Conveyor construction

A conveyor construction including a frame having a pair of side rails with each side rail having a longitudinal T-shaped slot. A plurality of cross members are connected between the side rails and support a bed plate. An endless belt rides on the bed plate and is trained over an adjustable spindle assembly which is located at an end of the conveyor. The spindle assembly includes a spindle journalled between a pair of side members that are mounted for sliding movement in the T-slots of the respective side rails. A ratchet and pinion mechanism interconnects the conveyor frame with the spindle assembly and acts to move the spindle assembly longitudinally of the frame to tension the belt. A belt tracking mechanism is associated with each side of the spindle assembly and includes a cam member which is engaged with the respective side member of the spindle assembly. Individual rotation of the cam members serve to properly track the belt on the bed plate. To attach components to the conveyor frame, spring loaded nuts are slidably mounted in the T-slots of the side rails and the components are attached to the spring loaded nuts.

BACKGROUND OF THE INVENTION 
U.S. Pat. No. 3,923,148 describes a conveyor construction for conveying 
relatively small parts or articles in which the conveyor belt is trained 
over a pair of spindles or rollers and each spindle is journaled relative 
to the conveyor frame by bearing assemblies which are located within the 
ends of the spindle. As the bearing assemblies are located inboard of the 
side rails of the conveyor, two conveyors can be placed in close 
side-by-side relation. 
There are a number of features which are important in the design of a 
conveyor. One of the features in the ease and quickness of removal of the 
belt for maintenance or replacement. In certain types of conveyors 
utilizing a U-shaped frame, it is necessary to remove the bed plate from 
the frame in order to replace the belt and this is a time consuming task. 
Another desired feature for a conveyor is a precise mechanism for 
tensioning and tracking the conveyor belt. In many conveyors, the belt 
tensioning and tracking mechanisms are combined by journaling the ends of 
the tensioning roll or spindle in slide blocks which are slidable relative 
to the conveyor frame. By individually adjusting the position of the slide 
blocks, the belt tension and tracking can be adjusted. However, in 
mechanisms of this type a tracking adjustment can effect the tensioning, 
and vice versa, so that trained personnel is required in order to properly 
adjust the tension and tracking. 
A further desirable feature for a conveyor is the ability to attach 
components, such as sensors, guides, stops, and the like, to the conveyor 
frame and to be able to position the components at various locations along 
the length of the conveyor. In certain types of conveyors, as used in the 
past, components could only be attached at specific locations along the 
length of the conveyor by utilizing the screws or fasteners which connect 
the bed plate to the side rails, or by drilling specially located holes. 
SUMMARY OF THE INVENTION 
The invention is directed to an improved conveyor construction. The 
conveyor includes a frame having a pair of spaced parallel side rails, 
each being formed with a longitudinal T-shaped slot. The side rails are 
connected together by a plurality of spaced transverse cross members and 
each cross member is provided with an upwardly facing T-shaped slot. A bed 
plate, which supports the upper run of the conveyor belt, is mounted on 
the upper surfaces of the cross members. To secure the bed plate to the 
cross members, a plurality of nuts can be slidably mounted in each slot in 
the cross member and screws extend through openings in the bed plate and 
are threaded with the nuts to secure the bed plate to the cross members. 
The conveyor belt is trained over an adjustable spindle assembly which is 
located at one or both ends of the conveyor frame. The spindle assembly 
includes a spindle or roller that is journaled between a pair of side 
members that are mounted for sliding movement in the respective T-slots of 
the side rails. Tension on the belt is adjusted by a rack and pinion 
mechanism. At least one rack is mounted on the conveyor frame between the 
side rails and extends longitudinally of the frame. An end of the rack is 
engaged with the spindle assembly. A pinion is mounted transversely 
between the side rails and is engaged with the rack. Rotation of the 
pinion will move the rack longitudinally and thereby adjust the position 
of the spindle assembly and control the tension on the conveyor belt. 
The invention also includes a belt tracking mechanism which is separate 
from the belt tensioning mechanism. The belt tracking mechanism includes a 
pair of cam blocks each of which is mounted in one of the T-slots in the 
side rails. Each cam block includes a rotatable cam or eccentric that is 
engaged with the corresponding side member of the spindle assembly. By 
individually rotating each cam, each side member of the spindle assembly 
can be moved longitudinally to thereby skew or track the conveyor belt. 
As a feature of the invention, various components can be attached to the 
conveyor frame through spring loaded nuts or T-nuts which are mounted for 
sliding movement in the T-slots in the side rails. Each nut is formed with 
a generally rectangular inner section and a square outer section. To 
install the nuts, the narrow dimension of the rectangular inner section is 
inserted into the T-shaped slot and the nut is then rotated 90.degree. to 
lock the wider portion of the rectangular inner section in the slot. A 
spring that is positioned between the inner section of the nut and the 
inner wall of the slot urges the outer square section of the nut into the 
stem portion of the T-slot. Various components, such as guides, 
photosensors, stops, and the like can be attached through screws to the 
spring loaded nuts. As the nuts are slidable within the T-slot, the 
location of the components can be positioned as desired. 
Each of the side rails of the conveyor frame is also provided with an upper 
groove and a lower laterally extending rib which are spaced vertically 
from the T-slot in the side rail. A side wiper can be snap-fitted into the 
upper groove and includes an inclined surface which extends inwardly and 
downwardly over the side edge of the conveyor. In addition, clamping 
blocks can be connected to the lower rib in each side rail and serve to 
connect the conveyor frame to a supporting structure or base, or 
alternately, serve to connect auxiliary components, such as a drive 
system, to the conveyor frame. 
In a modified form of the invention, the construction includes a pair of 
spaced parallel conveyors with each conveyor including an outer side rail, 
and a series of cross members extend transversely between the side rails. 
Each conveyor includes an endless conveyor belt and a common drive spindle 
extends transversely between corresponding ends of the conveyors and 
serves to drive the belts. At the opposite ends of the conveyors, the side 
rails project longitudinally beyond the last cross member of the series 
and each conveyor includes an inner side rail section which is disposed in 
parallel spaced relation to the projecting end of the outer side rail. 
A spindle assembly, which includes a rotatable spindle, is mounted for 
sliding movement relative to the projecting end of each conveyor and a 
belt tensioning mechanism and a belt tracking mechanism, similar to that 
employed in the first embodiment, are associated with the projecting end 
of each conveyor to tension the respective conveyor belt and provide 
proper tracking of the belt. 
The invention provides a conveyor in which the belt can be more readily and 
quickly removed for maintenance or replacement. In addition, the conveyor 
can be readily changed in width by substituting cross members of different 
lengths and exchanging drive belt spindles. 
In the invention, the belt tensioning and tracking mechanism are 
individually operated which enables the belt to be more readily tensioned 
and tracked by inexperienced personnel. After the belt has been properly 
tensioned, the tracking mechanism is operated to provide the desired 
tracking of the belt. The cam operated belt tracking mechanism provides an 
infinite adjustment for tracking with minimum interference with the 
tensioning. 
Other objects and advantages will appear in the course of the following 
description.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT 
FIGS. 1 and 2 illustrate a conveyor 1 mounted on a base or supporting 
structure 2 and which has particular use for conveying relative small 
parts or articles. Conveyor 1 includes a frame 3 composed of a pair of 
spaced, parallel side rails 4 which are connected by a plurality of cross 
members 5. A bed plate 6 is mounted on the cross members 5 and supports 
the upper run of an endless conveyor belt 7. Belt 7 is trained over a 
drive spindle 8 located at one end of the conveyor and an idler spindle 9 
mounted on an adjustable spindle assembly located at the opposite end of 
the conveyor. A conventional power source which may take the form of a 
hydraulic or electric motor, not shown, is connected to drive spindle 8 to 
drive belt 7. 
Side rails 4, which can be formed of extruded aluminum, are each provided 
with a longitudinal slot 12 which extends the length of the side rail and 
which is generally T-shaped in cross section. Each slot 12, as seen in 
FIGS. 4, 5, and 8, is bordered by an upper wall 13, a parallel lower wall 
14, and an inner wall 15 which connects walls 13 and 14. In addition, the 
outer portion of slot 12 is bordered by a pair of spaced lips 16 which 
define the stem portion of the T-shaped slot. 
In addition, each side rail 4 is formed with an upwardly extending flange 
17 which extends upwardly beyond the bed plate 6 and a downwardly 
extending flange 18. Flanges 17 and 18 are provided with a longitudinal 
groove 19 and a longitudinal rib or flange 20, respectively, which are 
located on either side of the T-slot 12 and extend the full length of the 
side rail. 
As shown in FIG. 4, a side wiper 22, preferably formed of plastic, is 
connected to the upper flange 17 of each side rail. Wiper 22 includes a 
longitudinal rib 23 which is engaged with groove 19 and the inner portion 
of the wiper is formed with an inclined surface 24 which extends 
downwardly over the side edge of the conveyor belt 7. 
The lower rib 20 in each side rail can be utilized to connect the side 
rails to the supporting structure or base 2 through clamps 25. As 
illustrated in FIG. 4, each clamp 25 includes an outer plate 26 having a 
longitudinal groove 27 having a longitudinal groove that is engaged with 
rib 20. In addition, each clamp 25 has an inner plate 28 which is 
positioned against the inner surface of lower flange 18 of the side rail 
and the lower edge of flange 18 engages a shoulder 29 in the clamping 
plate 28. A bolt 30 connects the plates 26 and 28 to secure the clamp to 
the side rail 4. 
Where the conveyor has a substantial length, the lower run of belt 7 can be 
supported on one or more intermediate idler rollers 31, which are attached 
to clamping plates 28. As shown in FIG. 4, each roller is journalled by 
suitable bearings 31a on a shaft 32 and the ends of the shaft are secured 
within aligned openings in the respective clamping plates 28. Shaft 32 is 
secured against rotation by forming the ends of shaft 32 with a 
non-circular configuration, such as a D-shape, as shown in FIG. 4 by 32a, 
and the ends 32a are received in complementary openings in plate 28 of 
clamp 25. As rollers 31 are mounted to clamps 25, the rollers are removed 
from the conveyor frame with the clamps and this facilitates belt removal 
and replacement. 
The lower surface of each clamping plate 28 is provided with a threaded 
opening and a screw 33 extends through a suitable opening in base 2 and is 
threaded within the opening to secure the side rail to the base 2. With 
this construction the clamps 25 are slidable on the ribs 20, so that the 
clamps can be positioned anywhere along the length of the conveyor frame. 
Clamps 25 can also be used to attach auxiliary components to the conveyor 
frame. For example, a drive unit for driving belt 7 can be suspended from 
conveyor frame 3 by clamps 25 and this attachment enables the drive unit 
to be moved to any desired location along the length of the conveyor 
frame. 
Each cross member 5 is formed with a longitudinal, upwardly facing T-shaped 
slot 34, as well as a longitudinal downwardly facing T-shaped slot 35, as 
shown in FIG. 7. A group of nuts 36 are slidably mounted in the upper slot 
34 and screws 37 extend through suitable openings in bed plate 6 and are 
threaded in nuts 36 to secure the bed plate to the cross members. 
To connect the cross members to the side rails 4, the ends of each cross 
member are formed with a pair of tapped holes 38. Connecting screws 39 
extend through holes in inner wall 15 of the side rail and are threaded in 
the holes 38. As shown in FIG. 2, stiffening bars 40, which are preferably 
formed of steel and are generally rectangular in cross section, can be 
positioned against the inner surface of wall 15 of side rails 4 and extend 
a substantial portion of the length of the conveyor frame. In the area of 
stiffening bars 40, the connecting screws 39 also extend through holes in 
the bars. 
Spindle assembly 10 includes a pair of cylindrical sleeves 41 which are 
located in the ends of the spindle 9 and the spindle is journaled on the 
sleeves through a radial bearing 42 and a thrust bearing 43, both of which 
are located within the confines of the spindle. See FIG. 3. The outer end 
of sleeve 41 is formed with an annular collar 44 which is located within 
an opening in plate 45. The outer end of collar 44 is formed with a pair 
of opposed flats 46 which are located approximately 180.degree. apart and 
are received in outer plate 50. The engagement of the flats 46 with slot 
47 prevents rotation of the sleeve 41 relative to the plate 50. Each plate 
50 is connected to the corresponding plate 45 through bolts 52. 
Spindle assembly 10 also includes a pair of slide bars 53 which are mounted 
for movement in the slots 12 of the respective side rails 4, as seen in 
FIG. 3. The outer ends of slide bars 53 are connected together by a cross 
bar unit 54 and screws 55 connect the ends of the cross bar unit to the 
respective slide bars 53. 
To lock the slide bars 53 within the T-slots 12 of the side rails, a pair 
of screws 56 extend through openings in plate 50 and are threaded in holes 
in the corresponding slide bars. By turning down the screws 56, the slide 
bars will be drawn outwardly into engagement with the lips 16 bordering 
the slots 12 to thereby secure the slide bars in the slots 12. 
Spindle assembly 10 is adapted to be moved longitudinally of the conveyor 
frame 3 to adjust the tension on the belt 7 by a rack and pinion 
mechanism. As illustrated, the rack and pinion mechanism includes a pair 
of racks 57, located between side rails 4, and each rack is mounted for 
sliding movement in a guide block 58 which is U-shaped in cross section 
and is connected to the inner surface of wall 15 bordering the T-slot 12 
in the corresponding side rail 4. As shown in FIG. 4, the legs of slide 
block 58 are formed with aligned grooves 60 and a leaf spring 61 is 
received in the aligned grooves. Spring 61 is engaged with the upper 
surface of rack 57 and the force of the spring keeps one lock from locking 
with the pinion. Each guide block 58 is formed with a transverse opening 
and a wear ring 62 is located in each transverse opening, as shown in FIG. 
4. 
As shown in FIG. 3, the outer end of each rack 57 is engaged with cross 
member unit 54 of spindle assembly 10, and by moving the racks outwardly 
the spindle assembly will be correspondingly moved outwardly to apply 
tension to the conveyor belt 7. The inner end of each rack 57 is provided 
with a stop pin 63 which prevents complete displacement of the rack from 
the guide block 58. 
Each rack 57 is moved longitudinally of the conveyor frame by an elongated 
pinion 64, which extends transversely of the conveyor frame. The ends of 
pinion 64 projects through the aligned openings in guide blocks 58 and are 
mounted for rotation in the wear rings 62. The teeth on the pinion 64 are 
engaged with the teeth of the racks 57 and by rotating the pinion, the 
racks will be moved, in unison, longitudinally of the conveyor frame 3 to 
thereby move spindle assembly 10 and apply tension to the belt. 
To rotate the pinion 64, one or both ends of the pinion are provided with a 
hex-shaped hole 65 which is exposed through an opening in inner wall 15 of 
the side rail. Through use of a hex tool, pinion 64 can be rotated to 
thereby adjust the tension on the belt 7. After the proper tension is 
achieved, the spindle assembly 10 can be locked in position relative to 
the conveyor frame 3 by turning down the screws 56. 
The invention also includes a belt tracking mechanism which enables the 
belt 7 to be skewed to provide proper tracking on the conveyor frame 3. 
The belt tracking mechanism includes a cam block 66 which is mounted for 
sliding movement in the slot 12 of each side rail. A cam or eccentric 67 
is mounted for rotation on one end of each cam block 66 and is provided 
with a cam surface 68 which is disposed to engage the end of the 
respective slide bar 53, as illustrated in FIG. 3. Cam block 66 is secured 
to the respective side rail through use of a cover plate 69 which bears 
against the outer surface of the side rail and a pair of screws 70 extend 
through openings in the cover plate and are threaded in openings in the 
cam block. By tightening down screws 70, cam block 66 will be drawn 
outwardly into tight engagement with the lips 16 bordering the slot 12 to 
secure the cam block to the side rail. 
With each cam block 66 locked in the position, as shown in FIG. 3, and the 
locking screws 56 loosened, the cam 67 can be rotated by inserting a tool 
into the hex-shaped hole 72 in the cam. Rotation of each cam will thus 
move the respective side bar 53 which will tend to skew or tilt the 
spindle assembly 10 and thus provide the desired tracking for the belt 7. 
As a cam 67 is associated with each side bar 53 of the spindle assembly, 
individual rotation of the cams will provide the desired tracking of the 
belt. 
To provide the skewing action for spindle assembly 10, cross bar unit 54 is 
composed of a pair of end members 54a, each of which is connected by 
screws 54b to the respective side plates 45. The inner edge of each end 
member 54a is formed with an open ended slot 54c and the ends of a central 
bar 54d are mounted for horizontal pivotal movement in the respective 
slots by vertical the pins 54e, the spindle assembly 1 can be skewed on 
rotation of one of the cams 67 to thereby provide proper belt tracking. 
To tension and track the belt 7, screws 56 are loosened to permit the 
spindle assembly 10 to slide relative to the side rails 4. Pinion 64 is 
then rotated by engaging a tool in the hex hole 65 causing the racks 57 to 
move outwardly in unison and correspondingly move the spindle assembly 
outwardly until the desired belt tension is achieved. The screws 56 are 
then tightened down to lock the spindle assembly in this position while 
maintaining pressure on the hex wrench which is engaged with the pinion 
64. 
The conveyor belt 7 is then subjected to a test run and checked for proper 
alignment. If the belt tracks toward one side or other, the tracking 
mechanism is then utilized. Screws 70 are loosened, enabling the cam 
blocks 66 to be slid outwardly in slots 12 until the cam blocks engage the 
inner ends of the slide bars 53 of the spindle assembly. The screws 70 are 
then turned down to lock the cam blocks 66 to the side rails 4. Screws 56 
are then loosened and one or both of the cams 67 are then rotated through 
use of a hex wrench to provide the proper tracking for the belt. When 
proper tracking is achieved, the screws 56 are tightened down to lock the 
spindle assembly in that orientation. As the belt tracking operation is 
separate from the belt tensioning, the tracking can be performed by 
unskilled workmen. The use of the cams 67 provides an infinite adjustment 
for each side of the spindle assembly 10 to provide the proper tracking of 
the belt. 
Small parts or articles, particularly if they are coated with oil, may tend 
to stick to the conveyor and not be discharged from the downstream end of 
the conveyor. To ensure that the parts are removed from the conveyor, a 
wiper 73 is located at the downstream end of the conveyor, or at both ends 
if the conveyor is reversible, and is connected between the plates 50. As 
shown in FIGS. 1 and 6, each plate 45 is provided with an opening 73a and 
the ends of the wiper are disposed within the aligned openings. Attachment 
of the outer plates 50 over the plates 45 will thus retain the wiper 73 in 
position. The openings 73a have a contour to receive either of two wiper 
configurations. For example, in one configuration, as shown in FIGS. 1 and 
6, the wiper 73 is provided with a tapered or sharpened edge 74 which 
rides against the lower run of belt 7 to remove any articles that may 
adhere to the belt, after the belt passes around the spindle 8 at the end 
of the conveyor. Wiper 73 also acts to urge the belt upwardly towards the 
spindle 8. 
In a second configuration, as illustrated in FIG. 14, the wiper 73b has an 
elongated generally rectangular cross section and is received in the lower 
ends of openings 73a. A wiper similar to 73b is used where the belt 7 may 
have a sticky conveying surface or in situations where the joint between 
the ends is enlarged. The openings 73a will thus accommodate either wiper 
configuration. 
As a feature of the invention, spring nuts 75 can be utilized to attach 
relatively light weight auxiliary components or equipment to the conveyor 
frame 3. The auxiliary components may comprise guides, arches, movable 
stops, photo eyes or sensors, and the like. Each nut 75 is mounted for 
sliding movement in the T-slot 12 of side rail 4 and the nut is provided 
with a central threaded opening 76 which can receive a screw, or other 
fastener, to attach the component to the nut. 
As best seen in FIG. 9, each nut 75 is provided with a generally square 
outer section 77 and a rectangular inner section 78. Opposed corners of 
the rectangular section 78 are rounded as indicated by 79. The outer 
surface of square outer section 77 is provided with a group of diagonal 
grooves 80 which are adapted to receive a screwdriver or other tool to 
rotate the nut. 
The inner surface of the rectangular section 78 is formed with a recess 81 
which borders the opening 76, and the large diameter end of a tapered coil 
spring 82 is received within the recess while the opposite end of the 
spring bears against the inner wall 15 bordering slot 12 The force of the 
spring 82 will urge the nut outwardly, with the square outer section 77 
being located between lips 16 of the side rail. The tapered configuration 
prevents the coils of the spring from hanging up in the recess 81 when the 
spring is compressed. 
To install the nut 75, the narrow dimension of rectangular section 78 is 
aligned with the outer portion of slot 12 between lip 16 and the nut is 
then inserted into the slot 12. Using a tool engaged with the grooves 80, 
the nut is then rotated which will bring the wider dimension of the 
rectangular section 78 into engagement with the walls 13 and 14 bordering 
slot 12, thus locking the nut against longitudinal movement within the 
slot. The force of the spring 82 will urge the nut outwardly to position 
the outer square section 77 between the lips 16, thereby locking the nut 
against rotation. One or more brackets 83 which carry auxiliary components 
can then be connected to the nut through use of a screw 83a which engages 
the opening 76 in the nut 75. 
The construction of the spring nuts 75 enables the nuts to be inserted into 
the T-slot 12 anywhere along the length of the slot and then locked in 
position. Thus, it is not necessary to insert the nuts into the open ends 
of the slot, for the open ends of the slot normally contain other 
components, such as the slide bars 53, which would prevent insertion of 
the nuts into the open ends of the slots 12. 
The conveyor of the invention provides a construction which enables the 
belt to be readily removed for maintenance or repair. To remove the belt, 
any auxiliary components attached through brackets 83 can be initially 
removed from the conveyor frame 3, and the spindle assembly can then be 
moved inwardly to slacken the belt. The belt can then be slipped laterally 
from the conveyor frame. 
In addition, the construction of the invention provides a simple and 
effective mechanism for precisely adjusting the tension and tracking of 
the belt. It is contemplated that the tracking mechanism can be used 
without the tensioning mechanism to adjust the tracking of a belt that is 
trained on a spindle or roller that is movable longitudinally relative to 
the conveyor frame. 
The conveyor can be readily attached to a supporting structure or base 
through use of the clamps 25 and various auxiliary components can be 
readily attached anywhere along the length of the conveyor through use of 
the spring nuts 75. 
FIGS. 10-13 illustrate a modified form of the invention utilizing a pair of 
spaced parallel conveyors 84. Each conveyor includes an outer side rail 
85, similar in construction to side rails 4 of the first embodiment, and 
having a generally T-shaped longitudinal slot 86. In addition, each side 
rail 85 is formed with an upper groove 87 and a lower outwardly extending 
rib or flange 88, similar in construction and function to groove 19 and 
rib 20 in side rails 4 as previously described. 
Generally rectangular stiffening members 89, similar to stiffeners 40, are 
mounted on the inner surface of each side rail 85 and a plurality of cross 
members 90, similar to cross members 5, are connected between the 
stiffeners 89, in the manner previously described. 
Each conveyor also includes a flat bed plate 91 which is supported on the 
upper surfaces of the cross members 90, as well as on the respective 
stiffener 89 and side rail 85. A conveyor belt 92 rides on the upper 
surface of bed plate 91, as shown in FIG. 12 
An upper side guide 93 is connected to the upper surfaces of cross members 
90, as seen in FIG. 12, and extends along the inner side edge of the belt 
92 of each conveyor 84. The side guides can be connected to the cross 
members, as previously described, by screws 94 which extend through 
openings in the side guides and are engaged with nuts 95 which are mounted 
for sliding movement within longitudinal slots 96 in the upper surface of 
the cross members 90. 
In addition to the upper guide 93, an angle-shaped lower guide 97 can be 
mounted to the lower surfaces of the cross members 90 and is located 
adjacent the side edge of the lower run of the corresponding belt 92. As 
in the case of the upper guides 93, the lower guides 97 are connected to 
the cross members by screws 98 which extend through openings in the upper 
flange or the lower guides and are received within nuts 99 which are 
slidable within the lower grooves or slots 100 in the cross members 90, as 
seen in FIG. 12. 
The belts 92 of the two conveyors 84 are driven by a common drive spindle 
101 which extends between the outer side rails 85 of the conveyors. Drive 
spindle 101 can be operably connected to a suitable drive mechanism, such 
as a hydraulic or electric motor, in a conventional manner and rotation of 
the drive spindle 101 will serve to drive the belts 92 of the two 
conveyors 84 in unison. 
The end of each conveyor 84, opposite the end which carries the drive 
spindle 101, projects beyond the last cross member 90 of the series and an 
inner side rail section 102 is connected to the projecting end of each 
outer side rail 85. Each side rail section 102 is formed with a 
longitudinal T-shaped slot 103, as shown in FIG. 13. However, the upwardly 
extending flange 104 of the side rail section 102 terminates beneath the 
level of the belt 92, as shown in FIG. 13, so that an article to be 
conveyed can span the distance between the conveyors 84 without 
interference from the side rail sections 102. 
The projecting end of each conveyor 84 includes a spindle assembly 105, 
similar to spindle assembly 10, previously described. Each spindle 
assembly 105 includes a pair of parallel slide bars 106 which are slidable 
in the slot 86 in the side rail 85 and in the slot 103 of the side rail 
section 102. The spindle assembly 105 of each conveyor can be moved 
longitudinally of the conveyor by a rack and pinion tensioning mechanism 
similar to that previously described. As illustrated, each conveyor 84 is 
relatively narrow in width and therefore only a single rack 107 is 
utilized with each conveyor. As shown in FIGS. 11 and 13, a guide block 
108 is secured centrally between the side rail 86 and the respective inner 
side rail section 102, and rack 107, similar to rack 57 of the first 
embodiment, is mounted for sliding movement in the guide block 108. The 
outer end of the rack is adapted to engage the cross member of spindle 
assembly 105, as previously described. A pinion 109, similar to pinion 64, 
extends transversely across each conveyor 84 and is journaled for rotation 
in a pair of wear rings 110 bordering a transverse opening in guide block 
108. Through rotation of pinion 109, the rack 107 can be moved 
longitudinally to thereby move the spindle assembly 105 and adjust the 
tension on the belt 92, as previously described. 
The embodiment as shown in FIGS. 10-13 also includes a tracking mechanism 
similar to that described in the first embodiment. Cam blocks 111 are 
mounted for sliding movement in the slot 86 of side rail 85, as well as in 
the slot 103 of side rail section 102 of each conveyor, and a cam 112, 
similar to cam 67, is mounted for rotation relative to each cam block. 
Through rotation of each cam 112, as previously described, each side bar 
106 of the spindle assembly 105 can be individually moved relative to the 
conveyor frame to provide proper tracking for each conveyor belt 92. 
FIGS. 14-16 illustrate a construction for attaching heavier weight or 
larger components to the conveyor frame utilizing an elongated bar 110 
having a generally T-shaped cross section. Bar 110 comprises a generally 
rectangular outer section 11 and an inner section 112 having tapered inner 
edges 113. A pair of spaced threaded holes 114 extend through bar 110. 
As seen in FIG. 15, the front-to-rear dimension of bar 110 is less than the 
distance between lips 16 of side rail 14 so that the bar can be inserted 
into slot 12. After insertion into slot 12, bar 110 is rotated 90.degree. 
to the position shown in FIG. 16. The tapered or beveled edges 113 permit 
the bar to be rotated in the slot 12 and after rotation, the section 111 
is then moved outwardly between lips 16 to the lock the bar against 
rotation. The vertical dimension section 111 is slightly less than the 
vertical distance between legs 16. 
An auxiliary component 115 can be attached to bar 110 by bolts 116 which 
are threaded in holes 114. 
With this construction, bars 110 can be slid within slots 12 anywhere along 
the length of the side rails 4 to properly position the components 116. As 
the bar 110 has a substantial length, it will effectively resist any 
rotation force applied to the bar by large size or heavy components, such 
as motors, that may be attached to the conveyor frame. 
Various modes of carrying out the invention are contemplated as being 
within the scope of the following claims particularly pointing out and 
distinctly claiming the subject matter which is regarded as the invention.