Self-propelled lawn aeration machine

A hollow tine for a self-propelled lawn aeration machine is formed by a U-shaped metal plate having a stud projecting internally of the plate and welded thereto at one end. The U-shaped metal plate has an oblique cutting edge at the end remote from the stud, includes side edges parallel to each other to define a narrow slot extending from the cutting edge to the stud. The cutters where the oblique cutting edges meet the side edges of the U-shaped metal plate are pinched in to reduce the cross-section of the hollow tine formed thereby to facilitate the release of a plug cut from the turf during penetration of the tine into the turf. The handle assembly pivotably mounted to a lawn aeration machine platform at one end has a wheel rotatably mounted thereto, and the handle is rotated and adjustably locked in a first position in which the chassis end is raised to in turn raise a tine support and drive mechanism above the turf to prevent tine penetration of the turf, and a second locking position with the tine support and drive mechanism is lowered to effect penetration of a plurality of tines in sequence into the underlying turf and to effect plug removal therefrom after tine retraction.

FIELD OF THE INVENTION 
This invention relates to machines for perforating turf, removing plugs and 
insuring admittance of air, light and water to the roots thereof. 
Machines of this type conventionally employ a series of perforating spikes 
or tines, either solid or hollow, and a mechanism for periodically driving 
the tines into the turf to a predetermined distance and removing of same. 
In some case, the action of the tines entering the earth and being 
retracted therefrom functions to pull the machine across the lawn. 
Typically, a small internal combustion engine, such as that normally found 
on a power lawn mower, provides the power necessary to drive the tines 
into the ground and remove the same and effects self-propulsion of the 
machine. 
Such machines have been patented over the years. Representative patents are 
the following: 
______________________________________ 
U.S. Pat. No. 
Patentee Year Patented 
______________________________________ 
2,056,337 Archiblad 1936 
2,206,264 Rose 1940 
2,223,559 Fleming 1940 
2,229,497 Dontje 1941 
2,302,944 Helbig 1942 
2,347,748 Melling 1944 
2,638,831 Ferguson et al 
1953 
2,800,066 Cohrs et al 1957 
3,022,834 Ruka et al 1962 
3,136,274 Townsend 1964 
3,148,737 Lunsford 1964 
3,429,378 Mascaro 1969 
3,204,703 Hansen 1965 
3,743,025 Thatcher 1973 
3,802,513 Ploenges 1974 
3,834,464 Carlson et al 
1974 
3,878,899 Jones 1975 
3,889,761 Rogers 1975 
4,084,642 Killion 1978 
4,096,915 Groth 1978 
4,154,305 Prewett 1979 
4,236,582 Hastings 1980 
______________________________________ 
U.S. Pat. No. 3,022,834 to Ruka et al is representative of a rather light 
weight tubular metal frame type machine in the form of a pushcart mounting 
a small internal combustion engine which utilizes a V-belt drive for a 
main drive shaft extending transversely across the top of the frame. A 
sprocket and chain drive system facilitates rotation of paired forward and 
after crank wheels, each bearing a pin connected crank whose lower end 
terminates in a tine and whose lower end is guided by a pivotable link 
permitting the tines to enter and to be retracted from the ground in a 
sequential manner. 
U.S. Pat. No. 3,429,378 to Mascaro is directed to a somewhat more massive 
machine which employs an inverted U-shaped frame which mounts vertically 
upper and lower crank shafts similar to that of an automobile with the 
crank shafts being joined or connected by crank arms. The crank arms each 
mount, at their lower ends, a tine assembly including a plurality of 
hollow tines for punching and removing turf cores. 
U.S. Pat. No. 4,084,642 to Killion teaches a low slung tubular metal frame 
which mounts at an upper location a transverse shaft driven in rotation 
and bearing a plurality of eccentrics. The eccentrics are connected, via 
rods pivoted to the eccentric, blocks which, in turn, threadably carry 
projectable and retractable tines for perforating the turf. Tubes, 
surrounding the blocks, function as pivotable guides to guide the 
reciprocation of the tines driven by the eccentrics. 
U.S. Pat. No. 4,154,305 is directed to a perforating machine having a wheel 
supported main frame upon which mounts an internal combustion engine whose 
output via belt and pulley means drives upper and lower shafts which, in 
turn, constitute a bell crank mechanism for vertically lifting and 
dropping a rigid tine support platform, thereby causing the platform to 
move in a defined horizontal and vertical direction and to effect the 
penetration of the tines into the earth and removal of the same. 
The patents discussed in some detail are representative of the art. The 
machines such as those of U.S. Pat. Nos. 4,154,305 and 3,429,378 are quite 
massive and therefore costly, and while the timing of the multiple tines 
in U.S. Pat. No. 3,429,378 is carefully controlled, it is achieved through 
the utilization of massive and fairly complex multiple crank shafts. 
Attempts to create relatively lightweight but effective machines such as 
those of U.S. Pat. Nos. 3,022,834 and 4,084,642 permit a more simplified 
drive system, but the desired action of penetration of the tines into the 
ground, the effective drive of the mechanism as a result thereof across 
the surface of the turf, and penetration and retraction in a vertical 
straight line fashion to minimize turf deformation about the hole, is 
frustrated due to the drive system employed. Further, the machines 
discussed effect relative low velocity movement of the tines, minimizing 
the power application to the tines during the penetration and retraction 
process. 
It is, therefore, a primary object of the present invention to provide an 
improved self-propelled lawn aeration machine which is of simplified 
construction, utilizes a single chain driven wheel to effect rotation of a 
series or sets of upper and lower wheels connected by jack shafts which, 
in turn, bear the tines under conditions in which the timing of the tine 
penetration and retraction from the ground may be readily varied, and 
wherein the movement into and out of the ground perpendicular thereto is 
assured. 
SUMMARY OF THE INVENTION 
The invention is principally directed to a light weight, compact 
self-propelled lawn aeration machine which includes a generally horizontal 
chassis platform, an internal combustion engine mounted on the plateform, 
and at least one tine support and drive mechanism mounted to the platform 
and operatively coupled to the engine. The tine support and drive 
mechanism includes a plurality of tines for cyclic movement downwardly of 
the platform to effect penetration of the underlying turf for aeration 
thereof and retraction therefrom. The improvement resides in means for 
fixedly mounting upper and lower vertically spaced hollow cylindrical 
wheel mounting journals to the platform with their axes horizontal, a 
shaft rotatably mounted within each journal and protruding to each side 
thereof, a first wheel rigidly fixed to the end of each shaft and a second 
wheel removably mounted to the other end of the shaft such that upper and 
lower wheels are mounted to opposite sides of the wheel mounting journals. 
The wheels have a plurality of holes at uniformly circumferentially spaced 
positions at equal radial positions outwardly of the wheel axis. A hollow 
cylindrical jack shaft journal is provided for each of the wheels. Bolt 
and nut means rotatably mount a jack shaft journal at a given one of the 
holes of each wheel. A jack shaft is fixedly connected between and joins 
the jack shaft journals of each set of wheels. The jack shaft journals of 
one wheel set are bolt connected to holes within the set of wheels 
angularly offset, less than 180 degrees from the jack shaft journals 
mounted to holes of the other wheel set, such that the wheels are kept in 
time by the jack shafts and the timing and direction of rotation of the 
wheel sets are determined by the direction and degree of angular offset of 
the jack shafts. Tines are fixedly mounted to the jack shaft journals of 
the lower wheels of both sets and project downwardly and in line with the 
jack shafts adjoining the jack shaft journals of each wheel set. As such, 
the tines enter and leave the turf perpendicular to the ground. Only one 
tine enters the turf at a time, and machine propulsion is automatically 
effected as a result of driving of the tines into the turf and retraction 
therefrom. Further, the timing of penetration of the tines into the turf 
and retraction therefrom may be readily varied by selectively changing the 
angular position of the jack shaft journals of one wheel set relative to 
that of the other wheel set for the at least one mechanism. 
The lower wheel of one of the wheel sets for the at least one tine support 
and drive mechanism may comprise a sprocket wheel, and the machine further 
comprises drive means including a drive sprocket operatively coupled to 
the internal combustion engine and a chain linking the drive sprocket and 
the sprocket wheel. The at least one tine support and drive mechanism may 
comprise two mechanisms mounted laterally side by side on the platform. 
The internal combustion engine may be mounted to the end of the platform 
remote from the two tine support and drive mechainsms, and a pair of metal 
risers fixed to the platform and extending generally at right angles 
thereto, and generally vertically upward and parallel to each other, act 
to mount at least one of the wheel mounting journals. A main drive shaft 
extends horizontally across the risers, and means are provided for 
rotatably mounting the drive shaft to the risers for rotation about its 
axis. The internal combustion engine has a drive shaft parallel to the 
main drive shaft. V-pulleys are fixedly mounted to the internal combustion 
engine shaft and the main drive shaft, respectively, and means are 
provided for adjustably mounting an idler pulley on the platform. An 
endless belt is trained over the pulleys to effect drive from the internal 
combustion engine to the pulley mounted to the main drive shaft. A pair of 
drive sprockets are mounted to the main drive shaft in line with a lower 
wheel of each of the tine support and drive mechanisms with that lower 
wheel constituting a sprocket wheel. An endless chain engages drive 
sprockets and the lower sprocket wheel of each of the mechanisms. The 
sides of the drive sprockets and the sprocket wheels are such that the 
sprocket wheels rotate at high speed and function as highly effective 
flywheels to maximize the force tending to drive the tines into the turf 
and remove the same and to improve machine self-propulsion resulting from 
sequential tine penetration into the turf and retraction therefrom. The 
holes within each of the wheels may be circumferentially spaced at 90 
degrees to each other, 60 degrees to each other, 45 degrees to each other, 
or a combination of the same. 
Hollow tubular members may be fixedly connected to the jack shaft journals 
of the lower wheels of each wheel set, which hollow tubular members 
project radially therefrom in line with the axis of the jack shaft 
connecting the jack shaft journals of the upper and lower wheels of the 
set with the hollow tubes being threaded internally. The tines may each 
comprise a U-shaped metal plate welded at one end to a threaded stud 
projecting internally of the U-shaped plate with the threaded stud being 
threadably received by the internally threaded tube. A nut carried by the 
threaded stud and a lug washer on the threaded stud between the nut and 
the end of the threaded stud permits the tine to be shifted axially 
relative to the tube and fixed at the axially adjusted position. The 
U-shaped plate preferably terminates at its end remote from the threaded 
stud in an oblique cutting edge. Further, the corners where the oblique 
cutting edge meets the side edges of the U-shaped plate defining a narrow 
slot between those side edges are pinched in such that the effective 
cross-section of the hollow tine where it initially penetrates the turf is 
less than the cross-section of the hollow tine above the pinched in 
corners, facilitating the release of a plug created by penetration of the 
tine into the turf, with the slot within the U-shaped tine plate above the 
pinched in corners permitting a plug to be ejected from the tine during 
subsequent repenetration into the turf and the creation of a new plug. 
Preferably, the threaded stud internally of the U-shaped plate is 
obliquely beveled to cam the plug outwardly of the tine through the slot 
as the plug moves axially within the hollow tine in the direction of the 
threaded stud.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring initially to FIGS. 1 and 2, the self-propelled lawn aeration 
machine, indicated generally at 10, comprises a wheeled frame or chassis, 
indicated generally at 12, bearing the components of the machine. A pair 
of vertically offset angle bars 14, 16 are provided on each side of the 
machine which are welded together via plates 13. Crossbars 17, 22 are 
welded across the ends of angle bars 14, 16, respectively, at the front 
and rear of chassis 12. Generally vertical risers 18 are welded to angle 
bars 16 and are joined by a crossbar 62 at the tops of risers 18. Crossbar 
22 is of hollow rectangular cross-section. Crossbar 17 is welded across 
and joined at its end to angle bars 14 at the front of the machine chass 
12. Journals 24 to each side of the frame 24 receive the pintels 26a of 
forks 26 which, in turn, rotatably mount front wheels 28 via axles 29, the 
axles being mounted to the lower ends 26b of the forks 26. Angle bars 14 
define a front platform 15 upon which is mounted a small internal 
combustion engine 42. To the rear of the frame 12, on rear platform 19, a 
pair of bars 30 welded to rear platform 19 function to support by 
pivotable connecting pins 31, 33, a pair of depth adjustment lock bars 32, 
and depth adjustment rod 34, respectively. Pivoted to the depth adjustment 
lock bars 32 adjacent its end remote from pin 33, via pin 35, is a latch 
adjustment plate 36 which is apertured so as to receive the threaded 
projecting end 34a of the depth adjustment rod 34 and permitting by 
shifting of the latch adjustment plate 36 on rod 34 angular adjustment of 
the depth adjustment lock bars 32. Nuts 37 are threaded to threaded end 
34a of rod 34, to respective sides of latch adjustment plate 36, to 
maintain the depth adjustment lock bars 32 at a predetermined height above 
bars 30 and at a given angular position with respect to the lower pair of 
bars 30. Welded across the ends of depth adjustment lock bars 32 is a 
first pin locking plate 39 which terminates at its lower end in an 
angularly bent camming portion 39a. A transverse elongated slot or recess 
41 is formed within latch plate 39. Above slot 41, there is welded to the 
outside face of the locking plate 39, a rectangular block or stop 43 which 
acts, as best seen in FIG. 8a, as a stop for limiting pivoting of handle 
assembly frame member portions 122b beyond a position generally in line 
with the pair of depth adjustment lock bars 32. 
In similar fashion a second pin locking plate 45 is welded across the end 
of paired bars 30 which second or lower locking plate 45 terminates at its 
upper end in an oblique, forwardly bent camming portion 45a. Further, an 
elongated transverse slot 47, similar to that at 41, is formed within the 
lower locking plate 45. 
The two frame risers 18, on opposite sides of frame 12, and the crossbar 62 
welded thereto at the top provide a relatively rigid support structure for 
the mechanisms which both support and drive a plurality of turf plug tines 
108. Inclined struts or reinforcing plates 20 welded to angle bars 14 and 
risers 18 further strengthen the risers 18. To effect that drive, the 
internal combustion engine 42 has coupled to an output shaft 44, a 
relatively large diameter V-type drive pulley 46, by way of key 48. 
Mounted to and extending between the frame risers 18 is a main drive shaft 
58 which extends transversely across the machine, above frame rear 
platform 19. To the left side of the machine 10, shaft 58 carries a 
relatively small diameter V-pulley 56. An endless belt 50 is trained about 
V-pulleys 46, 56 and passes over an idler pulley 52. The idler pulley 52 
is vertically adjustably mounted on a support block 54 which rises 
upwardly from and is fixed to front platform 15. The support block 54 is 
provided with an elongated slot 57 through which projects adjustment bolt 
55 on which mounts the idler pulley 52. As such, the idler pulley 52 can 
be raised or lowered and fixed at a vertically adjusted position to 
provide the requisite tension to the drive belt 50. 
By reference particularly to FIG. 2, it is seen that the main drive shaft 
58, which is supported for rotation about its axis by trunions fixed to 
risers 18, has keyed by way of keys 63 a pair of sprockets 66 whose 
integral hubs 64 facilitate that mechanical connection to the drive shaft 
58. As such, the sprockets 66 form components of left and right multiple 
tine support and drive mechanisms 74, 76, respectively, to effect, 
automatically, high speed plug removal and self-drive of the machine 
across turf T, from which turf plugs are removed. 
Mechanisms 74 and 76 are mirror images of each other, and like elements 
bear like numerical designations. In that respect, to each side of the 
machine the angle bars 16 have fixedly mounted thereto, as by being 
welded, hollow cylindrical metal journals 68, within which are mounted 
shafts 72 via dual, opposed bearing halves 70, 71. It should be 
appreciated that each tine support and drive mechanism 74, 76, comprises 
four wheels. A primary or drive wheel 80, which constitutes a sprocket 
wheel, in that teeth are provided on its periphery, is connected via an 
endless chain 81 to a drive sprocket 66 fixed to the main drive shaft 58. 
In line with lower wheel 80 is a further wheel 100 constituting the upper 
wheel of a first wheel set involving wheels 80, 100. To the opposite side 
of journal 68, a second lower wheel 116 is provided for each mechanism 
which is in line with and is mechanically coupled to an upper wheel 112, 
to that side, and forming a second set of wheels therewith, similar to a 
set of wheels 80, 100 to the machine inside of journal 68. 
Sprocket wheel 80 is provided with an integral hub 78 which hub is keyed to 
shaft 72 via key 79. Integrally formed with shaft 72, to the outside of 
the frame 12, is the other lower wheel 116 of each assembly 74, 76. All 
four wheels 80, 100, 112 and 116 are of equal diameter. Further, the 
wheels are all supplied with a number of circumferentially spaced holes. 
In the illustrated embodiment, holes 101, are provided 90 degrees apart 
and 60 degrees apart, as seen best in FIG. 3 to facilitate and permit the 
adjustable mechanical coupling between the upper and lower wheels of a 
given wheel set in the vertical plane. Wheels 112 and 116 of the left side 
drive mechanism 74 as shown, in FIG. 1, with a similar number of holes 
101, although all four wheels of both mechanisms 74, 76 are identically 
provided to permit the flexibility and adjustability desired. 
In addition to lower journal 68, for each mechanism 74 and 76, there is 
provided an upper journal as at 92 in the form of a hollow metal cylinder 
which is likewise welded or otherwise suitably fixedly mounted to face 18a 
of riser 18. It rotatably mounts a shaft 96, similarly sized and 
configured, to shaft 72 for the lower wheels 80, 116. Additionally, it 
receives paired oppositely directed bearing halves 94, 95, such that shaft 
96 freely rotates about its axis coaxial with journal 92. In similar 
fashion, the upper wheel 112 is integral with shaft 96, at one end, while 
wheel 100 via its hub 98 is keyed as at 99 to shaft 96, after shaft 96 is 
projected through bearings 94. 
An important aspect of the present invention, in addition to the fact that 
the machine is formed of components which may be readily changed, i.e. the 
wheels 100, 80, 100, 112 and 116 may be replaced by other wheels having 
differently numbered mounting holes 101 passing through the same, at 
different circumferentially spaced positions, thus effecting a change in 
the timing sequence and the speed of movement of the machine across the 
turf to remove plugs therefrom, as will be described hereinafter. 
As mentioned previously, only wheels 80 of both mechanisms 74, 76 are 
positively driven via drive chains 81. Wheels 116 are shaft driven in 
unison therewith. However, the upper wheels 100, 112 of respective 
mechanisms 74, 76 are both driven and kept in time by jack shafts 104 
which mechanically connect a given upper wheel to a lower wheel in line 
therewith for respective mechanisms. The pivot mounting mechanisms at both 
ends of the jack shafts 104 are the same and interchangeable. In that 
respect, one of the key aspects of each of the mechanisms 74, 76 is the 
content of duplicate jack shaft assemblies, indicated generally at 107, 
which function to effectively mount the individual tines 108 to vertically 
in line, paired, upper and lower wheels to the inside and to the outside 
of frame angle bars 16, respectively. Each jack shaft assembly 107 is 
comprised of a jack shaft 104 having welded at its upper end hollow, 
cylindrical journal 102 and at its lower end hollow, cylindrical journal 
82. Diametrically opposite the weld connection of the lower end of jack 
rod 104 to journal 82, there is welded to that journal and projecting in 
axial alignment with jack shaft 104, a hollow metal tube 106 which is 
threaded at 106a on its inner periphery. Threadably coupled to the 
interior of tube 106 is threaded stud 109 forming a mounting component of 
each tine 108 to which stud 109 is welded. The threaded stud 109 supports 
a nut 110, backed by lock washer 111, which locks down onto the end of 
tube 106 to effectively lock the tine 108 in an axially adjustable 
position relative to tube 106 which bears the threaded end of the same. 
The mounting of both journals 82 and 102 to respective wheel sets 80, 100, 
and 116, 112 each mechanism 74, 76, as an example, is achieved utilizing a 
bolt 88, passing through the journals and through paired, opposed bearing 
halves. The bearing halves 84, 85 are very similar to the bearing halves 
70, 71 for mounting of shaft 72 and its counterparts at 94, 95, for shaft 
96, in each of the mechanisms 74, 76. In that respect, the bearing halves 
70, 71, 94, 95, and 84, 85 are T-shaped in cross-section with flanged ends 
terminating flush with the outer periphery of the journals bearing the 
same. With bearing halves 84, 85 in place, a flat washer 87 is positioned 
against the flanged end of the bearing half 84, a lock washer 86 is 
interposed between nut 90 and the flat washer 87, and the nut 90 is 
tightened down on the threaded end of bolt 88, which bolt projects through 
a given hole 101 within each wheel 80. The same arrangement is employed 
with respect to mounting of the ends of the jack shafts 104 to wheels 80 
and 116 via journals 82, and wheels 100, 112, via journals 102, 
respectively. The mounting arrangement employed for all four jack shaft 
assemblies 107 for both mechanisms 74 and 76 effects an easily demountable 
and changeable assembly as schematically illustrated in FIG. 3. 
Purposely in FIG. 3, only the jack shaft assemblies 101 and the four wheels 
80, 100, 112 and 118 are schematically illustrated for the mechanisms 74, 
76, and under conditions in which the timing sequence for the projection 
and retraction are effected so that there is normally only one tine 
entering the ground at a time. The machine 10 moves forward in the 
direction of the arrow at a relatively high rate of speed, and the tines 
108 are driven into the ground and removed under maximum power application 
conditions for the simplified drive system of the present invention. 
Keeping in mind that only the inside lower, sprocket wheels 80 of the 
mechanism are positively driven via chains 81 through drive shaft 58, as 
may be appreciated, the connection between the lower wheels and the upper 
wheels of both sets for the left and right side drive mechanism 74, 76 are 
solely effected via the jack shaft assemblies 107. The upper wheel 100, 
vertically in line with lower wheel 80, for each mechanism, knows via the 
jack shaft 107 that is to be driven but has no knowledge of which way to 
turn when journals 82, for instance, are at their bottom dead center 
position during rotation about the axis of shafts 72. However, under the 
timing mechanism created by this assembly, the journals for the jack shaft 
assemblies 107 connecting paired upper and lower wheels 112, 116 for each 
of the mechanisms 74, 76 are angularly offset from journals 82, 100 for 
the other wheel set, i.e. wheels 80, 100. As such, as indicated, given 
clockwise rotation for wheels 80, looking left to right, FIG. 3, the upper 
wheels 100, 112 for both mechanisms 74, 76 will have to rotate and be 
driven in unison in a counterclockwise direction as shown by the arrows in 
FIG. 3, for both mechanisms 74, 76. 
Additionally, as may be appreciated, the tines 108 enter and leave the turf 
under conditions in which they are perpendicular at the moment of 
penetration, at the moment of extraction, and throughout the cycle. This 
is in contrast to the prior machines of the corporate assignee, in that, 
in those machines the tines enter at one angle relative to the 
perpendicular and leave at a different angle, causing further earth 
compaction. The pivot coupling of the ends of jack shaft 104 via journals 
82, 102, respectively, for wheel sets 80, 100, is 90 degree angularly 
offset to the pivot connections for jack shaft 104 for wheel sets 116, 112 
of the same mechanism. 
In contrast to machines where power is directly applied to front or rear 
wheels, such power drive is eliminated by the present invention because 
the tines function to propel the machine forward, and the timing of 
penetration and removal of the tines is achieved by the use of a power 
driven main drive shaft 58 whose power is solely applied to a single one 
of the wheels, i.e. wheels 80 to the inside of the frame angle bars 16. As 
can be appreciated, that drive could be effected to the outer lower wheels 
116, rather than inner lower wheels 80, by forming those wheels 11 as 
sprocked wheels in lieu of wheels 80 for each of the mechanisms 74, 76. 
The eccentric connection of the jack shaft assemblies 107 to the wheel 
sets provides an effective force application from driven shafts 72 to 
tines 108 in a downward and backward direction in relation to the movement 
of the machine. This drives the tines 108 into the ground and removes them 
in a straight up/down motion which effectively propels the machine 
forward. The straight up and down motion eliminates any waddle in the hole 
which is characteristic of prior machines additionally compacting the 
sidewalls of the hole during the formation of the plug by the hollow tine 
108. 
Each tine 108, as shown in FIG. 4, is characterized by forming the tine 
from a flat plate 111 which is bent into U-shaped cross-sectional 
configuration, forming a vertical slot 115, and wherein the corners 108b 
at the intersection of side edges 108a with inclined bottom edge 108d are 
tucked in towards each other to reduce the cross-sectional area of the 
hollow tine at its entry or cutting edge 108d with an enlargement in the 
direction of the threaded stud 109 welded thereto at 113, to facilitate 
fallout of the plug (not shown) when the tine is retracted from the turf 
T. The ends 109a of the studs are beveled to cam the plug out of the 
hollow tine 108 via slot 108a. The machine with these tines 108 is not 
typical of golf course greens machines but is used on lawns, parks, etc. 
where the plugs are left on the lawn or turf since they increase the 
microbio activity to help decompose the remaining thatch. 
As may be appreciated, the throw or distance from the axis of the shafts 
72, 96 and the axis of holes 101 within all four wheels of each mechanism 
74, 76, and thus the axis of the cylindrical journals 82, 92, 114, 118, 
may vary. Typically, that throw may amount to 17/8 inches. Due to the 
circular rotation of the wheels 80, 118, 100, 112, the tine penetration is 
also on the order of 17/8 inches because when the tine 108 is in the top 
half of its swing, the tine 108 is going in the same direction as the 
machine 10 and has a forward motion and theoretically, a penetration of 
33/4 inches, and the tine should be going in the same direction as the 
machine with a forward motion of 33/4 inches. In actual practice, the 
tines achieve three inch penetration with a three inch forward motion 
without tearing the turf T or elongation of the hole H, FIG. 2. 
By using an elongated slot 111 within the tine 108, the slot can open and 
close and thus is capable pinching the soil to facilitate retraction. 
Additionally, with the pinched in corners 108b, the plug which is 
necessarily reduced during turf penetration can expand somewhat as well as 
leave the large U-shaped slot opening above the cutting edge 108d and the 
pinched in area, this action not being present where a solid tube is 
employed which has been crimped smaller on the bottom. The presence of the 
slot is quite effective along with the crimping at the corner where the 
oblique cutting edge 108d meets the vertical edges 108a of the U-shaped 
plate 111 forming the main component of the tine. 
As may be appreciated, while the upper end of the U-shaped plate 111 is 
welded to threaded stud 109 of tine 108, other arrangements may be made to 
create a tine corresponding in configuration and make up to that 
illustrated in FIG. 4. 
In setting up the left and right side mechanisms 74, 76, with the extreme 
left tine up, one of the center tines must be upm and one must be down. A 
rod (not shown) may be inserted through aligned holes 101 within bottom 
wheels 118, 80, 80 and 118, from left to right, FIG. 3. The inserted end 
of the rod should touch the center of the bolt head of bolt 80 passing 
through journal 116 of the right side tine. When this rod is parallel to 
the machine frame 12, the machine 10 is correctly timed for chain 
replacement, bearing replacement, etc. Such maintenance of timing sequence 
is necessary due to the fact that the elements of the mechanisms 74, 76 
are built up and installed under conditions requiring exact positioning 
and alignment to insure the initial creation of proper timing and the 
maintenance of the same. 
The rotational direction of wheels 80 should be rotating in a 
counterclockwise direction when viewed from left to right, FIG. 3. 
It should be appreciated, that the upper wheels 100, 112 for each mechanism 
74, 76 are maintained in time by offsetting the connection links for the 
jack shaft assemblies 107 to respective wheels 100, 112 by some angular 
offset, up to but not including 180 degrees. The illustrated embodiment 
shows 90 degree offset since there are four jack shaft assemblies forming 
connecting links between the four upper and lower, in line sets of wheels. 
If the machine is widened, utilizing two additional jack shaft assemblies, 
one to each side, the offset of the throws may be by 45 degrees rather 
than 90 degrees by using a different pattern of holes 101, 45 degrees 
apart. Additional holes 101, other than those at 90 degrees as at 45 
degrees, 60 degrees, etc., may be added to the wheels shown to provide for 
this circular effect. If the number of tines were doubled to eight, four 
to a side, it would be necessary to return to the 90 degree offset, or 
alternatively, a series of 45 degree offset holes would suffice. It should 
be additionally appreciated that the lower wheel of each mechanism 74, 76 
are driven at relatively high speed by the proper selection of pulley 
sprocket and sprocket wheel diameters with the lower wheels 80 and 116 for 
each of the mechanisms 74, 76 constituting highly effective high speed 
flywheels, providing more than adequate force for penetrating the hollow 
tines 108 into the turf and retraction therefrom in timed sequence, even 
when the turf is relatively dry and hard under conditions in which the 
operation insures that action at high speed with self-propulsion of the 
machine 10. Using the mechanisms 74, 76 as shown via the drive system of 
pulleys and sprocket wheels, the lower wheels 80, 108 of both left and 
right mechanisms rotate at 400 rpm. In the illustrated embodiment, one rpm 
advances the machine forward six inches by doubling the rpm from the 200 
rpm of prior machines of the corporate assignee. The present invention 
increases appreciably the penetration force driving the tines 108 into the 
turf. 
As may be appreciated by reference to FIGS. 1, 5, 6, 7 and 8a and 8b, the 
machine of the present invention utilizes a two position handle assembly 
for locking the handle in either raised or lowered position to permit tine 
penetration into the turf and plug removal, or prevent the same 
alternatively. With the handle assembly lowered relative to the rear end 
of the chassis, the effect is to raise the rear end of the chassis 12 and 
with the handle assembly locked in this position, the chassis 12 may be 
pushed across the turf rotating on its front and rear wheels. 
The adjustable locking of the handle assembly may be appreciated further by 
reference to FIGS. 6, 7 and 8a, 8b. In FIG. 6, a handle assembly is 
indicated generally at 120 and is comprised of laterally spaced handle 
assembly frame members 122 which may be angle bars and terminating at 
their lower ends in sections 122b which are at an obtuse angle to the 
frame members 122 proper. The lower ends of the handle assembly frame 
members 122 are pivotably mounted to respective sides of the machine and 
specifically to chassis angle bars 16 by means of brackets 130 welded to 
the angle bars 16, within which pivot pins 132. Pins 132 are fixed to the 
ends 122b of handle assembly frame members 122 and rotate within holes 133 
of the brackets 130, through which the pins project. Alternative means may 
be employed. However, it is important that the pivot axis for handle 
assembly frame members 122 be in general alignment with the pivot axis for 
the paired depth adjustment lock bars 32. Reinforcing struts 128 may be 
welded at respective ends to portions of the handle assembly frame members 
122 spanning the bend area 122c of those frame members. Further, angle arm 
or transverse cross bar 134 is welded at respective ends to the laterally 
opposed handle assembly frame members 122. The handle assembly 120 has 
welded, across those upper ends 122a of the frame members 122, a handle 
bar 124. Preferably, a pair of struts 126 are, in turn, welded at one end 
to the ends of the handle bars 124 and at opposite ends to the sides of 
the handle assembly frame members 122. The cross bar or angle arm 134 
mounts at its center, as best seen in FIGS. 8a, 8b, a metal sleeve or 
cylinder 136 which may be welded to the upper face of the angle bar 134 
and through which passes a pin or plunger 138. A hole drilled transversely 
through pin 138 carries a cotter pin as at 146 to limit movement of the 
pin 138 in a direction towards chassis 12. A U-shaped hook 140 is welded 
to the outside of the sleeve or cylinder 136 and a hook 144 is fixed to 
the end 138b of the pin 138. A tension coil spring 142 is mounted at 
respective ends to hooks 140, 144, so as to bias the pin 138 in the 
direction of arrow 143, FIG. 8a. 
As may be seen in FIG. 8a, under conditions where the pin 138 is within 
slot 41 of locking plate 39, handle assembly 120 is locked in raised 
position relative to chassis 12. The cross bar or angle arm 134 
additionally mounts to opposite sides thereof rear wheel axle support bars 
137 which are welded at one end to cross bar 134 and its opposite ends to 
an axle 139 for mounting paired rear wheels 154 to each side of the 
machine. A second pair of axles support bars 141 extend from axle 139, 
being welded thereto, at that end, directly to respective frame members 
122 and are welded at their upper ends to frame members 122. A rigid axle 
mount is thus provided for the handle assembly 120. The handle assembly 
120 further includes a pin release mechanism which consists of a wire 
control rod 146. Rod 146 terminates in a right angle portion 146a at its 
lower end which projects through a hole within pin 138 at end 138b beyond 
the cotter pin 146. After passing through the hole within pin 138, a 
washer 148 is mounted thereto and the 146a of the control rod may be 
peened over to complete the coupling. The opposite end of the control rod 
146 is bent at right angles thereto, and projects within a hole 151 of an 
operating lever 150. Lever 150 is pivot mounted by a pin 152 projecting 
from the handle bar 124 such that rotation of the lever 150, as shown by 
arrow 153, in a counterclockwise direction, FIG. 7, functions to retract 
the pin 138 against the bias of coil spring 142 and to remove the pin end 
138a from slot 41 of latch plate 39, FIG. 8a, or to remove the end 138a of 
the pin 138 from a similar slot 47 within the lower locking plate 45, FIG. 
8b. Coil spring 142 normally biases the pin in projected, rather than 
retracted, position. During changeover from the tine penetration and 
chassis lowered position, as shown in FIGS. 1 and 6, to a tine retracted 
and chassis raised position, all that is necessary is that an initial 
movement be given to lever 150' in a counterclockwise direction as shown 
by arrow 153 in FIG. 7, at which point the handle assembly frame members 
122 can pivot clockwise, FIG. 6, as indicated by arrow 145. Upon releasing 
of the lever 150, pin 138 again moves forwardly within cylinder or sleeve 
136 under the bias of coil spring 142. The end 138a of the pin 138, in 
moving towards locking plate 45, will strike the camming portion 45a of 
locking plate 45, causing the pin 138 to retract against the bias of coil 
spring 142 until the end 138a of the pin 138 reaches transverse slot 47, 
whereupon the spring bias causes it to project into the slot to lock the 
lower ends 122b of the handle assembly frame members 122 generally in line 
with the paired bars 30. The effect of this is to raise all of the tines 
108 above the turf and prevent their penetration, even with the engine 
operating. 
To again effect turf penetration, the lever 150 must be pivoted 
counterclockwise, FIG. 7, removing end 138a of pin 138 from slot 47 within 
the lower locking plate 45. This permits the handle assembly 120 to rotate 
counterclockwise to the position shown in FIG. 6, whereupon, in so moving, 
the end 138a of pin 138 (with lever 150 released) contacts the angled 
camming portion 39a of the locking plate 39, forcing the pin 138 to 
retract against the bias of spring 142 which is stretched during this 
action to the point where the end 138a of the plunger 138 rides across the 
face of latch plate 39 until it reaches the transverse slot 41, whereupon 
the end 138a of pin 138 projects into the slot under spring 142 bias. 
It should also be kept in mind that the cross bar 134 is welded to the 
handle assembly frame members 122 at a position such that either it or the 
projected end 138a of pin 138 will impinge against the stop 43 to prevent 
further pivoting of the frame members 122 beyond a position where their 
lower ends 122b are essentially in line with the pair of depth adjustment 
lock bars 32. The degree of angulation between chassis raised and chassis 
lowered positions can be effectively changed, as mentioned previously, by 
rotation of the locking nuts 137 on the threaded end 34a of the depth 
adjustment rod 34 to permit the depth adjustment rod 34 to be adjusted 
within the hole within latch adjustment plate 36. 
While the invention has been particularly shown and described with 
reference to a preferred embodment thereof, it will be understood by those 
skilled in the art that various changes in form and details may be made 
therein without departing from the spirit and scope of the invention.