Method and apparatus for retrieving objects from the ground

A method and apparatus for collecting flat or semiflat materials while simultaneously retrieving bottles and cans includes a ground engageable rotating drum (52) with a plurality of fingers (60) extending radially from the drum. A plurality of toothed discs (210) is rotatably mounted on a shaft and driven in conjunction with the rotation of the drum in a direction opposite that of the drum. The toothed discs (210) are positioned adjacent to but above ground level during operation of the apparatus and assists in the engagement and movement of objects by the drum and fingers to a collection location (32). A plurality of belts (130) is engaged between pulleys (212) mounted intermediate of the toothed discs (210) and corresponding pulleys (126) on a shaft spaced from the toothed discs. The belts are positioned on the trailing side of the drum and above the toothed discs and assist in engagement and movement of objects by the drum and fingers to the collection station. Stripper bars (180) assist in dislodging objects from between the fingers of the drum. A second assembly of a plurality of toothed discs (220) is mounted on a shaft and driven in conjunction with the rotation of the drum in the same direction of the drum. This second disc assembly is positioned near the top side of the drum and adjacent the structure for dislodging objects from the drum fingers. Rotation of this second disc assembly assists in directing objects carried to the top side of the drum to the collection station.

TECHNICAL FIELD 
The present invention relates to a method and apparatus for retrieving and 
collecting objects from the ground, and more particularly for such a 
method and apparatus used in litter retrieval. 
BACKGROUND ART 
Many man-hours are expended in the collection of litter and other debris 
from large community areas such as along streets and highways, parks, 
playgrounds, along beach areas and open commercial areas. Because of the 
difficulty of designing a machine which will collect the various types and 
sizes of litter and operate over various types of ground surfaces, manual 
retrieval has often been relied on. Moreover, manual retrieval methods are 
slow and many times are ineffective, particularly where large areas must 
be patrolled. 
Machines have been designed to supplement or replace the need for manual 
retrieval of litter. An effective apparatus for litter retrieval is 
disclosed in U.S. Pat. No. 3,807,154, to the inventor of the present 
invention, issued Apr. 30, 1974. This patent discloses the use of a towed 
apparatus having a rotatable drum which is rotated upon ground engagement. 
A plurality of flexible fingers extends radially from the drum and has a 
particular configuration for receiving bottles and cans therebetween 
during the movement of the apparatus along the ground surface. Bottles, 
cans and similar objects engaged by the drum and fingers are collected in 
a hopper after being stripped from the fingers. 
Although the device described in U.S. Pat. No. 3,807,154 is capable of 
retrieving some objects, such as bottles and cans, the effectiveness of 
the device has been less than completely satisfactory for other types of 
litter. Where the particular object cannot be grabbed between the 
resilient fingers extending from the drum, then the apparatus may fail to 
collect the debris. 
It is critical that an apparatus for collecting litter be able to retrieve 
bottles, cans and objects having arcuate outer surfaces of a form 
retaining nature, as well as simultaneously collecting materials such as 
paper, and various containers made thereof, textile materials and other 
flat or semiflat objects. Thus, the need has arisen for a device which can 
simultaneously collect both bottles and cans, which make up a large 
portion of the litter in large public and private areas, as well as other 
debris of differing shapes and materials. 
Prior apparatus with respect to these types of devices have also failed to 
properly disclose a means for supporting the weight of the drum and finger 
assembly without sustaining damage to the fingers. Further, such support 
must not permit an excessive "dead space" which is not engaged by the 
fingers where the device encounters irregular terrain. 
DISCLOSURE OF THE INVENTION 
The present invention provides an improved method and apparatus for 
collecting flat or semiflat materials such as various paper, textile 
materials and the like, while simultaneously retrieving bottles and cans 
and other objects having cylindrical form retaining outer structures. In 
accordance with one embodiment of the invention, an apparatus has a ground 
engageable rotating drum with a plurality of fingers extending radially 
from the drum. A plurality of toothed discs is rotatably mounted on a 
shaft and driven in conjunction with the rotation of the drum in a 
direction opposite that of the drum. The toothed discs are positioned 
adjacent to but above ground level during operation of the apparatus and 
assist in the engagement and movement of objects by the drum and fingers 
to a collection location. 
In one form of the invention, the toothed discs are positioned intermediate 
of circumferentially and radially projecting rows of fingers extending 
from the drum. The outer circumference of the toothed discs is 
substantially tangential to the outer circumference defined by the tips of 
the fingers extending from the drum. The toothed discs are located on the 
trailing side of the drum from the point of ground contact. 
In accordance with a further embodiment of the invention, a plurality of 
belts is engaged between pulleys mounted intermediate of the toothed discs 
and corresponding pulleys on a shaft spaced from the toothed discs. The 
belts are positioned on the trailing side of the drum and above the 
toothed discs and assist in the engagement and movement of objects by the 
drum and fingers to the collection station. 
In accordance with still a further embodiment of the invention, the 
apparatus of the present invention further includes a means for dislodging 
objects from between the fingers of the drum. A second assembly of a 
plurality of toothed discs is rotatably mounted on a shaft and driven in 
conjunction with the rotation of the drum in the same direction of the 
drum. This second disc assembly is positioned near the top side of the 
drum and finger assembly and adjacent the structure for dislodging objects 
from the drum fingers. 
The second disc assembly is positioned such that the discs are intermediate 
of spaced rows of teeth positioned along the length of the drum. As 
objects are directed to the second disc assembly, and as the objects are 
dislodged from the drum fingers, the objects are directed by the rotation 
of the second disc assembly to a collection station. In one embodiment of 
the invention, the objects are carried to the collection station after 
engagement by the second disc assembly by a conveyor driven in conjunction 
with the rotation of the drum. 
In the method of the present invention, objects are retrieved from the 
ground by moving the ground engageable drum over the ground surface. Upon 
rotation of the drum, objects are engaged between fingers and are moved 
upwardly with the drum's movement. A plurality of discs is rotatably 
mounted on a shaft adjacent the drum and finger assembly. The discs are 
driven in conjunction with the rotation of the drum in a direction 
opposite that of the drum. With the discs positioned adjacent the drum and 
finger assembly and slightly above ground level, litter, such as 
relatively flat paper articles and the like, is engaged by the discs and 
moved into and toward the drum and fingers. The objects engaged between 
the fingers are stripped from the fingers by a stripper bar mounted 
intermediate of the rows of fingers and adjacent the drum. 
The objects directed between the toothed disc and the fingers are carried 
in the direction of travel of the fingers and drum using a plurality of 
belts mounted between the toothed disc shaft and a shaft spaced therefrom 
and adjacent the rotation of the tooth and drum assembly. The belts 
provide a semiconveyor arrangement to further direct objects along the 
path of rotation of the drum and to the collection location. 
A plurality of toothed discs is also positioned adjacent the drum in the 
area of structure for stripping objects from between the fingers. This 
second set of toothed discs is rotated in the same direction as the drum 
and directs the objects to the collection location. 
In accordance with another embodiment of the invention, the fingers 
extending from the drum are positioned in rows spaced along the 
longitudinal length of the drum. The fingers are formed of a resilient and 
flexible material, such as rubber, having a metal base attached to the 
drum. One row of fingers, however, positioned approximately one quarter of 
the length of the drum from each end of the drum, are replaced by spokes 
formed with a rigid inner structure with a resilient cover thereon. These 
two rows of spokes provide support to the weight of the drum as the drum 
traverses the ground surface. As a result of the positioning of these two 
support rows of spokes, a minimum of ground area is left uncovered where 
the apparatus encounters irregular terrain.

DETAILED DESCRIPTION 
The apparatus 20 of the present invention for retrieving objects from the 
ground includes a frame structure 22 including horizontal beams 24 and 26 
spaced by transverse struts 28 and 30. A material collection hopper 32 is 
supported behind frame 22 and an axle assembly 34 supports the frame and 
collection hopper for movement over a ground surface on wheel and tire 
assembly 36. 
The structure for retrieving objects from the ground includes a rotatable 
drum assembly 50 consisting of a drum 52 supported by arms 56 for rotation 
about an axle 54. A plurality of receiving fingers 60 is attached to and 
extends radially from drum 52. 
A toothed disc assembly 70 is supported adjacent drum assembly 50 and 
behind the drum assembly near ground engagement. A side shield 72 serves 
in part as a structure for supporting toothed disc assembly 70 from frame 
22. Toothed disc assembly 70 includes axle shafts 76 and 78 driven by an 
appropriate gear box operating from axle shaft 80 which is in turn driven 
by the rotation of drum assembly 50. Axle shaft 76 also drives a conveyor 
assembly which will be described hereinafter in greater detail. The drive 
provided therefor requires a chain guard 90 seen in FIG. 1. A chain guard 
92 also is provided to protect the chain drive from drum assembly 50 to 
gear box axle shaft 80. A further chain guard 96 is shown in FIG. 1 and 
protects a drive chain from drum assembly 50 to a kicker assembly as will 
be described hereinafter in greater detail. 
A forward wheel assembly 100 is attached at the point of connection of 
horizontal beam 24 and transverse strut 30 and includes a free wheeling 
wheel unit 102. A coupling assembly 104 is attached to the forward end of 
horizontal beam 24 and provides an appropriate hitch structure 106 for 
attachment of the apparatus to a tow vehicle such as truck 108 shown in 
FIG. 1. 
A forward shield 110 partially encircles drum assembly 50 to provide 
protection around the drum assembly. This shield may be left off to 
provide visibility of the drum during rotation. Alternatively, the shield 
may consist of a wire screen to permit the operator to view the drum 
operation. A shield 112, having a wire screen top, also extends from the 
area of drum assembly 50 to collection hopper 32. 
FIG. 2 shows the retrieval apparatus 20 with the side shielding, guards and 
the like removed to reveal the inner structure of the device. FIG. 3 shows 
the pickup structure in perspective view without the shielding and other 
attendant structure. Referring to FIGS. 2 and 3, it can be seen that drum 
assembly 50 includes a cylindrical drum supported for rotation about axle 
54 by arms 56. A plurality of fingers 60 extends radially from drum 52 and 
is positioned in rows spaced along the longitudinal length of the drum. 
Fingers 60 are also positioned such that the fingers are aligned along the 
length of the drum as viewed from the side. However, it will be 
appreciated that these fingers may be staggered so as not to be aligned 
along the longitudinal length of the drum as required to complete the 
object of the present invention. 
Referring specifically to FIG. 2, a sprocket 120 is attached for rotation 
with axle 54 and drives shaft 80 at gear box 122 by way of chain 124. The 
rotation of shaft 80 of gear box 122 in turn drives shaft 76 to rotate a 
plurality of pulleys 126 in the direction indicated by arrow 128. The 
rotation of shaft 76 is communicated by way of flexible belts 130 to drive 
shaft 78 of toothed disc assembly 70. Shaft 76 also has an appropriate 
sprocket for driving a conveyor assembly 140 in the direction shown by 
arrow 142 by driving lower shaft 144 by way of chain 146. Conveyor 
assembly 140 includes an upper shaft and roller assembly 150 and a lower 
roller assembly 152 driven by the rotation of shaft 144. A conveyor belt 
154 is entrained around rollers 150 and 152 and carries a plurality of 
spaced material carriers 160. 
Although not specifically shown, disc assembly 70 and gear box 122 are 
mounted on a floating frame which is movable on an arc having a center at 
the axis of drum 52. This permits arcuate movement of disc assembly 70 
upon engagement of objects, such as large rocks or stumps, during 
operation. A travel of about six to ten inches is provided in the 
preferred embodiment. 
A material director 164 is positioned immediately above gear box 122. The 
director includes an arcuate first leg 166 which follows the curve defined 
by the outer tips of fingers 60 and is slightly spaced therefrom. A second 
leg 168 is joined to the upper end of leg 166 and angles rearwardly toward 
conveyor assembly 140. 
A plurality of strippers 180 extend downwardly from a support bar 182 and 
is positioned in between the rows of fingers extending from drum 52. The 
lower ends of strippers 180 are in close proximity to drum 52 and almost 
tangential thereto. Preferably, these strippers are formed of metal angles 
having notches 183 (FIG. 3) cut in the sides to permit close positioning 
to fingers 60. 
A kicker assembly 190 is located immediately rearwardly of strippers 180. 
The kicker assembly includes a rotatable shaft 192 driven by a chain 194 
rotated from an appropriate sprocket attached to axle 54 of drum assembly 
50. During operation of the unit, rotation of kicker assembly 190 is in 
the direction of arrow 200. 
Referring now to FIG. 3, both toothed disc assembly 70 and kicker assembly 
190 are shown in greater detail. Toothed disc assembly 70 includes lower 
shaft 78 having a plurality of toothed discs 210 positioned along the 
length of the shaft. Each disc is separated from the adjacent disc by a 
pair of pulleys 212. Similar pulleys 126 are attached to shaft 76 and 
flexible belts 130 are engaged between pulleys 126 and corresponding 
pulleys 212 on shaft 78. 
Referring still to FIG. 3, kicker assembly 190 includes a plurality of 
toothed discs 220 of a design similar to discs 210. Discs 220 are 
separated by spacers 222 to provide approximately the same spacing as 
between discs 210 on shaft 78. The spacing and positioning of discs 210 
and 220 position the discs intermediate of the rows of fingers 60. 
As can be seen in FIG. 4, the tips of discs 210 are positioned relative to 
fingers 60 such that the outer circumference of discs 210 is approximately 
tangential to the outer circumference defined by the tips of fingers 60. 
With respect to the positioning of discs 220, they are slightly more 
inboard and pass between fingers 60. 
As can be seen in FIGS. 3 and 4, belts 130 are positioned slighty radially 
outboard from the tips of fingers 60. Because of the relatively close 
spacing between belts 130, they provide a conveyor effect as will be 
discussed hereinafter in greater detail. The lower edge of leg 166 of 
material director 164 is substantially in line with and immediately above 
the upper point of travel of belts 130. 
Referring to FIG. 5, the pulleys 212 and discs 210 are mounted onto shaft 
78 by using a compression fit supplied by fitting 230. Fitting 230 has a 
sleeve 232 for engaging the endmost disc 220 and an internal thread 234 
for mating with threads 236 on shaft 78. By engaging fitting 230 onto axle 
shaft 78, a compressive force is applied to pulleys 212 and discs 210 to 
effect the transmission of rotative force from shaft 78 to the discs and 
pulleys. However, by controlling the torque and the compression load 
applied by fitting 230, the discs and pulleys may be permitted to slip in 
the case of engaging a blockage during operation. 
FIG. 6 illustrates a section view of one of the fingers 60. The finger 
includes a metallic base shaft 240 which is attached through the sidewall 
of drum 52 using a nut 242 on the inside surface. The end of shaft 240 is 
threaded to receive nut 242 thereon. A shoulder on the end of shaft 240, 
larger than the aperture through the sidewall of drum 52, permits the 
mounting of the fingers as shown in FIG. 6. A specially shaped body 
portion 244 is attached on the end of shaft 240. Body portion 244 is 
preferably formed of a resilient material, such as neoprene. The body 
portion includes a conically shaped lower end 246 forming a camming 
surface 247 with a maximum diameter at 248 and having an arcuate 
longitudinally extending concave article holding surface 250 extending to 
the radially inwardly end of the body portion and terminating in a 
circular rim at 252 of a diameter less than that of the lower end at 248 
but greater than that of the central region of the article holding 
surface. It will be seen that no portion of the article holding surface 
250 has a diameter greater than the diameter of 248. 
In operation of the unit of the present invention, fingers 60 and spokes 
278 of drum assembly 50 engage the ground surface as the apparatus is 
pulled by the tow vehicle. The weight of the drum is substantially 
supported by spokes 278. The engagement with the ground surface causes the 
drum assembly 50 to rotate clockwise as seen in FIGS. 1 and 2. As the drum 
rotates, it drives, by way of gear box 122, toothed disc assembly 70. By 
driving shaft 76, shaft 78 and discs 210 are driven by belts 130. Rotation 
of discs 120 is in a counterclockwise direction as seen in FIG. 2. 
As the drum rotates and engages cans or bottles lying on or embedded in the 
ground surface, the cans or bottles will be forced between adjacent 
fingers. The objects first engage camming surface 247 and upon the flexure 
of the body portion 244 of the fingers, are then forced into the article 
holding area immediately above the camming surface. Because the bottle or 
can may be positioned in any random fashion, the bottle may be engaged by 
two or more fingers as the drum rotates. In any event, the lateral 
deflection of the fingers will permit the bottle to be received between 
the fingers and then retain the bottle or can within the grasp of the 
fingers as the drum continues to rotate. 
In the prior art devices, a positive means of lifting various sizes of 
paper and other products other than bottles and cans has not been 
provided. However, the present invention provides toothed disc assembly 70 
for this purpose. As the apparatus traverses the ground surface, discs 210 
act to lift paper and other litter into the area between the toothed disc 
assembly and the ends of fingers 60. As a result of the counterrotation of 
these two components, paper and other similar debris are carried upwardly 
above discs 210 into contact between belts 130 and the outer tip of 
fingers 60. It will be appreciated that it is not necessary that the paper 
or other debris be spiked by the fingers but rather the material may 
merely be conveyed upwardly as a result of the entrapment between discs 
210, belts 130 and fingers 60. Of course, some paper may be spiked by 
fingers 60 which would provide even more positive transmission of the 
litter upwardly as the drum rotates. 
As the litter reaches the upper point of belts 130, it continues to move 
upwardly between fingers 60 and material director 164. 
It has been found that the present apparatus must be moved at a sufficient 
speed to be economical. At higher speed, centrifugal force tends to 
dislodge the litter trapped between the fingers. In the present invention, 
disc assembly 70 and material director 164 act to prevent the dropping of 
litter from engagement between the finers of the drum assembly. Where disc 
assembly 70 is not employed, material director 164 will be extended 
downwardly to the area occupied by disc assembly 70 to prevent the loss of 
litter from engagement by the fingers due to centrifugal force. 
This alternative arrangement is shown in FIG. 10 wherein material director 
164' has a lower leg 166' which extends behind drum assembly 50 from upper 
leg 168 to a point just above the ground surface. A foot skit 166" is 
attached to leg 166'. The material director is mounted by way of a 
floating frame which is movable on an arc having a center at the axis of 
drum 52 upon contact with objects encountered during operation. 
At the upper point of their movement, bottles and cans and other debris 
which are grasped by the fingers are stripped therefrom upon engagement of 
strippers 180. This litter, as well as other litter which is carried to 
this upper point, is engaged by kicker assembly 190 rotating in a 
clockwise direction as seen in FIG. 2. The rotation of kicker assembly 190 
directs the debris rearwardly where it is picked up by conveyor assembly 
140 and carried upwardly into collection hopper 32 for later disposal. 
Thus, the present invention provides a structure for not only positively 
collecting bottles and cans, but also a structure which simultaneously 
provides a very effective means for directing other debris of virtually 
all sizes and material upwardly with the movement of drum assembly 50 and 
thereafter onto a conveyor for disposal into a collection hopper. 
The toothed disc assembly of the present invention also effectively 
operates in various terrains, including grass areas of differing heights, 
as well as paved areas or even gravel or sand areas. The toothed discs 210 
operate to dislodge the litter and carry it upwardly for subsequent 
transmission and conveying by belts 130 between the belts and the fingers 
60. This arrangement operates to lift debris and litter without 
necessitating the spiking of the material which is not always possible 
because of the material's composition or configurations. Thus, the present 
invention provides an extremely effective way of collecting the litter and 
debris without this requirement. The kicker assembly, incorporating a 
similar toothed disc arrangement, then acts to project the litter and 
debris which has been lifted by the unit to an area for removal to a 
collection hopper. 
Although the present disclosure has described discs 210 and 220 as having 
the same configuration, it will be appreciated that varying configurations 
can be used for either or both of these discs. The present illustration is 
merely a disclosure of the best mode now known to the inventor but other 
toothed designs, ranging from a very fine tooth design to an even broader 
design, could be employed. Further, a disc composed of radial splines 
could also be substituted for the design disclosed. However, in the 
primary embodiment of the invention, the apparatus is designed to minimize 
the collection of unwanted debris such as grass, twigs, pebbles or rocks. 
Because the drum assembly of the present invention engages the ground as it 
rotates, substantial load is placed upon the fingers to support the weight 
of the apparatus during operation. In the present invention, the two rows 
of spokes spaced inboard from the ends of drum 52 approximately one 
quarter of the length of the drum are of a special design to accommodate 
the weight of the apparatus. These spokes 278, shown in section in FIG. 7, 
include a rigid shaft 280 covered by a resilient covering 282, such as 
neoprene. The attachment end of the spoke 278 is threaded at 284 for 
attachment to the sidewall of drum 52. As can be seen in FIGS. 8 and 9, 
when the apparatus of the present invention traverses a crown (FIG. 7) or 
a valley (FIG. 8), very little "dead space" is provided. The dead space 
referred to is that area where the fingers are lifted from the ground 
surface and therefore may fail to collect debris or litter on the ground. 
As the apparatus of the present invention encounters a crown area, only a 
very small portion below the outer edges of the device is uncovered. Where 
the device encounters a valley, only a very small central portion of the 
area over which the apparatus passes is left uncovered. Thus, the present 
invention provides spokes which support the drum, especially over very 
hard surfaces where otherwise the more resilient fingers would be 
seriously damaged, while at the same time minimizing the dead space where 
the apparatus traverses an irregular terrain. 
While the apparatus in the present invention has been described as used in 
the retrieval of litter, it has been found that the machine is ideally 
suited for collecting agricultural products from the ground. For instance, 
the apparatus may be used in the retrieval of corn which has been knocked 
to the ground during combining operations or as a result of the weather. 
In the use of the present invention to collect agricultural products from 
the ground, the apparatus may be used either with or without the toothed 
disc assembly 70. However, because of the tendency, as a result of 
centrifugal force, for the product to be dislodged from the fingers prior 
to collection, material director 164 serves to prevent the product from 
being dropped from the fingers prior to being discharged above the shield 
where the material is then directed to conveyor assembly 140. 
Although preferred embodiments of the invention have been described in the 
foregoing Detailed Description and illustrated in the accompanying 
Drawings, it will be understood that the invention is not limited to the 
embodiments disclosed, but is capable of numerous rearrangements, 
modifications and substitutions of parts and elments without departing 
from the spirit of the invention. Accordingly, the present invention is 
intended to encompass such rearrangements, modifications and substitutions 
of parts and elements as fall within the spirit and scope of the invention 
.