A longitudinally elongate conveyor belt is adapted for conveying a plurality of transversely spaced items. The belt comprises a plurality of interconnected, generally transversely extending rod members which are spaced apart along the longitudinal direction. Each rod member is upwardly arched to define first and second item-supporting segments. The first and second segments diverge in the downward direction so as to resist a tendency for the first and second items to be displaced by belt sag. An outer edge of the belt may be elevated relative to the inner edge to compensate for centrifugal forces.

BACKGROUND AND OBJECTS OF THE INVENTION 
The present invention relates generally to conveyor systems. More 
specifically, the present invention relates to a rod or grid-type conveyor 
belt. 
Rod or grid-type conveyors comprise a series of longitudinally spaced, 
transversely extending rods which are interconnected at their ends as 
exemplified by commonly owned U.S. Pat. No. 4,036,352 issued to White on 
July 19, 1977. Endless conveyors of this type are used for the 
transportation of many goods or products, such as for cooling and proofing 
bakery goods, for example. The conveyor can be arranged in a double helix 
configuration in which the items travel upwardly along an outer helical 
flight and then downwardly along an inner helical flight, as disclosed in 
the above-mentioned White patent. 
Rod-type conveyor belts are particularly useful in operations which utilize 
the circulation of air around the conveyed items, such as in the cooling 
of hot bakery goods, with the items being arranged side-by-side on the 
belt. However, such belts tend to sag under the weight of the conveyed 
items, which can result in a transverse sliding of the items. That is, 
when two items, such as two loaves of bread are disposed side-by-side on 
the belt, both loaves may have a tendency to converge towards the center 
of the belt as the belt sags. Such displacement can be undesirable in 
numerous respects. For example, certain items may become damaged upon 
being turned over or upon making contact with another item. Also, 
displacement of the items may interfere with the proper removal of the 
items. For example, a transfer system may be associated with the conveyor 
which removes one of the side-by-side items while re-cycling the other 
item. That is, the conveyor system may be such that the items on one side 
of the belt achieve a longer residence time in the conveyor system and are 
ready for removal while the items on the other side are to make another 
pass through the system. In that case, proper guidance of the items is 
made difficult if both items have shifted appreciably in the transverse 
direction. Heretofore, it has been necessary to provide a mechanism which 
senses the position of the items and attempts to displace one or both of 
the items back to a more suitable relationship, such as by a blast of air 
for example. 
Another factor tending to displace the items on the belt is the effect of 
centrifugal forces created as the belt travels along a curved path. 
It is one object of the present invention to overcome the above-enumerated 
problems. 
Another object is to provide a rod-type conveyor belt which resists the 
tendency for side-by-side items to shift transversely. 
A further object is to provide a rod-type conveyor belt which resists belt 
sag under the weight of the items being transported. 
It is another object of the present invention to minimize item displacement 
caused by centrifugal forces. 
SUMMARY OF THE INVENTION 
These objects are achieved by the present invention which relates to a 
longitudinally elongate conveyor belt for conveying a plurality of items 
at least some of which are transversely spaced. The belt comprises a 
plurality of interconnected, generally transversely extending rod members 
which are spaced along the longitudinal direction. The rod members are 
generally stiff and each form an upper item-supporting surface. The 
surface is upwardly arched intermediate its ends to define a first 
item-supporting portion for supporting first items, and a second 
item-supporting portion for supporting second items in transversely spaced 
relation to the first items. The first and second surface portions diverge 
in the downward direction so as to resist a tendency for the first and 
second items to be displaced transversely by belt sag. 
Preferably, each of the rod members each upwardly arched to define first 
and second transverse item-supporting segments. 
An outer edge of the conveyor belt may be elevated relative to the inner 
edge to counteract the effects of centrifugal force as the belt traverses 
a curve.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
With reference to FIG. 1, a preferred embodiment of the present invention 
includes a conveyor assembly 10 in which an endless rod-type conveyor belt 
100 includes an outer upwardly moving helical conveyor flight 12 and an 
inner downwardly moving helical conveyor flight 14 which is surrounded by 
the outer flight 12. Thus, an item placed upon the conveyor belt 100 
traverses a double helical path from an inlet portion of the outer flight 
12 to an outlet portion of the inner flight 14. 
In FIG. 2 there is depicted, in top plan view, a skeletal framework for the 
belt 100, but with the belt 100 removed. Thus, the inlet area 17 for the 
outer flight and the outlet area 19 of the inner belt are clearly visible 
therein. 
Double helical path endless conveyors are especially useful for 
transporting items which require an extended residence period on the 
conveyor, such as in the proofing and cooling of bakery goods. Of course, 
other types of items can be conveyed as well. 
With reference again to FIG. 2, the skeletal framework 20 comprises a 
sufficiently rigid structure to support the conveyor belt. A plurality of 
conventional take-up weights 24 may be provided on the frame members 20 to 
tension the conveyor belt 100. A caged ladder 26 leading to a platform 
(not illustrated) may be installed inwardly of the frame members 20 to 
provide an observation area along the upper surface of the conveyor 
assembly 10. 
The conveyor belt 100 may be driven in any conventional manner such as by 
means of a drive mechanism similar to that disclosed in the 
afore-mentioned U.S. Pat. No. 4,036,352 to White, the disclosure of which 
is incorporated herein by reference. Powering the conveyor drive mechanism 
is a suitable motor 30 which may have a variable speed drive. 
A spray head 32 may be provided to clean debris such as food particles from 
the conveyor belt 100 after the items have been unloaded. A catch tank 35 
is provided underneath the spray head 32 to receive the high pressure 
water and chemicals that are sprayed on the belt to clean the belt. This 
spraying process is done in the lower transition portion of the conveyor 
assembly 10 after the items such as baked goods have been unloaded from 
the conveyor belt 100. 
The conveyor assembly 10 is especially useful in the conveying of items in 
side-by-side relationship, i.e., items which are transversely spaced on 
the belt, whether transversely aligned or not, such as the loaves of bread 
IL, OL depicted in FIGS. 1 and 3. 
In order to remove and introduce the loaves relative to the conveyor belt 
100, there is provided a transfer conveyor assembly 36. In FIG. 2, this 
transfer conveyor assembly is depicted in its proper orientation with the 
skeletal framework. Although the conveyor belt 100 is not depicted in FIG. 
2, reference indicia IS, OS, IS', OS' have been inserted therein to 
indicate the location of various sections of the conveyor belt once 
installed as will be explained below. 
The transfer conveyor assembly includes a first conveyor 42 upon which are 
transported the loaves that are to begin residence time on the conveyor 
assembly. This first conveyor 42 terminates at the inner side IS of the 
outer flight 12. 
A second conveyor 38 communicates one side (e.g., an inner side IS') of the 
inner flight 14 with one side (e.g., an outer side OS) of the outer flight 
12. A third conveyor 40 communicates with the other side (e.g., the outer 
side OS') of the inner flight 14 in order to remove from the outer side 
OS' of the inner flight 14 the loaves which have completed their residence 
time in the conveyor assembly. 
Thus, a given loaf to be conveyed is (i) introduced via the first conveyor 
42 onto the inner side IS of the outer flight 12, (ii) conveyed upwardly 
along the inner side IS of the outer flight 12 and then downwardly upon 
the inner side IS' of the inner flight 14, (iii) transferred via the 
second conveyor 38 to the outer side OS of the outer flight, (iv) conveyed 
upwardly along such outer side OS and then downwardly along the outer side 
OS' of the inner flight, and (v) removed from the latter by the third 
conveyor 40 and taken to another processing station. 
The double helix conveyor assembly as described thusfar, including the 
transfer conveyor assembly 36, is conventional. As explained earlier, 
however, the rods 108 of the belt 100 may tend to sag under the weight of 
the loaves or other items being conveyed, as depicted in phantom lines in 
FIG. 3. In this regard, the conventional rod-type belt 100 (FIG. 3) 
comprises a plurality of stiff transverse rods 108, each rod being formed 
with first and second end links 112, 114 at the respective ends thereof. 
The first end links 112 of successive rods are interconnected, as are the 
second end links, to form the continuous belt 100. Heretofore, the rods 
108 have comprised straight members upon which the side-by-side loaves OL, 
IL rested. As the rods tended to sag under the load, the loaves tended to 
converge toward the center of the sag. Such convergence could cause damage 
to the loaves and/or complicate efforts to deposit the loaves onto 
different conveyors at the outlet 19 of the inner flight 14. 
In accordance with the present invention, each of the transverse rods 110 
is bent upwardly at its middle to produce a cambered or arched upper 
surface S as depicted in FIGS. 4 and 5. The cambered rod thus defines two 
discrete item-support segments 116, 118 which, in turn, define discrete 
item supporting surfaces S', S". The item support segments 116, 118 
correspond respectively to the outer and inner sides of the inner and 
outer flights 12, 14. In FIG. 5, the first conveyor 42 is depicted as it 
delivers freshly baked loades to the inner segments 118 of the rods 110 of 
the outer flight 12, and the second conveyor 38 is depicted as it 
transfers partially cooled loaves (taken from the inner side IS' of the 
inner flight 14) to the outer segments 116 of the rods 110 of the outer 
flight 12. 
With reference now again to FIG. 4, the first and second item-supporting 
segments 116, 118 are distinctly angled with respect to each other and 
also with respect to the horizontal. That is to say, the rod 110 is 
cambered to a particular angle (alpha) with both item-support segments 
lying at the same angle to the horizontal. Of course, it would also be 
possible to orient the two item-support segments at different angles to 
the horizontal if so desired. 
The camber produced in the rods is to be sufficient to compensate for 
sagging of the rods under loading, to the extent necessary to prevent the 
loaves or other items from converging to any appreciable degree. 
Preferably, each rod is at least 24-inches in length and has a central rise 
of from 1/4 to 3/4-inches to form a camber angle of from approximately 0.8 
to 3.6 degrees. 
In one preferred embodiment, a rod 110 was formed with a 36-inch length and 
3/8-inch rise at the center of the rod. This provides a camber angle 
(i.e., an angle to the horizontal) of approximately 1.2 degrees. The rod 
camber may be greater or less, as deemed necessary. 
With a plurality of cambered 36-inch long rods 110, two loaves of bread OL, 
IL may be placed transversely side-by-side on the two item-supporting 
segments 116, 118 of the rods 110 (see FIG. 4). The weight of the loaves 
will remove some of the camber from the rods 110. Preferably, however, 
some of the camber will still remain even when the belt is under loading. 
In addition to cambering the rods 110, it is also possible, in accordance 
with the present invention to raise the outside edge 120 of the belt 
relative to the inside edge 122, as depicted in FIG. 6, so that the belt 
is tilted inwardly towards its center of rotation in the helical path. 
Such a tilting is useful to compensate for centrifugal forces acting on 
the loaves which may tend to displace both loaves towards the outside of 
the conveyor belt 100. The raising of the outer edge 120 of the belt can 
be achieved by adjusting the support rails 44 on which the outside edge of 
the conveyor belt 100 travels. Generally speaking, the raising of the 
outer edge 120 of the belt would be useful only in cases where the belt 
speed is high enough to generate sufficient centrifugal force to displace 
the loaves or other items by an appreciable amount. 
It will be appreciated that the conveyor belt according to the present 
invention greatly minimizes the chances for damage or malfunctions to 
occur in cases where items are being conveyed in transversley spaced 
relationship. That is, by cambering the rods of the conveyor belt, any 
tendency for the rods to sag under the weight of the items is compensated 
for. Therefore, the items will not tend to converge toward the center of 
the belt. In cases where the transversely spaced items are to be 
segregated at a conveyor discharge zone, then, the items will remain in 
proper transversely spaced relationship to facilitate such segregation. In 
cases where the transversely spaced items are also transversely aligned, 
the items will not come into contact at the center of the belt. This is 
especially important when the items are of the type which could become 
damaged if coming into mutual contact. 
The elevating of one edge of the belt relative to the other side further 
militates against transverse displacement of the items as induced by 
centrifugal forces when the conveyor belt traverses a curve. 
Although the present invention has been described in connection with the 
preferred embodiments thereof, it will be appreciated by those skilled in 
the art that modifications, substitutions, deletions, and additions may be 
made without departing from the spirit and scope of the invention as 
defined in the appended claims.