed end and one open end longitudinally posh tioned on said bed remote from said axe with said open end thereof facing said axe, a ram guide platen arranged for movement along said bed, a piston having an axial length less than the diameter of said cylinder and movably receive within said cylinder, a ram tube of a diameter less than said cylinder defining a clearance space therebetween and having an inner end supported on said piston and an outer end supported on said platen to transmit the force of said piston to said platen for movement along said bed, and means for applying hydraulic pressure to said cylinder at the closed end t ereof to effect splitting movement of said platen toward said axe.
13. A hydraulic log splitter, comprising a bed arranged for receiving a log for splitting, an axe fixed adjacent one end of said bed, a hydraulic cylinder having one open end and one closed end and longitudinally positioned on said bed remote from said axe with said open end thereof facing said axe, a ram guide platen arranged for movement along said bed, a piston having an axial length less than the diameter of said cylinder and movably received within said cylinder, a ram tube of a diameter less than said cylinder defining a clearance space therebetween and having an inner end supported on said piston and an outer end supported on said platen to transmit the force of said piston to said platen for movement along said bed, a hydraulic pump connected for direct application of hydraulic pressure to said cylinder at said closed end to effect splitting movement of said platen toward said axe, a tank, and a two-position control valve connected to said pump and to said tank and arranged in one position to dump the output from said pump into said tank and in another position to block communication with said tank to effect said splitting movement.
14. A hydraulic log splitter, comprising a bed arranged for receiving a log thereon for splitting, an axe fixed adjacent one end of said bed having a cutting edge for passage lengthwise of said log, a hydraulic motor for effecting relative movement of a log against said axe on said bed including an open ended outer cylinder having one closed end and being fixed to said bed at said closed end with the open end thereof facing said axe, an inner tube concentrically positioned Within said cylinder and fixed thereto at said closed end and having an open outer end, an annular piston having an axial length less than the diameter of said cylinder and slidably received between said inner tube and outer cylinder, a ram tube of a diameter less than said cylinder and greater than said inner tube defining a clearance space between said inner tube and ram tube and another clearance space between said ram tube and said cylinder having an outer closed end and an inner end received over said inner tube and connected to said piston, means guiding said closed outer end for extending movement along said bed, a source of hydraulic fluid under pressure, and valve means connected to apply fiuid pressure from said source selectively to the interior of said inner tube and to said outer cylinder.
15. The log splitter of claim 14 wherein said piston includes an outer O-ring forming a seal with said outer cylinder and an inner O-ring forming a seal with said inner tube, said G-rings lying generally in a plane transverse to the axis of said cylinder.
16. A hydraulic log splitter comprising a longitudinally extending ed for receiving a log for splitting thereon, a cutting axe fixed to one end of said bed having a cutting edge arranged for passage lengthwise through said log, splitting means for moving said log against said axe on said bed including a hydraulic motor having a cylinder fixed to said bed and a ram arranged for extended movement toward said log upon the application of hydraulic pressure to said cylinder, 2. two-position control valve connected to apply hydraulic fluid under pressure to said cylinder to cause said extended movement of said ram and further operable to remove said pressure, ram return means connected to said ram for effecting retracting movement thereof upon said removal of hydraulic pressure, a control link adjacent said bed connected to operate said valve movable by said ram at a predetermined maximum extended position of said ram to effect movement of said valve to a position removing pressure from said cylinder, and mechanical spring means connecting said ram with said link at a predetermined retracted position of said ram and operable with further retracting movement of said ram to effect reapplication of pressure by said valve for automatically initiating another cycle of operation.
17. A hydraulic log splitter comprising a longitudinal bed arranged for receiving a log for splitting and forming a ram guide, an axe fixed to said bed having a cutting edge for passage lengthwise of said log to effect splitting thereof, means on said bed for effecting relative movement of said axe and said log including a hydraulic motor having a cylinder fixed in relation to said bed and a ram tube arranged for longitudinal extended movement against said log upon the application of hydraulic pressure to said motor, a spring connected to resist the extension of said ram tube and to return said tube upon the removal of hydraulic pressure, a two-position hydraulic valve operable in a first position to apply hydraulic fluid under pressure to said motor to cause the extension of said ram tube and operable in a second position to provide for the return of said ram tube under the influence of said spring, an over-center trip mechanism having a lost motion connection to said valve and arranged to store energy in said first valve position, and a valve controller having a connection to said mechanism and arranged to effect release thereof upon a predetermined maximum extended position of said ram tube to return said valve through said lost motion connection to its second position providing for the automatic return of said ram tube under the influence of said spring.
18. A hydraulic log splitter comprising a bed for receiving a log thereon for splitting and an axe on said bed, a hydraulic motor for effecting movement of said log against said axe including an outer cylinder mounted on said bed, a cylinder head enclosing one end of said outer cylinder with the other end thereof being open and facing toward said axe, an inner open ended cylinder secured to said head in concentric relation to said outer cylinder with the open end thereof facing said axe, an annular piston slidably received between said inner and outer cylinders, a log driving ram tube proportioned to move between said inner and outer cylinders and having an inner end secured to said piston and a closed outer end, log driving means supporting said outer end for movement along said bed, a source of hydraulic fluid under pressure, a first selectable valve including a manually cockable overcenter trip mechanism operable to apply hydraulic fluid pressure when cocked from said source to said inner cylinder for efl'ecting relatively low force movement of said ram and operable when released to remove said hydraulic pressure, automatic pressure shifting means including a pressure actuator and a further overcenter trip mechanism, said actuator being connected to be responsive to the hydraulic pressure at said inner cylinder and operable upon a predetermined increase in said pressure to move said fur? ther mechanism overcenter and to return upon the re sumption of normal splitting resistance, and a second selectable valve connected to said source through said first valve and arranged to supply fluid to said motor at said outer cylinder and connected to said further mechanism to apply and remove hydraulic fluid under working pressure according to the resistance of the log to splitting.
19. In a hydraulic engine driven log splitter including a splitting bed arranged to receive a log thereon, and a throttle controlled engine driving a hydraulic pump connected to operate a hydraulic log splitting motor having an extensible member mounted for splitting movement on said bed, the improvement comprising a hydraulic motor control valve operable in a first position to apply hydraulic fluid under pressure from said pump to said motor to effect splitting movement of said member and operable in a second position to provide for return movement of said member, valve control means responsive to a predetermined extended position of said memher to move said valve from said first position to said second position, and throttle control means connected for movement with said valve control means for throttling said engine concurrently with the movement of said valve to said second position.
References Cited in the file of this patent UNITED STATES PATENTS 67,719 Burr Aug. 13, 1867 885,458 Eckenroth Apr. 21, 1908 951,937 Bryan Mar. 15, 1910 1,085,296 Perkins Jan. 27, 1914 1,851,622 Ernst Mar. 29, 1932 1,866,348 Ferris July 5, 1932 2,013,102 Ledbetter Sept. 3, 1935 2,054,296 Merrill Sept. 15, 1936 2,244,420 Dinzl June 3, 1941 2,348,445 Bayer May 9, 1944 2,577,462 Hackney Dec. 4, 1951 2,580,735 Dagenais Jan. 1, 1952 2,704,093 Brown Mar. 15, 1955 2,722,954 Carrier et al. Nov. 8, 1955 2,839,105 Gantenbine June 17, 1958 2,851,072 Gerjets et a1. Sept. 9, 1958 FOREIGN PATENTS 244,777 Switzerland June 2, 1947 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3,077,214 February l2 1963 Clayton; Jo Brukner It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.
Column 6, line 53 after "pump' insert 40 =--5 column 14 line 6, for "actuation' read actuator column 15, line 26 after "for" ins'pt rotating said rockshaft for raising and g' column 18, line 4L1 for "Carrier et a1," read Carver et alo Signed and sealed this 3rd day of September 1963,
ERNEST w. SWIDER DAVID LADD Attesting Officer Commissioner of Patents