Bucket conveyor chain

An improved bucket conveyor chain that uses a series of plate type lines 3 connected together at adjacent ends by a bars 5 and 9. Ropes 11 are connected to the bars 5 and 9 to protect the chain from breaking in half in case of damage. The bars 5 and 9 are sectionalized and overlapped thereby providing easier maintenance.

BACKGROUND 
1. Field of Invention 
This invention relates to a composite bucket conveyor comprised of endless 
bands or strands of ropes, belts, or link plates, arranged for high 
performance, safety, and easy maintenance. 
2. Description of Prior Art 
Past bucket conveyor chains can be grouped into two general groups, i.e., 
those in which the buckets are connected to axial tension elements 
comprised of rigid links that are hinged together such as roller chains 
and those in which the buckets are attached to long axial tension elements 
such as rubber belts, leather belts, wire ropes, or metal belts which are 
joined at their ends to form an endless belt. My U.S. Pat. No. 5,469,957 
introduced a third type of conveyor chain comprised of a plurality of 
short link plates that are held together and bent about closely spaced 
bars as the chain is circulated about its pulleys or wheels. This present 
invention improves upon my U.S. Pat. No. 5,469,957. 
OBJECTS AND ADVANTAGES 
Accordingly I claim the following as my objects and advantages of this 
invention: 
To introduce a way to maintain parts of the chain with less disassembly. 
To introduce a way of attaching additional bars to add more buckets and 
enhance smoothness of operation. 
To introduce a much improved bucket conveyor chain comprised of a series of 
link plates by adding ropes, belts, or other axial tension members to 
provide a safety to keep the chain from separating should the link plates 
break in half. 
To introduce a way to reduce damage to the ropes, belts, and link plates as 
they bend back and forth. 
To improve traction of the chain on its wheels or pulleys. 
To introduce a method for reducing chordal action dynamics and stress on 
the ropes, belts, and link plates.

DRAWING REFERENCE NUMERALS 
1 wheel 
3 link plate 
5 bar 
7 bar screws 
9 bottom bar 
11 rope 
13 external bucket plate 
15 bucket screws 
17 bucket 
19 guide 
21 belt 
23 belt splice 
25 rope clamp 
27 bar grooves 
29 protective cover 
DESCRIPTION OF THE INVENTION 
Referring to FIGS. 1, 2 and 3 the chain is comprised of a plural series of 
link plates 3 located side by side. Link plates are comprised of materials 
that have a modulus of elasticity (E) greater than 1,000,000 pounds per 
square inch. They can be made of composite materials that have an 
aggregate E greater than 1,000,000 pounds per square inch. Link plates are 
also square or rectangular in cross section. The edges of link plates can 
have rounded edges and corners if desirable. The ends of adjoining link 
plates 3 are overlapped and held in position by clamping them in-between a 
pair of top bars 5 and a bottom bar 9 The clamping force is provided by 
bar screws 7 which mount in holes match drilled in the link plates 3 and 
bars 5 and 9. These screws are countersunk in bars 5 and 9 to prevent them 
from damaging the wheels 1. 
Referring to FIGS. 1 and 2, ropes 11 comprised of any material including 
wire are passed through the buckets the entire length of the chain. Ropes 
11 are also passed through the bars 5 and 9. Ropes are also passed through 
the guides 19. The ropes 11 are added to prevent the bucket chain from 
breaking in half should the link plates 3, bars 5 and 9, or the bar screws 
7 fail. There are two top bars 5 instead of one because this allows 
partial disassembly of the chain to work on one of the series of link 
plates or to remove a rope from in-between the bars 5 and 9 without 
breaking the chain in half as would be the case if bar 5 was comprised of 
one part. 
Referring to FIGS. 9 and 10 the ropes of FIGS. 1 and 2 can be placed side 
by side when clamped together with the bars 5 and 9 to form and endless 
loop. Additional rope clamps 25 are used to assure that they do not pull 
apart. The insides of the bars 5 and 9 are shaped to accept the shape of 
the rope 11. 
Referring to FIGS. 1 and 2, buckets 17 are attached to the ends of bars 5 
and 9 by bucket screws 15 which protrude through holes drilled in bucket 
17, and external bucket plate 13. External buckets plate 13 is used to 
distribute the compressive stresses created by the clamping force of the 
bucket screws 15 upon the shell of bucket 17. The sides of the bucket 17 
and/or the external plate 13 can be used to guide the chain together with 
or without the use of additional guides. The external 13 bucket plates can 
be used to mount other accessories. Guides 19 are positioned adjacent to 
the sides of wheel 1 in order to prevent the chain from coming off of the 
wheel. Wheel 1 supports the guides the chain as it circulates about and 
conveys material. 
The distance that the bars 5 and 9 are spaced along the chain are important 
because of chordal action dynamics. Chordal action is the rise and fall of 
the chain as it goes around a wheel 1. It is caused by the protrusion of 
the bars 5 and 9 which makes the mating surface between the wheel 1 and 
the bars 5 and 9 of the chain discontinuous and uneven resulting in a 
bumpy and jerky engagement. Chordal action is directly related to the 
spacing of bars 5 and 9 along the length of the chain. It has been found 
that if the bars are spaced less than 5 inches apart along the chain that 
chordal action can be controlled to within acceptable limits with less 
stress on the leaf plates, ropes, or other elements of the conveyor chain. 
Referring to FIGS. 1, 3, and 6 additional bars 5 and 9 can be spaced 
closer together without increasing the number of link plates by drilling 
additional holes in the link plates in-between the two ends and adding 
additional bars 5 and 9 accordingly. Referring to FIGS. 1 and 4, and 
alternate way of mounting bars 5 and 9 can be accomplished by positioning 
the bar screws 7 laterally to the side of link plates 3 so that additional 
bars 5 and 9 can be added without passing the bar screws 7 through the 
link plates 3, this makes infinite adjustment of the spacing between 
adjacent sets of bars 5 and 9 possible. 
Referring to FIGS. 4 and 10, the inside surfaces of bars 5 and 9 can be 
shaped to match the shape of the ropes 11 or the link plates 3. Referring 
to FIG. 5 the bars 5 and 9 have a curved surface at the corners where the 
ropes or link plates protrude from the bars 5 and 9. This reduces stresses 
that would cause the rope 11 or link plates 3 from being damaged as they 
bend around the wheel 1. 
Referring to FIGS. 6 and 11 a protective covering 29 made of a flexible 
material such as rubber, paint, or plastic can be attached to the exposed 
surfaces (topes, bottoms, and edges) of link plates 3 in the areas where 
link plates are not in contact with bars 5. Referring to FIG. 11, the 
protective covering 29 can also be applied to the link plates 3 where it 
passes through the bars 5 and 9 and is sandwiched between the two bars 5 
and 9 when they are clamped together by the bars crews 7. The protective 
cover 29 can also be applied to the surfaces of bars 5 and 9 to totally 
encapsulate the chain. 
Referring to FIGS. 1 and 2, the ends of bars 5 and 9 extend out past the 
edges of link plates 3 and cables 11 to provide a standoff for mounting 
buckets 17 or external bucket plates 13. This prevents the buckets 17 or 
external bucket plates 13 from contacting the edges of link plates 3 and 
rope 11. 
Referring to FIGS. 7 and 8 the ropes 11 of FIGS. 1 and 2 could be replaced 
with belts 21 made of natural or synthetic fibers or elastomers. All of 
the improvements above pertaining to ropes pertain also to belts. The 
belts are overlapped and clamped between the bars 5 and 9. Additional belt 
clamps 23 are added as required between the bars 5 and 9 to assure that 
they do not pull apart. Where the belts 21 pass through the buckets they 
can be clamped by conventional belt clamps anywhere along their lengths. 
Referring to FIGS. 12 and 13 grooves are cut in the bars 5 and 9 on the 
surface that comes in contact with wheels 1. This increases friction and 
reduces slippage as the conveyor chain goes around its wheels. 
OPERATION OF THE INVENTION 
Referring to FIG. 2, wheel 1 is turned by a suitable power source. Friction 
between the wheel 1 and the bars 5 and 9 provides a tractive force to 
propel the chain. As the chain circulates around the wheel 1, the link 
plates 3 bend allowing the chain to go around the wheel 1. The link plates 
3 are ideally suited to repeated bending in the area where they protrude 
from the bars 5 and 9 without kinking, cutting, graying, etc. as do ropes 
and belts. The link plates 3 are the primary members carrying the load and 
stress imparted to the conveyor chain. The ropes and belts are added as 
secondary members to serve as a safety to prevent the chain from breaking 
in half should the link plates 3, bars 5 and 9, bar screws 7, etc. fail. 
The ropes 11 that run through the buckets 17 pass loosely through holes 
drilled in the buckets and will keep the chain on path should it break in 
half. The ropes 11 that run through the guides 19 pass loosely through 
holes drilled in the guides 19 and will keep the chain on path should it 
break in half. Passing the ropes 11 loosely through the buckets 17 and 
guides 19 prevent bending stresses in the rope that would cause it to wear 
out quickly. 
Referring to FIGS. 1 and 2, ropes 11 are also passed through the bars 5 and 
9. While ropes are good tension elements they tend to wear out prematurely 
when bent around discontinuous members such as the edges of the bars 5 and 
9. This amount of wear is a function of the load they are under when bent. 
Therefore in order to prevent wear a small slack in introduced into the 
ropes 11 at assembly so their length between adjacent pairs of bars 5 and 
9 is longer than the corresponding link plates 3. The ropes 11 should also 
be made long enough so that when the conveyor chain goes around the wheel 
1 the ropes 11 do not take any significant part of the load. Therefore the 
link plates of the chain 3 take the load and the ropes 11 are only 
slightly stressed as they go around the wheel in a standby mode thereby 
greatly increasing their life. Another advantage of making the ropes 
longer than the link plates 3 is that should they 11 take the load due to 
damage of the link plates 3 the chain will run less smooth due to the 
increase in spacing of the bars and the resulting increased chordal 
action, this change in smooth action can be monitored and used to warn of 
damage to the link plates 3. 
Referring to FIGS. 1 and 2, driving the bar 5 into two parts makes 
maintenance on the topes 11 and the link plates 3 easier since a damaged 
element can be replaced with less disassembly. 
Should the link plates 3 fail and the topes 11 take the load or if a short 
lived chain is required where the link plates 3 are not used the life of 
the ropes 11 can be increased by spacing the bars 5 and 9 in close 
proximity along the length of the ropes. This reduces the amount of 
bending across the corners of bars 5 and 9. Bending can be further reduced 
by curving the edges as shown in FIG. 5. 
RAMIFICATIONS AND SCOPE 
Although the description above contains many specificities, these should 
not be construed as limiting the scope of the invention but as merely 
providing illustrations of some of the presently preferred embodiments of 
this invention. For example: 
Every now and then a set of bats 5 and 9 could be left off down the length 
of the conveyor chain. This extra spacing would cause a bump every now and 
then as the chain circulates about the wheels. A bump every now and then 
may not cause detrimental effects. 
Other appendages could be added to the bars 5 and 9 to perform a variety of 
functions such as plowing, sweeping, etc. 
A variety of different types of clamps could be used to mount to the bars 5 
and/or 9 to hold the ropes, belts, and link plates. 
The ropes, belts, could be made up in short segments to facilitate 
replacing specific damaged areas. 
The inside of the bars 5 and 9 can be shaped to match the tension elements 
held. 
The position of the ropes, belts, and link plates could be staggered in 
their side by side orientation. 
Both the top and bottom bars 5 and 9 could be several pieces and overlapped 
together to aid in chain assembly and repair. 
The curved surface adjacent to the ropes and belts in the bars 5 and 9 as 
shown in FIG. 5 could be formed as a surface of revolution. 
The belts and ropes can be replaced with other axial tension members such 
as roller or hoisting chains. 
Belts, ropes, and chains can be short sections starting and ending at each 
bar 5 and 9 or they can span across several bars before being attached. 
Auxiliary splicing means can be used to splice the belts, ropes, and 
chains, in addition to the bars 5 and 9. 
The link plates can be overlapped. 
Other appendages could be added to the bars to attach axial tension 
elements. 
Different groove patterns can be cut in the bars or wheels for enhanced 
traction. 
Thus the scope of the invention should be determined by the appended claims 
and their legal equivalents, rather than by the examples given.