Note: Descriptions are shown in the official language in which they were submitted.
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CROP GATHERING ~DEAD AND BELT,
SPROCXET, AI~D SHEAVE THE~EFOR
The abstract is not to be taken as li~iting the inventiGn of
this applicatisn and in order to understand the full nature and
extent of the technical disclosuxe of this application reference
~ust be made to the accoI~anying drawnng and to the following
detailed description.
This invention relates to a crop gathering head and ~.ore
particularly to a belt, sprocket and sheave system for use in a
crop gathering machine.
There are various configurations of ~achinRs to be used in
harvesting of crops such as corn in which the stalk of the crop is
drawn into the forward end of the gathering portion of the
ha~vester by ~ans of metallic chains including tines or fingers
attached thereto. The stalk of the co m enters a narr~ slot which
is elongated in the fore and aft direction of the machine, i.e.
parallel to the diretion in ~llich the machine moves. The slot is
of sufficient width to accept the stalk but not permit the ears o~ ~ _
corn to fall thr~gh. A m~chanism mounted bel~ the planar faces
form m g the slot draws the stalk downwardly through the slot
thereby separating the ears from the stalk. After sep æ ation, the
~_r ears are conveyed by means of a pair of opposed ~hains to the rear
of the gathering head for fur~her processing; e.g., rem~val of th~
- husk and separation of the corn kernels fron the ear in known
~a~er.
Prior art gathering mec~anisms which em~loy metallic chain and
sprockets, although they have been used wi~h considerable success,
generate a considerable a~ount of noise and vibration and of course
are subject to rusting and loss of tension as they wear at thei~
links. Additionally such metallic chains are likely to damage the
remainder of ~he harvesting ma~hine should the chain or a portion
of it pass through the ~,ech2nism. Also, use of ~etallic gathering
hains at ground speeds of the harvester in excess of about four
,~;
~ -2-
(4) miles per hour results in very rapid wear of the
chains. To extend their service life, metallic chains
require periodic lubrication.
An aspect of the invention is as follows:
A sprocket for accepting a belt having a single
line of drive lugs for complementary engagement with a
single line of circumferentially aligned oppositely
facing alternating cavities comprising a plurality of
equally spaced apart, radially projecting teeth
separated by first and second cavities, said first
cavities being open only to the first side of the
sprocket, said second cavities being open only to the
second side of the sprocket, each cavity being defined
by the fore and aft surfaces of a pair of adjacent
teeth and a radially projecting flange portion that
extends circumferentially between a pair of adjacent
teeth and an arcuate conical bottom surface, sloping
toward the axis of rotation in a direction away ~rom
said flange portion each cavity having an axial depth
substantially greater than one-half of the axial
dimension of the sprocket.
The features and advan~ages of the invention will
be better understood from consideration of the
following detailed description taken in conjunction
with the accompanying drawings in which primes (e.g. l
versus 1' are used to distinguish between various
embodiments:
Figure 1 is a top plane view of a crop gathering
head embodying the invention;
Figure 2 is an enlarged longitudinal section of a
portion of a pre~erred embodiment of a belt according
to the invention;
Figure 3 is an enlarged sectional view illustrating
a drive sprocket according to the invention with the
belt of the invention engaged therewith being shown in
transverse section;
~B' '
Figure 4 is a slde view of a drive sprocket accord-
lng to the invention;
Figure 5 is a sectional view of a drive sprocket
according to the invention, the section being taken
along line 5-5 of Figure 4,
Figure 6 is a ~side view of an idler sheave accord-
ing to the invention; and
Figure 7 is an end view of the sheave of Figure 6
with the belt of the invention engaged therewith being
shown in transverse section.
Referring to Figure 1 there is shown a crop gather-
ing head 10 that includes a pair of synchronously
driven belts llA, 12A. Belts 11,12 run parallel to
one another in a common plane located above the metal
flanges 14 which form the slot 15 of the crop gathering
head 10. The direc~ion of travel of belt 11 is counter-
clockwise and while the direction of travel of belt 12
is clockwise thus the belts 11 and 12 work in concert
to transport ears of corn (not illustrated) from the
forward end 16 to the aft end 17 of the crop gathering
head 10 after the ears have been snapped off by withdraw-
ing the stalk downwardly through the slot 15 between
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flanges 14. Belts 11 and 12 as well as their driving systems are
identlcal except for their arrangement on the ~achine; one being
the mirror im2ge of the other.
Peferring now to Figure 2 in addition to Figure 1, each belt
ll, 12, 11', 12' includes at top surface 18, 18' and a bottom
surface 19, 19'. The top surface 18, 18' is the surface of the
belt ll, 12, ll', 12' that is directed away from the drive sprocket
30 and idler sheave 50. The bottom surface 19, 19' is that surface
of the belt ll, 12, 11', 12' nearest to the dri~e sproeket 30 and
sheave 50. The top surfaces 18, 18' of belts 11, 11' and 12, 12'
are adjarent to and opposed to one another over the crop ga~hering
flanges 14. The top surface 18, 18' of each gathering belt 11, 12,
11', 12' includes a pluxality of identical cleats 20, 20' of
elastomeric material. Each cleat 20, 20' projects substantially
perpendicularly from the top surface 18, 18' of its respective
belt. In a preferred embodiment each cleat 20' when viewed in
longitudinal section of the belt 11', 12' (as shown in Figure 2) is
of t ~ ar configuration with the base of the triangle being
joined to the top surface 18' of the belt. Each cleat 20~ when
~iewed in longitudinal section of the belt ll' or 12' has a
lcngitudinal dimension X at its b ce. The cleats 20' are uni~ormly
spaced apart ~rom one another by their pitch Y. The tenm pitch as
employed herein means the distznce between succeeding lugs or
cleats as ~asured from a given po~nt on one cleat to the identical
point on the next cleat or lug. In the particularly preferred
e~bodi~ent shown each cleat 20' when viewed in longitudinal section
of the belt 11', 12' is a hollow triangle one leg 21 of the
triangle extends from the base of the cleat 20' from a point
opposite the location of z driving lug 24', the other leg 22 of
the triangulzr configured cleat 20' extends from a point opposite
~he next driving lug 24A'.
The cleats 20, 20' possess sufficient stiffness so as to
positively convey the ears of corn from the forward end 16 to the
aft end 17 cf the gathering head 10. The hollow trian~ulzr
configuration 20' shown acco~lishes this with a minim3m æ ~unt of
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elasto~eric material. It is understood that other cleat
configurations will work, however. Due to the inherent resilience
and flexibility of the elascomeric material of which the cleats are
formed, should the harvesting machine become ja~med the cleats 20,
20' will then deflect without being damaged or cauLsing daLmage to
other p~rts of the crop gathering head 10.
A plurality of driving lugs 241 24' of elastomeric ~aterial
project from the bottom surface 19, 19' of the belt 11, 12, 11',
12'. Each driving lug 24, 24' projects generally perpendicularly
relative to the bottcm surface 19, 19' of the belt 11, 12, 11' or
12'. Each driving lug 24 ~nen viewed in a longitudinal section of
the belt 11, 12, 11' or 12' is of trapezoidal configuration with
f the base of the trapezoîd joined to the bottom surface 19, 19' of
tne belt 11, 12, 11' or 12' Each lug 24, 24' has a lG~gitudin21
din~sion at its base of A. Succeeding lugs 24, 24' are spaced
a?art from one another i-n the longitudinal direction of the belt
11, 12, 11' or 12' by lug pitch ~.
.Referring now to Figure 3 it is seen that each of the driving
- lugs 24' when viewed in a transverse section of the belt 11' or 12'
is of trapezoidal configuration with.the base of the trapezoid
joined to the bottom surface 19' of the belt. m e base of each
cleat 24' h2s a trans~erse ~ ncion T which is less than the
transverse dicEnsion S of the belt 11' or 12'. The sides 25' of
. each drivè lug 24' converge in a direction away from the bottom
surface 19' of the belt 11' or 12'.
Each belt 11, 12, 11' or 12' is of reinforced elastomeric
r~te-ial 2nd includes a fleYible reinforced structure 22, 22'
n~ a top s~rface 18, 18' and a botto~ surface 19, 19' located
inter e~iate the crop gathering cleats 20, 20' and the driving lugs
24, 24'. The structure 22, 22' has one or more longitudinally
exter.di~g ~i ~h elastic ~dulus cords 23 e~edded therein; the
longitufL~ally e~.enoing center plane of the cords defining the
pitch l~r.e of the belt. A layer 27 of light~æight woven or knitted
f2bric ~ay be positioned adjacent the top surface 18, 18' and
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bottom surface 19, 19' of the belt structure 22, ~2' to provide
increased durability of the belt 11, 12, 11' or 12'.
Referring now to Figures 1, 3, 4 and 5 therein is shown a
dri~e sprocket 30 according to the invention, both individually and
in conjunction with the belt 11, 12, 11' or 12' of the invention
and the gathering head 10 of the invention. Each driving sprocket
3G has a first side 31 and a seeond side 32 as shown in Figure 5
and includes a plurality of equally spaced apart radially
projecting teeth 33 (best seen in Figures 1 and 4 for engagement
with the drivIng lugs 24, 24' of the belt 11, 12, 11' or 12').
Each sprocket tooth 33 is separated from the next adjacent sprocket
tooth 33 by a cavity 34 that is open only to one side of the
(~ sprocket 30. ~eferring now to Figure 4 it is sPen ~hat the
numbers 60 and 61 have be~een them a cavity 34 that is open only
to the first side of the sprocket ~ereas the nu~bers 62 and 63
have between them a cavity 34 that is open only to the second side
32 of the sprocket. The sprocket 30 inclll~Ps a plurality of flange
portions 35 located on alternating sides of the sprocket. Each
flange por~ion 35 is of the same radial projection as that of the
pair of adjacent tee~h between ~hich that flange portion extends.
Each flange portion 35 projects generally radially ~utwardly
perpendicularly to the axis of rotation 36 of the sprocket 30.
Tbus the ccmbination of the alternating flange portions 35 and
, driving teeth 33 wQth the lugs of 24, 24' of the belt 11, 12, 11'
or 12' positively transmit power to the belt and keep the belt from
nrnnLng in a direction parallel to the sprocke~ axis 36 and out of
engageFent with the driving teeth 33. In a preferred e~bod~ment .
the teeth 33 of the driving sprocket 30 are of a radial dilension D
that is considerably greater than the 2mount H which a driving lug
24, 24' projects perpendicularly from the bottom surface 19, 19' of
the belt 11, 12, 11' or 12'. This considerable clearance between
the tips 28 of the driving lugs 24, 24' and the bottoms 37 of the
cavities 34 is provided to inhibit disengagement of the belt 11,
12, 11' or 12' through entrainment and entrapment of the crop or
debris such as ~d, ice and rocks ~ich cay be encountered ~nder
3 49~5
--6~
certain h2rvesting conditions, for ex2~ple, when the crop has
fallen over and is not standing upright at the time of harvest.
Because each cavity 34 is open to a side of the drive sprocket 30
an~ m2terial which would othe~ise be entrained in the bottom 37 of
the cavity 34 is free to exit to the side. Preferably the bottom
surface 37 of each sprocket cavity 34 slopes toward the axis of
rotation 36 of the sprocket 33 in a direction away from the
respective flange portio~ 35 to facilitate self-cleaning of the
sprocket. It is preferable that the radially projecting flange
portion 35 be connected to the cavity bot~om suIface 37 by an
arcuate surface 38 to facilitate self cleaning. The fore and aft
surface~ 39, 40 respectively of the cavity 34 should join to the
~- bottom surface 37 of the cavity via arcuate surfaces or the bottom
su face 37 of the cavity 34 should itself be an arcuate surface as
shown. ~n the accocpanying drawnng the bottom surfaces 37 are
sh~n to be conical. I~en these curved surfaces are combined as
described and shown in Figures 4 and 5 the engagement of the
driving lugs 24, 24' of the belt 11, 12, 11' or 12' with its
associated sp ocket 30 serves to push dow~ardly and ou~wardly any
debr~s that ~ay otherwise become entrapped in the drive sprocket
30.
Refer~g nuw to Figures 6 &nd 7 as well as Figure 1 there is
shown a sheave 50 or idler pulley aCcor~ing to the invention. m e
~^; sheave in~ludes a cylindrical hub 51. A pair of axially spaced
flanges 52, 53 project ra~ ly from the hub 51. The inner side
surfaces 54 of the flanges 52, 53 converge in a direction toward
the axis of rotAtion 55 of the sheave 50 forming a
circ~r~ferenti211y e~ end;r~ groove 58 between them. Each of the
flz~.ces 52, 53 is interrupted in the circu~ferential direction of
the sh~ve 50. The interrupticns of one of the flanges 52 are not
aligr.Pd ~ th the ~nte~ruptions of the other 53. As shown in Figure
7 th~ height H of each drive lug 24' corresponds to the radial
projecticn of the flanges 52 and 53. Thus in the belt and sheave
co~birætlon as the belt 11, 12, 11' or 12' engages the sheave 30
the tips 28 of the drive lugs 24' contact the outer cylindrical
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surface 56 of the hub 51 and the edge portions 29 of the belt
structure 22 contact the radially outermost suxfaces 57 of the
flanges 52, 53. Th~ flanges 52, 53 of the sheave 50 are axially
spaced apart so that the drive lugs 24' do not wedge between
the ~langes 52, 53 as in a conventional V-belt and pulley system.
The flanges 52, 53 serve to guide ~he belt. The flanges 52, 53 are
not intended to transmit power frGm the belt 11, 12, 11' or 12'
to the sheave 50. Because the flanges 52, 53 ~re interr ~ ted in the
circumferential direction of the sheave 50 foreign material that
might otherwise become entrapped in the bottom of the
circumferential groove 58 of the sheave 50 is able to exit to the
sides 59, 64 of the sheave 50. In a preferred e~odiment the
circumferential distance between the interruptions of each flznge
52, 53 of the sheave 50 is not an integral ~lltiple of the driving
lug pitch B so as to ensure that all portions of the sheave 50
eventually contact the longitudinal sides 25 of the driv ~ lugs 24
~nd thereby even out wear of the belts 11 or 12 and associated
sheave 50. The interruptions of one flange 52 are not aligned ~
the interruptions of the other flange 53 so as ~o assure g~iding
. 20 and control of the belt 11 or 12 at all times. The interruption of
the fla~ges need not be of the sa~e circumferential extent sh~wn to
be effective. The particular e~bod~ment shown facilitates lding
of the sheave.
: The main reinforcing cords 23 of the belt 11 or 12 are of high
tensile dulus material. Fiberglass or ar~n;d are p~ef~rred for
cords 23 although it is-believed that nylon? polyester or the like
may also be employed. High tensile loading of the belt 11, 12, 11'
or 12' can occur at those times ~hen an e æ of corn or a staIk
becomcs lodged in the machine.
The driving lugs 24, 24' of the belt 11, 12, 11' or 12' of the
preferred e~odiment described and sh~n hereIn are of truncated
pyramidal configuration and are not involute or conjugate. The
sprocket 50 as shcwn is of a design that facilitates entry and exit
of the driving lugs 24, 24' of the belt 11, 12, ll' or 12' by
3~ provid m g clearance for the co m ers 43 and tip 28 of each driving
l~ ltS
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lug 24, 24'. Belts have been ~ade utilizing elastc~er ~aterial that
is a blend of natural r~bber and synthetic isoprene blended.
Hswever it is believed that other elastom~ric or resilient
materials for exar,ple, chloroprene or polyurethane or the like
would serve equally well.
Referring to Figure 1 it is seen that the leading edge 42 of
each cleat 24 o the belt 11 or 12 is preferably tapered. The
tapered leading edges 42 of each pair of opposed cleats thus tend
to force the dislodged ears of corn toward the fore and aft
directed centerline of the gathering head 10 and facilitate
withdrawal of each cleat 20 from the ear~s) of corn that it is
conveying as the cleat begins to rotate around its associated drive
` sprocket 30 at the aft end 17 of the gathering head 10. Ihe
triangular configuration of the cleats 20' of belt 11 or 12'
provide tapered leading edges to sicilarly facilitate withdrawal of
e2ch cleat 20' from the ears of corn.
The sprockets 30 and sheaves 50 are preferably made of ultra
hign molecular weight polye-,hylene. This material possesses
sufficient st-&ng-.h and rigidity for this ~pplication. Use of this
~terial is aavcntageous because it is not subject to rusting or
corrosicn ard its low coe!f cient of friction aids in the desired
self-cle2n~ng action. Of course, plastics including reinforced
plas~ics or metals may be used in construction of the sprockets and
sheaves. I-~hen ultra high ~olecular weight polyethylene is used,
each sprocket or sheave preferably includes a metal insert 39 or 59
co~centrically positicned in its hub.
The cleats 20 are shown ;~ Figure 1 .o be aligned with one
~-.o,he- is is not required. The cleats 20 ~ay be staggered
relative to cne another.
It is to be u~derstood that the relative positions of the
c~ g sprockets and idler sheaves could be reversed such that the
driving sproc'~ets would be located at the for~^~ard end 16 of the
~ac,~ne .h2t first engages the crop.
'~nile certain representative e~bodi~ent and its details hav~
been described for the purpose of illustrating ,he ~nvention it
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ill be apparent to those skilled in the art that various ch2nges
and difica~ions m2y be ~ade therein without departing fron the
spirit or scope of the in~ention.
~,......
