Note: Descriptions are shown in the official language in which they were submitted.
The present lnvention rela~es to buckets ~or hoist
conveyors .
These devices enable the raising at a given linear speed
of fractional loads determined by the unit content or useful load
of the bucket and the number of these buckets per linear meter.
In the case of dry granular substances a part of the load is
pressed back by the reaction of the bottom of each bucket on
sudden contact with the substance to be taken up. Where moist
substances are concerned clogging of the bucket caused by the
sharp angles of the bottom is rapidly observed further reducing
their useful capacity. Currently used buckets for the
transportation of flours or powdery substances generally are
equipped with bottoms of rounded shapes for the purpose of avoiding
clogging. However, this arrangement must be associated with a
reduced linear speed in order to permit the removal of air
accumulated at the moment of the entry of the bucket into the
mass of the substance in the loading phase. The production of
maximum delivery rate at reduced linear speed can only be effected
by over-sized buckets. In order to alleviate these drawbacks,
the invention provides, in one aspect, a bottomless bucket adapted
for use with vertical conveyors for transporting granular,
farinaceous, pulverulent, fluidized and like materials comprising
a generally truncated pyramid body defined by a front wall, a
rear wall and a pair of opposite spaced side walls, the walls of
said body having upper and lower terminal edge portions, a major
portion of said front and side walls each being of a first pre-
determined angle to a plane taken through said upper terminal
edge portions, upper wall portions of said front and side walls
between the terminal edge portions thereof and said major portion
being each of a second predetermined angle to a plane taken
through said upp~r terminal edge portions which is greater than
, said first predetermined angle, and a portion of said rear wall
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upper terminal edge portion being below said front and side
wall upper terminal edge portions thereby forming a cut-out
enabling the positioning pitch of the bucket to be varied
according to the natural slippage bank of the material to be
transported.
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The device3 accor~ing to the invention, enables
the polyvalence of the bottomless buckets to be improved
and universal vertical transportion to be achieved with
granular materials of large caliber such as corn, soya beans,
gravels9 of average and small caliber such as cereals,
chippings, sand, etc.... as well as farinaceous products
such as wheat flours3 cattle feed, oil cakes, slightly
flowing or fluidizing powder products such as powdered
mulk, granulated sugar, very fine flours, plaster or the
like as well as very flowable or ~ery fluidizing materials
such as fine plaster, cement, phosphates and derivatives.
The buckets used for producing hoist conveyor
devices according to the invention comprise at their
upper and lower edges reinforcing means for the purpose
of improving the rigidity of the wall of said buckets,
which walls include laterally a greater convergence so as
eO prevent the largest passage for the lateral feeding
between the walls of the upper bucket and the leading
edge of the following bucket. For the purpose of modifying
the positioning pitch according to the nature of the sub-
stance to be carried, the rear surface of the bucket becoming
supported on the conveyor belt includes at its upper
edge a bevel shoulder whose cutout is of a size to circum-
scribe the contour of the lower part of the bucket placed
~nmediately above.
The accompanying drawings illustrate by way of
example an embodiment of a bucket according to the present
invention~ In the latter :
- Figure 1 shows two consecutive buckets in longitudinal
section along M with, shown in dotted elements9 a possible
B~3
relative position of said buckets in closer pitch position,
- Figure 2 shows the same buckets in cross section along
the line BB~
As shown, the bucket includes at its upper part
- 5 a leading edge l or flanged edge with an outer edge ensuring
rigidity of the bucket and bracing of the upper frame. This
arrangement only involves the front and side surfaces of
the bucket; in the same way these three surfaces are folded
at a certain distance from the upper edge in order to
form a band of rigidity 2. The rear surface 3 is flat so
as to come into application against the conveyor belt on
which each bucket is fixed. The lower edges of the four
walls of the bucket include an edge flanged towards the
inside 4 thus forming a reinforcement of the base of the
bucket. The upper portion of the side walls, comprised
between the leading edge 1 and the fold 2 is slightly
inclined so as to permit good penetration of the bucket
into the material; on the other hand, the part comprised
between the fold 2 and the flanged edge 4 of the bottom
is more converging so as to present the largest possible
passage to the lateral supply between the side walls of
the bucket and the leading edge of the following bucket.
The material to be carried is kept in a column
inside the walls of the buckets to the extent that the
bank formed between each bucket in the zone situated
between the leading edges of the lower bucket and the
trailing edges of the upper bucket, corresponds to the
natural bank of slippage of the material. The angle of
this bank varies according to the nature of the materials,
their degree of humidity, their temperature and their
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tendency to fluidize. The position pitch according to the
material is hence the sum of the total height of the bucket
and the height determined by the intermediate bank or space
between buckets ; ~hus the laying pitch is all the greater
as the natural slippage bank is greater and conversely.
A laying pitch whose value is less than the height of the
bucket nessitates a straggling assembly : this is the case
for fluidizing and very fluidizing materials. To this end,
the rear surface of the bucket includes a cut-out or bevel
shoulder 5, whose height corresponds to the straddling height
with the lower part of the upper bucket. The position pitch
is thus adaptable according as granular, powdery or pulverulent
materials have to be transported ; the me~hod of mounting
can be defined by a given number of buckets to the linear
meter. In the case of transportation of mixed or alternated
materials with the same hoist conveyor device, the selected posi-
tion pitch will be that corresponding to the most dis~
advantageous material. Figures 1 and 2 illustrate in
dotted elements a position pitch with straddling of the
buckets.
The invention applies to all hoist conveyor
devices constituted by belts or chains equipped with
buckets.
