Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BACKGROUND OF THE INVENTTON
Field: The invention is in the field of conveyors used in the
handling of articles subject to bruising, especially articles of agricultural
produce, and is particularly concerned with improvements tending to mini-
mize if not entirely eliminate bruising of the articles being handled.
State of the Art: Endless draper chains are commonly used
on conveying apparatus constructed for the handling of various articles,
especially items of agricultural produce such as potatoes, beets, carrots,
onions, etc. In instances of inclined conveyors for elevating or lowering
such produce as, for example9 during harvesting, sorting, packaging, and
storage operations, upstanding, article-retaining members are often
provided on at least some of the links thereof. In instances of belt type
conveyors utilizing continuous belts instead of chain links, similar up-
standing, article-retaining members are also often employed. In loading
such a conveyor or transferring articles from one run thereof to another,
the articles to be conveyed commonly fall onto the working conveyor face -
with considerable force. If such articles are susceptible to bruising, as
are items of agricultural produce, considerable damage is done when they
strike the upstanding, article-retaining members, as they often do.
Accordingly, it is common practice to mold such article-retaining members, ~.
20 whether they be upstanding fingers, paddles, or some other formation, from
an elastomeric material, such as rubber~ without stiff reinforcing cores.
Examples of this practice are found in U. S. Patent Nos. 2,149, 776;
2,177, 730; 2, 244, 827; 2, 769, 539 and 3, 679, 050, where it is shown to be
old to mold such article-retaining members integrally with elastomer
coatings on the chain links or with elastomer belt surfaces. ;
A significant shor~coming of such practice, however, has
resulted from the need to maintain article-retaining stiffness in such
members. Undesirable bruising still occurs.
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Objective: A principal objective of this invention was to
develop a reliable chain or belt conveyor having one or more article-retain-
ing members of elastomeric material upstanding from the working face of
the conveyor chain or belt, wherein the upstanding members provide support
5 for transport of articles, especially articles of agricultural produce, on
the conveyor, but will significantly minimize if not completely eliminate
bruising of articles which fall onto them.
SUMMARY OF THE I~VENTION
In accordance with the invention, the foregoing objective was
10 achieved by providing an endless conveyor, usually a chain or belt conveyor,
in which any article-retaining member upstanding from its working face has
a soft cushioning crown of elastomeric material. The cushioning c~own is
sof~ relative to the stiffness required of the article-retaining stem portion
of the article-retaining member9 whether such member is made entirely
of an elastomeric material or of an elastomer-coated pin, paddle, or the ~ -
like of relatively rigid material. Its durometer reading is of non-bruising
softness relative to the comparatively stiff durometer reading of the
elastomeric material constituting the article-retaining member.
In the instance of a draper conveyor chain, the invention
20 comprehends individual chain links therefor, which are often sold singly
as a replacement part or in multiple but unassembled so the purchaser can
fabricate his own conveyor chain.
For handling potatoes and the like, the cushioning crown of
each article-retaining member preferably has a durometer Shore A reading
25 of between about 10 and 25 points hardness, whereas the supporting stem
portion thereof preferably has a durometer Shore A reading about 40 and 70
points shore hardness. ~-
In preferred embodiments of the invention, each article- -;
retaining member is formed from an elastomeric material such as a
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plastisol, whereby the relatively so~t crown thereo~ Gan be
formed integrally with the rela-tively stiff, supporting stem
portion thereof and with the elastomer covering of the chain
link from which it extends.
The improved chain links of this invention can be
used together with conventional links not provided with article-
retaining members in ma~ing a draper conveyor chain having
only a portion of the links provided with article-retaining
members. For example, it has been found advantageous to make
draper conveyor chains wherein alternate links or every third,
fourth~ fith, etc. link is the improved link as described herein.
Conversely, it has also been found advantageous to make draper
conveyor chains wherein aIl the links are of the improved type
of this invention.
A draper conveyor chain having article-retaining links
in accordance with this invention, wherein the article-retaining
members are upstanding fingers spaced apart longitudinally along
the rod members of the respective chain~links, has been fQund
- to be particularly desirable for patato and simila~ dig~ers. -
In accordance with one aspect of the present inve~tion,
there is provided an endless conveyor for articles, such as ;
agricultural produce, which are subject to bruising w~en droppe~ -
thereonto, comprising structure providing an article-receiving
and conveying surface: article-retaining members o elastomeric
material secured to said structure and upstanding from said
surface in mutually spaced relationship sufficient to receive
the articles therebetween, said members having sufficient stif-
ness to retain received articles therebetween when operating
on an incline, and elastomer cushion members crowning the res-
prective article-retaining members, said cushion members being
sufficiently sot to protect articles dropped thereon a~ainst
bruising due to the stiffness of said article-retaining members,
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- the ela~tomeri~ material of the article-retaining members having
a durometer reading in the range of from about 40 to about 70
points Shore A, hardness and the elastomer cushioning members
having a durometer reading in the range of from about 10 to
about 25 points Shore A, hardness.
In accordance with a further aspect of the present
invention, thexe is provided a chain link for draper conveyor
chains used to carry àrticles, such as agricultural produce,
which are subject to bruising when dropped thereonto, comprising
a rigid, elongate rod having linkage members at opposite ends
thereof, and elastomer coating on said rod between said link-
age members; at least one elastomer member having article-
retaining stiffness upstanding from the working face of said
rod between said linkage members and integral with said elasto-
mer coating' and an elastomer cushion member crowning each
such elastomèr member, said cushion member being sufficiently
soft to protect articles dropped thereonto against bruising,-
and wherein the elastomer coating, the elastomer article-re-
taining member,.and the cushion members are molded as a unit
from a plastisol, with the plastisol of the elastomer coatins
and article retaining member being cured to a durometer reading
of from about 40 to about 70 points Shore A hardness, and wit~
the plastisol o the cushion member being cured to a durometer
reading of from about 10 to about 25 points Shore A hardness..
THE DRAWI~GS
Embodiments representing the best mode presently
contemplated for carrying out the invention are shawn in the
accompanying drawings, in which:
. . Fig. 1 is an isomekric view of a fragmentary poxtion
3Q of the length of an endless draper chain conforming to the
invention, in which the article-retaining members are fingers
extending upwardly from the working ~aces.of alternate, in-
dividual, chain links. ~ ~
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Fig. 2, an enlarged ~ragmentary view in si~e elevation
taken from the right of the portion shown in Fig. 1, a potato
being shown striking one of the fingers as it drops onto the
dra~er conveyor from a distance above such conveyor, the view
being enlarged:
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~ig. 3, a vertical section taken along the line 3-3 of ~ig. 1
and drawn to a larger scale;
Fig. 4, a vertical section taken along the line 4-4 of Fig. 3,
parts in the background not being shown;
Fig. 5, a view similar to that of Fig. 3, but illustrating an
embodiment wherein a single elongate paddle prolTides the upstanding
article-retaining member; and
Fig. 6, a view similar to that of Fig. 47 but taken along the
line 6' 6 of Fig. 5.
DEIAILED DESCRIE~ION OF THE ILLUSIRATED EMBODIMENTS
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In accordance with the invention, an improved conveyor is
provided comprising an endless receiving surface having a plurality of
stiff, article-retaining members upstanding from such surface and crowned
with respective, soft, elastomeric, cushion members. The soft cushion
members provide protection against the bruising of articles which are
dropped onto such receiving surface of the conveyor.
In the particular form illustrated in the drawings, the conveyor
is a type commonly known as a "draper chain" conveyor, and is made up
of interengaged individual chain links having one or more article-retaining
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mernbers upstanding from the working surfaces of the chain links or of
selected chain links thereof. However, there are other types of conveyors,
such as continuous endless belt conveyors, to which the invention is
applicable so long as there are article-retaining members upstanding from
the working surfaces thereof.
ln the embodiment of Figs~ 1-4, the draper chain comprises
a series of individual, elongate, chain links 10 and 11 interengaged at their ~ -
respective ends, and extending transversely of the length of the conveyor.
Each OI such links is bent to form from a rigid rod so as to have linkage
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members lOa or lla at respective opposite ends of an intermediate straight
portion lOb or llb, which, with similar parts of other adjacent links, goes
to form an article-receiving surface or bed for the conveyor.
~s is customary in conveyors of this type, the intermediate
rod portions lOb and llb of the respective chain links 10 and 11 have elastomer
coating 12 and 13, which terminate sufficiently short of the linkage members
lOa and lla to provide for effective interengagement of the linkage members
of adjoining chain links and to facilitate chain link engagement by idler
and drive sprocket wheels over which the conveyor chain passes.
Either all or selected ones of the chain links, here the
alternate ones designated 10, are provided with upstanding, article-retain-
ing, elastomer members in the form o~ fingers 14, there being a pl-lrality
of such fingers arranged in mutually spaced relationship along the length
of the coated, intermedia~e rod portion lOb of each chain link 10. It is
normally pre~erred in the art to have such fingers somewha~ flexible, so
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as to yield in providing receiving pockets for items of produce, such as
potatoes, yet stiff enough to hold such items in place on an inclined conveyor.
Also~ it is usual to mold such fingers integrally with the elastomer coating
12, applied to rod portions, lOb, of the chain links, 10.
The invention provides each of the fingers 14 with an anti-
bruising crown 15 of soft, elastomeric material, the durometer reading of
which is significantly less than the durometer reading of the remainder of
the finger, i.e., the stem portion 14a thereof.
Thus, the elastomer coating 12 of ~he rod portion lOb of each
link 10 and the elastomer fingers thereof typically are within a range of
from about 40 to about 70 points Shore A hardness as measured on a
standard durometer instrument. In accordance with the invention, however, - :
the soft, elastomer crowns 15 have a considerably less Shore hardness,
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e. g., within a range of from about 10 to about 25 points, while the remain-
ing or stem portiorls 14a of the fingers 14 have the usual Shore hardness,
e. g., within the range of from about 40 to about 70 points Shore ~.
In accordance with the invention, the soft cushion members
5 15 provide protection against bruising and other damage ~o articles,
especially articles of agricultural produce such as potatoes3 dropped onto
the receiving surface of the conveyor. As indicated in Fig. 2, cushion
members 15 yield as an article such as the potato 16 drops thereonto,
thereby cushioning ~he impac~.
In this embodimen~ of the invention, auxiliary article-
xetaining members in the form of elastomer shoulder members 17 are
advantageously provided adjacent the respective ends of each of the chain
links 10. ~s illustrated, these shoulder members 17 are of flat, paddle-
like formation extending upwardly from the working face of the chain
lS link as do the fingers l~Lo Shoulder members 17 are similar to fingers 14
in that they compxise elastomer stem members 17a, for retaining received
articles on the conveying surface or bed of the conveyor, and so-et cushion-
ing crowns 18 corresponding so far as softness is concerned to the crowns
15 on fingers 14.
If fingers 14 of adjacent chain links 10 are offset with respect
to each other, rather tharl being in line as illustrated, the length of one of
the shoulder members 17 longitudinally of the link will be greater than ~he
other one on that link for each of such links 10 and the placement of such
shoulder members will alternate from link 10 to link 10 cllong the length ;
of the conveyor chain.
In those instances in which chain links 10 are interspersed
with ordinary chain links 11, it may be found advantageous ~o also provide
the links 11 with corresponding shoulder membersJ even though they are
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not shown so in Fig. 1. If so, such shoulder members would also have
cushion crowns as do the illustrated shoulder members 17.
Instead of upstanding fingers and shoulder members, the
links corresponding to lO may have article-retaining members of various
formations. For example, as shown in Figs. 5 and 6, such a correspon-
ding link 20 has a single upstanding paddle member 21 e~tending along
substantially the entire length of the link. ~s in the foregoing instances,
such paddle member 21 is crowned by a soft elastomer cushioning member
22 above the relatively stiff stem portion 21a. Also9 as in the foregoing
instances, such stem portion 21a is a continuation of the elastomer coating
23 of chain link rod 24
In all instances, it is preferred to mold the chain link rod
covering and the upstanding article-retaining member of members and the
soft cushion member or members thereof integrally from an elastomer
such as a plastisol, having due regard for the relative softness and stiff-
ness of the several members in order for them to function effectively.
This is done by differentially compounding polyomylchloride and plasticizer
in known manner to achieve the shore hardnesses desired for the respec-
tive parts of the resulting integral molding.
Whereas this invention is here illustrated and described with
respect to embodiments presently contemplated as the best mode of
carrying out the invention in actual practice, it is to be understood that
various changes may be made w~thîn the scope of the generic teachings
hereof.
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