US 2979837 A
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April 18, 1961 E. J. HUNTER 2,979,837
DITCH DIGGING MACHINE Filed Sept. 9, 1957 2 Sheets-Sheet l INVENTOR. "DW//v d HUA/735e mwm Trae/vir April 18, 1961 E. J. HUNTER 2,979,837
BITCH DIGGING MACHINE Filed sept. 9, 1957 2 sheets-sheet 2 a7 IW' l' llmuu- J4.
INVENToR. fZDW//V L/ /72//1/75@ YQQMEWM United States Patent C)Y DlTCH DIGGING MACHINE Edwin James Hunter, Moist OMatc Inc., P). Box 489, Riverside, Calif.
Filed Sept. 9, 1957, Ser. No. 682,740
9 Claims. (Cl. 37-94) This invention relates to ditch digging machines and included in the objects of this invention are:
First, to provide a ditch digging machine which is particularly designed to dig a narrow and relatively shallow ditch for the purpose of laying pipe used to connect the sprinklers of a sprinkler system and to form the ditch with a minimum of disturbance of the surface of the lawn or ground in which the pipe is to be layed, so that not only is the work of preparing the ditch minimized, but also the work of refilling the ditch and restoring the ground to its original condition is reduced to a minimum.
Second, to provide a ditch digging machine which utilizes a novel rotary cutting and digging assembly and novel dirt deecting means whereby the removed dirt is neatly windrowed along one side of the ditch.
Third, to provide in a ditch digging machine a cutting and digging assembly which is designed to rotate at relatively high speed and which incorporates a special clutch means and elongated spring arms arranged to slip and yield in the event excessive load occurs.
Fourth, to provide a ditch digging machine which may be readily and quickly converted into a boring machine for boring pipe receiving holes under sidewalks, driveways, or the like.
With the above and other objects in view as may appear hereinafter, reference is directed to the accompanying drawings in which:
Figure l is a partial elevational, partial sectional view of the ditch digging machine taken substantially along the line 1 1 of Figure 3 showing the cutting and digging assembly in its operating position.
Figure 2 is a side view thereof taken from the side opposite from Figure l and showing the cutting and digging assembly in its raised position.
Figure 3 is a transverse sectional view taken substantially through 3 3 of Figure l showing the manner in which the dirt removed from the ditch is windrowed alongside the ditch.
Figure 4 is an enlarged fragmentary view of the cutting and digging assembly.
l be any suitable conventional motor.
Figure 5 is a transverse sectional view through 5-5 p of Figure 4.
Figure 6 is a fragmentary plan view of the ditch digging machine with the motor removed and illustrating the manner in which the machine may be used to bore a pipe receiving hole under sidewalks, driveways, or the like.
The ditch digging machine is mounted on a pair of forward wheels 1 and a rear wheel 2. The forward wheels are carried by stub axles which terminate in mounting blocks 3 adapted to be bolted to the ends of a cross bar or front axle 4. The mounting blocks are so arranged that the front wheels may be moved between two right angular positions, that is, for the purposes of operating the machine as a ditch digger, the front wheels may be mounted with their axes parallel with the front axle, as shown in Figures 1, 2, and 3, or for'purposes j 2,979,831 Patented Apr. 18, 1961 lCe of operating the machine as a boring machine, with their axes at right angle thereto as shown in Figure 6.
The rear wheel 2 and the central portion of the axle 4 carry a pair of stirrups 5 and 6 which cap the lower ends of a pair of upright tubular posts 7. The stirrup 6 connected with the rear wheel 2 may be pivotally joined to its post so that the rear wheel may be moved into parallelism with the front wheels when the machine is used as a ditch digger as shown in Figures l, 2, and 3, or as a boring machine as shown in Figure 6.
The upper ends of the posts 7 are connected to a cross bar 8 one end of which is connected through au angle sleeve fitting 9 to a handle bar 10 terminating in a cross bar handle 11.
Slidably mounted on the posts 7 is a body structure 12 which includes a pair of sleeves 13 which receive the posts 7 and a connecting vertical plate or partition wall 14. 'I'he upper end of the plate is curved outwardly from the posts, then downwardly to form a dirt deflector hood 15 .as shown best in Figure 3. The ends of the plate 14 are joined to vertical end walls 16 which are enlarged at their upper ends to join and close the ends of the deflector hood 15.
On the side of the plate 14 opposite from the deflector hood 15 and at its lower margin is a platform 17, the forward and rearward extremities of which slope upward and are joined ot the sleeves 13. The body structure 12 formed by' the sleeves, end walls, plate and platform are welded together to form a rigid unitary structure which not only slides vertically on the posts 7, but also reinforce the frame formed by the posts 7 and cross bar 8.
Mounted on the platform 17 is a motor 18 which may A small internal combustion engine is shown; however, an electrical motor may be used, v
A lever arm 19 is pivotally mounted at the side of the cross bar 8 adjacent the rear post and extends forwardly therefrom. At its forward end the lever is pivotally connected to a lift bar 20, which is pivotally connected at.its lower end to a bracket 21 secured to the motor 18. Pivotal movement of the lever arm 19 raises and lowers the lift bar 20 and the body structure 12. Secured to the lever arm 19 is a hand lever 22 which, when the body structure is raised, as shown in Figure 2, extends alongside the handle bar 10 for convenient engagement. A retainer hook 23 is provided on the handle bar 10 to retain the bodyl structure in its upper position. An adjustable stop 24 is mounted on the lift bar 20 and is engageable with the cross bar 8 to limit the low position of the body structure 12 as shown in Figures l and 3.
'I'he motor 18 is provided with a drive shaft 25 which extends through the plate 14. Mounted on its extremity is journal disk 26 having a cylindrical bearing surface on which is fitted a bearing sleeve 27, preferably formed of nylon. Journaled on the bearing sleeve is a hub member 28. In the structure shown, the hub member is essentially square, but may have three or morev sides. Formed in one surface of the hub member adjacent each side is a channel 29 intersecting the periphery of the hub member at a corner thereof. Fitted in each channel is a digging arm or blade 30 which is anchored at its root end by a set screw 31. The blades 30 are preferably formed of spring steel and the side walls of the channels 29 diverge therefrom to permit spring movement of the blades 30 in the plane of rotation of the hub member.
The hub member receives a cover plate 32 which covers the channels 29. The journal disk is provided with a flange 33 which backs the hub member 28. Secured to the journal disk by a pair of stud bolts 34 is a clutch plate 35 which overlies the cover plate 32. Interposed between the flange 33 and hub member 28, and between the clutch Y 3 plate 35 and the cover plate 32 are friction or clutch disks 36. The stud bolts 34 are provided with Springs 37 which bear against the clutch plate 35 to provide clutch pressure on the disks 36 so that the hub member 28 and digging blades 30 are frictionally -driven by the motor 18.
The digging -blades 30 preferably taper toward their.
extremities, and Vtheir tip ortions 38 are bent slightly in the direction of rotation. The leading sides are covered with a hard facing material 39 such as tungsten carbide. The digging blades are disposed in a plane adjacent to the plate 14 and are housed within the end walls 16 and deflector hood 15. The digging blades 30 project below the body structure 12, but clear the ground when the body structure is elevated as shown in Figure 2.
Operation yof the ditch digging machine is as follows:
The motor is started with the body structure in its elevated position as shown in Figure 2. .After positioning the machine over the path of the intended ditch, the body structure is gradually lowered by raising the hand lever 22 until the stop 24 engages the cross bar 8. The stop 24 is preset to determine the depth of the ditch as shown in Figures l and 3. The machine is then rolled forward as the digging arms or blades 3i) rotate. The arms or blades 30 sling the dirt and sod upwardly against the deflector hood with suflicient force that the material is deflected 186 and to one side where it falls in a windrow B along one sideof the ditch A.
The digging arms or blades produce a ditch somewhat wider than the blade width; however, the ditch need not be appreciably wider than the pipe which it is to accommodate; that is, essentially, a slit trench. By reason of the fact that the digging blades are relatively long and slender, and are formed of spring steel, and by reason of the diverging walls of the channels 29 which tend to limit movement of the blades within their elastic limits, the blades yield readily to excessive transient loads such as are produced when small rocks, pebbles, or roots are encountered.
The hub member is preferably formed of lightweight rnetalto minimize inertia. This, together with the friction mounting of the hub member, permits the digging assembly to slip relative to the drive shaft if excessive .loads are encountered. Insevere conditions, the digging assembly may actually stall without damage. Should this occur, the body structure and digging assembly may be raised, or the machine backed to relieve'the condition.
In order to use the machine asa lboring machine, the wheels are turned at right angles tothe position shown in Figures l, 2, and 3; that is, to the position shown in Figure 6. The cross bar 8 is provided with a lateral stub shaft 40 to receive the fitting 9 ,and position the handle bar in parallelismwith the drive shaft of the motor 18. A cross bar 41 is then secured between the bolts 34.
l. A ditch digging machine, comprising: a frame in cluding vertical posts and a cross bar connecting the up Y deector hood at the upperend of said partition wall be- Mounted on the cross bar 41 is a universal joint 42 from which extends a tubular boring-shaft 43 which maybe tipped with a bit 44. Suitably Vjournalled and sealed on the boring shaft is sleeve 45 having va lateralinlet 46 for connection to a hose.
The machine is used as a boring machine by positioning the body structure in a raised position, then operating the motor 18 to rotate the boring shaft 43. The shaft is sudiciently exible and of such length that it bends or curves of its own weight until its drilling end tends to lie substatnially horizontally in the bottom of a slit ditch at level to bore Yunder a sidewalk, driveway, or the like. By circulating water through the shaft 43 and forcing the machine along the axis of the shaft, a pipe receiving hole may be bored under such sidewalk, driveway, or the like. The boring shaft 43 may, in fact, be a length of pipe and be left inv place on completion of the boring operation.
Although a particular construction combination and arrangement has been shown and described as exemplifying an embodiment of the invention, it is to be understood that-the invention is not limited to the embodiment shown,
but. -embracesthescope Vof theV appended. claims.,
tween said end walls, and a motor supporting platform at the side of said partition wall opposite from said deector hood; means for raising and lowering said body structure relative to said posts; a motor mounted on said platform and having a shaft .extending through Vsaid partition wall; a digging unit rotatably mounted onsaid shaft parallel to said partition wall within the boundaries of said deflector hood and end walls; said digging unit adapted to be lowered with said body structure for ground engagement to cut a slit trench therein, said digging unit tending to throw material against said deilector hood for deflection into a windrow alongside said slit trench.
2. A ditch Vdigging machine, comprising: a 'frame including vertical posts and a cross bar connecting the upper ends of said vertical posts; wheels supporting the lower ends of said posts; a body structure including sleeves slidable on said posts, a partition wall connecting said sleeves, end walls extendingV laterally of said sleeves, a deector hood at the upper end of said partition wall between said end walls, and a motor supporting platform at the side of said partition wall opposite from said deector hood; means for raising and lowering said body structure relative to said posts; a motor mounted on said platform and having a shaft extending through said partition wall; a digging unit rotatably mounted on said shaft parallel to said partition wall within the boundaries of said deector hood and end walls; said digging unit including a hub, a friction drive clutch connecting said hub with said motor shaft, spring arms extending from said hub, and digging tips on said spring arms; said digging unit adapted to bellowered with said body structure for ground engagement to cut a slit trench therein, said digging unit tending to throw material against said deflector hood for deection into a windrow .alongside said slit trench.
3. A combined slit trench digging and hole boring Vmar chine, comprising: a frame structure; wheel means; means for securing said wheel means to said frame structure to move said frame structure in a longitudinal or a lateral direction; a body structure vertically movable on said frame structure; a rotary slit trench digging unit carried by said bodystructure; means for feeding said body structure and digging unit vertically to cause said digging unit to cut a slit trench; a tubular drilling unit, and means for attaching said drilling unit tok said digging unit, said drilling unit being operable by said digging unit upon raising said bodystructure and disposing said wheel means for lateral movement of said frame structure.
4. A ditch digging machine, comprising: a wheeled frame structure including forward and rearward wheels; a body structure vertically movable on said frame structure between said' wheels and including a partition wall parallel to the.direction of travel of said wheeled frame structure terminating at its upper end in au inverted channel member forming a deflector hood also extending parallel to the direction of travel of said wheeled frame said partition wall for deection by said hood into a windrow deposit at one side of said digging unit.
5. A ditch digging machine. comprising: a wheeled frame structure; a motor having an axis disposed transversely to the direction of travel of said wheeled frame structure; a ditch digging unit driven by said motor and including radiating digging arms defining a common vertical plane parallel to the direction of travel of said wheeled frame structure; a partition wall interposed between said motor and digging unit in a vertical plane parallel to the direction of travel of said frame structure and contiguous to the plane of said digging arms; a deector hood continuing upwardly from said wall and curving upwardly and laterally therefrom over the plane of said digging arms, then downwardly and laterally whereby earth thrown upwardly by said digging arms is redirected downwardly in a plane laterally of said digging arms and on the opposite side thereof from said partition wall; and means for raising and lowering said digging unit for ground engagement of said digging arms thereby to cause earth to be thrown upwardly against said deector hood.
6. A ditch digging machine as set forth in claim 5, wherein: said ditch digging unit includes a hub having tangentially directed arm receiving channels, each channel including a root end, an extended end and continuous opposite walls diverging toward said extended end; said digging arms being fastened at the root end of said channels and being free to ex within the boundaries of said diverging walls said diverging walls being curved away from opposite sides of said digging arms to define safe limits of deection thereof.
7. A ditch digging machine, comprising: a motor having a horizontally directed drive shaft; a ditch digging unit mounted on said shaft, said unit including a hub plate having a plurality of tangentially disposed channels, each channel having a root end andan extending end, and including continuous side walls diverging toward said extended end in the planeY of said hub plate; digging arms secured at the root ends of said channels and projecting outwardly therefrom, said digging arms being substantially straight and defining a plane common to said hub plate and being free to ex therein within the boundaries of said diverging channel walls; and means for raising and lowering said ditch digging un'it for ground engagement by the extremities of said digging arms, said diverging side walls being curved away from opposite sides of said digging arms to define safe limits of deection thereof.
8. A ditch digging unit for a ditch digging machine, comprising: a journal member mounted for rotation and having a clutch face at one axial end; a clutch plate confronting said clutch face; spring means urging said clutch plate toward said clutch face; a hub member, a cover plate therefor, and clutch elements mounted on said journal member between said clutch face and said clutch plate, whereby said hub member tends to rotate with said journal member; said hub member having tangentially disposed slots covered by said cover plate, spring fingers disposed in said slots and extending tangentially therefrom, said spring fingers having a substantially straight unstressed condition;` and means for securing each spring finger in its slot; the side walls of each slot being continuous and diverging from each other and from the spring finger therebetween and defining safe limits of defiection of said spring finger in opposite directions from its unstressed condition.
9. Means for digging a slit trench, comprising: a 'rotatable shaft; a friction clutch mounted on said shaft and including a clutch plate structure disposed for rotation in the plane of the slit trench to be formed, said clutch plate structure adapted to slip and yield when subjected to loads above a predetermined value; said clutch defining a ring of tangentially disposed slots each having a root end and an extended end; and a tangentially disposed spring finger secured at the root end of each slot, each spring finger being substantially straight in its unstressed condition; each of said slots having continuous walls diverging from each other and from the corresponding spring finger to define continuously curving safe limits of deflections of said spring nger in opposite directions from its unstressed condition.
References Cited in the file of this patent UNITED STATES PATENTS 1,282,786 Entz Oct. 29, 1918 1,538,565 Loken May 19, 1925 1,858,360 Cruse May 17, 1932 2,020,524 Smthburn Nov. 12, 1935 2,051,443 Gravely Aug. 18, 1936 2,054,129 Kelsey Sept. 15, 1936 2,679,703 Borel June 1, 1954 FOREIGN PATENTS v 623,902 Great Britain May 25, 1949