Note: Descriptions are shown in the official language in which they were submitted.
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CONVEYOR
BACKGROUND OF THE INVENTION
~he present invention relates to oonveyors, and, in
particular, to conveyors which utilize a roller chain for
carrying the articles to be conveyed.
It is known to use roller chains for conveying
articles alon~ a conveyor. However, there have been
~everal shortcomings with these conveyors.
Flrst, debris can fall into the chain from above,
causing the rollers to jam and stop rotating, which
greatly increases the friction and eliminates the
benefit~ of usin~ a roller chain.
Second, when articles that are being conveyed are
stopped, an additional friction load is placed on the
conveyor drive.
Third, the construction of a conveyor frame is
usually quite expensive. A big part of the expense is
that epecial guides must be constructed and mounted to
the conveyor frame f or guiding the articles to be
conveyed.
Fourth, there has been no convenient way for
attaching air hoses, wires, and other tubular-shaped
items to the conveyor frame.
Fifth, it is often difficult to match up a drive to
the conveyor frame, and guides typically must stop at the
: drive, so there is a space in which the articles are not
: guidsd.
Sixth, it is of~t~n difficult to remove drives for
maintenance purpose ost drives require clearance at
: 30 the end of the conveyor, which conflicts with the
frequent need to place the end of the conveyor up against
another conveyor ox piece of equipment.
Seventh, in some case~ it is desirable to be able to
make the support surface or rail out of a different
material from the frame. For sxample, it may be
desirahle to make the rails out of a harder material or a
higher friction makerial, and to change from one material
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to another depending upon the product~ to be carried. It
is possible to make removable rails which can be made out
of any desi.red material. However, in the prior art, the
removable rails had to have a special shap~ in order to
be mounted on the conveyor frame, and the rails could
only be installed or removed from the end of the conveyor
frame, meaning that the frame had to be disassembled in
order to change the rails. That meant that changing out
worn rails or changing the material of the rails to set
up the conveyor to carry a new type of product was very
time consuming and ~xpensive, both because it took a lot
of labor to take the conveyor apart and chan~e the rails
and because the conveyor was shut down and unable to
function duxing that whole time~ thereby shutting down a
warehouse or a production ~acility during that entire
period of time.
SUMMARY OF T~E lNv~ lON
The present invention solves many of the problems of
the prior art. For example, the present invention
provides a modular conveyor frame construction with guide
slots into which inexpensive guides can easily be
attached. The-modular frame con~truction al60 provide~
convenient means for attaching air hoses, wire~, and
other tubular-shaped items to the frame.
The present invention also provides a clip which can
be inserted between~adjacent rollers of the roller chain
; in order ko prevent debris from getting into the chain
and jamming the rollers.
: The pre~ent invention also provides a conveyor stop
attachment which lifts the articles up off o~ the
conveyor chain, thereby eliminating any load on the drive
when articles are accumulated on the conveyor.
The conveyor stop attachment is made to hQok
directly onto the conveyor frame, which eliminates
alignment problems between the attachment and the
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conveyor frame.
The present invention also provides a drive housing
which is readily attached to the modular frame and which
has an exterior shape that conforms to the modular frame.
The drive housing include6 the guide slQt, so the
~uide ca~ extend to the end of the conveyor, and the
driv~ housing is mounted on the conveyor frame in such a
way that it can be removed by lifting it up vertically --
requiring no clearance at the end o~ the conveyor.
The drive housing also includes an opening, which
permits debris on the top of the chain to fall off th~
chain, without being wedged in the chain or housing.
: The present invention provides a frame with
removable ~ails that are made out of plain bar ~tock,
~5 requiring no specially-formed rail~.
The present invention also provides removable rail~
which can be removed from the top of the frame, meaning
that the frame does not have to be disassembled in order
to remove and replace the rails. This saves labor and
means that the rail6 can be changed out very quickly,
avoiding expensive s~ut-downs of the ronveyor.
: ~ BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic top view of a conveyor made
in accordance with the present invention;
Figuxe 2 is a sectional view taken along the section
:: 2-2 of Figure 1;
Figure 3 is a sectional view of a portion of the
conveyor of Figure 1, with horizontal guides installed on
the conveyor; ~ -
Figure 4 is an exploded perspective view o~ one side
of the stop mechanism shown in Figure 2;
Figure 5 is a schematic view of the control
arrangement ~or the stop of Figure 1;
Figure 6 is an alternative em~od~ ?nt of the stop
tread o~ Figure 4;
Figure 7 is an enlarged per6pective view of a clip
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which is used in the chain of the conveyor of Figure 1;
Figure 8 is a broken-away top view of the chain of
the conveyor o~ Figure 1, with the clips of Figure 7
installed on the chain;
Figure 9 is a slde sectional view of the chain shown
in Figure 8S
Figure 10 is a perspective view of the chain shown
in Figure ~;
Figure 11 is a perspective vie~ of the drive portion
of one side of the conveyor shown in Figure 1 with the
drive portion exploded away;
Figure 12 is an exploded perspective view of the
drive portion of Figure 11;
Figure 13 is a schematic side sectional view of the
conveyor of Figure 1, showing the driva end and the idler
end;
Figure 14 i5 a perspective view of an alternative
embodiment of the drive end of the conveyor;
Figure 15 is a perspec~ive view of one of the
connec~or strips which connects the drive housing o~
Figure 14 to the conveyor ~rame;
Figure 16 is a right side view of the drive of
Figure 13;
::; Figure 17 is a ri~ht slde view of the drive o~
Figure 13, with a drive gear box installed on the outside
of the drive housing and with the drive housing removed
from the conveyor frame;
Figure 18 is a sectional view through the portion of
the conveyor frame shown in Figure l~; -
Figure 19 i8 a top ~iew of the le~t half of the
drive shown in Figure 14;
Figure 20 i6 the same view as Figure 3 but showing
an alternative embodiment of the invention in which the
support track is removable;
Figure 21 is an enlarged view o~ the right frame
portion of ~igurP 20j partially in section, with one o~
the rail retaining crews removed;
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Figure 22 i8 a view o~ the top portion of ~igure 21,
DartiallY in section. before the riaht retainina ~crew
hole has been drilled out and before the rails have been
installed; and
Figure 23 is a perspective view of the frame of
Figure 21 with the rails removed.
D~SCRIPTION OF THE PREFERRED EMBODIMENTS
The conveyor 10 of the present invention, as shown
in the figures described abovie, includes a drive shaft
12, which connects together two parallel sats of drive
sprockets 16. At the other end of the conveyor, there
are two parallel sets of idler sprockets 14. The drive
sprockets I6 on the left side of the conveyor are used to
drive a left chain 18 t and the drive sprockets 16 on the
right side of the conveyor are used to drive a right
chain 20~
: The left and xight chains 18, 20 run parallel to
each other in parallel left and right frame portions 22,
24, respectively. The left and right frame portions are
preferably modular extruded parts which can be fastened
together to make the conveyor 10 cany desired size. These
: : modular extruded paxts 22, 24 define an upper ch.-her 26,
which receives.the upper run of the ~hain 18 or 20, and a
: lower chamber 28, which receives t,he lower run o~ the
: 25 chain.
The chains 18, 20 are available on the market. One
such chain is sold under the name of Tsubaki Double Plus
:
chain. The chain~ 18, 20 are made up of a plurality of
links 2I, with each link 21 made up of a forward large
roller 30 flanked by two small~r rollers 34 connected
kogether by a chain pin 27, a rear large roller 30
flanked by two smaller rollers 34 connected toyether by a
chain pin 27, and a pair of inner side bars 29 connected
ko said forward rollers and rear rollers by means of the
chain pin~i 27. The forward set of rollers 30,34 and rear
iset of rollers 30, 34 for~ the ~ront and back ends o~ a
2~ ~2~
rectangl~, and the sides o~ the rectangle are formed by
the inner side bars 29. The link~ 21 are connected
together by outer side bar~ 31, which are fastened to the
rear of one link and the front of the next adjacent link
by means of the chain pins 27.
The lower chambers 2B of both frame portions 22, 24
are completely enclosed on the top, bo~tom, left and
right sides. The upper chambers 26 are enclosed on the
left and right sides and on the bottom, and are partially
enclosed on the top, with only the large central roller
30 of the chain 18, 20 projecting above the top surface
of the frame portions 22, 24 for contacting the pallet or
other article to be conveyed. Both the upper and lower
chambers 26, 28 provide raised rails 32 for supportinq
the ~maller-sized rollers 34 in rolling engagement. As
can be seen from the drawings, the le~t and right frame
portion~ 22, 24 are mirror images of each other. To
achieve the mirror image~, identical extrusions are
simply run in opposite directions.
As is shown in Figures 2 and 3, the le~t and right
~rame members 22, 24 define a rectangular vertical ~lot
36 opening outward from their upper surface 38 adjacent
their outsidP edge 40. The vertical slots 36 are taller
than they are wide and are used to ~upport guide rails
42. The height of the vertical slots is preferably at
lea6t two times the width. The width o~ the vertical
slots 36 is preferably some ~tandard size, such as 1/4",
or 3/8" so that it can accept a standard, off-the-shelf
piec~ of bar ~tock.
Unlike prior art designs, in which the yuide rails
must be spe¢ially made to bolt to the conveyor ~rame,
these vertical 510ts can receive any available bar stock.
For example, a 1/4"-wide guide slot might receive a l/4"
bar made of ultra high molecular weight polyethylene or
steel. In this manner, guide rails 42 are simple,
inexpensive, and can be placed ~n any locakion or
locations along khe conveyor as needed. In order to
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~ecure the guide rail on the frame, holes (not ~hown~ may
be drilled through the frame and screws (not shown)
inserted through the holes and into the bar stock, or
other known f astening means may be used. These screws or
other fastening means are inserted at regular intervals
along the length of the guide rail, such a~ at 18-inch
intervals. The ~ertical ~uide rail slots 36 are
continued into the housing 44 for the drive sprocXets 16
and into the identical housing 44 for the idler sprockets
lo 14, so that the guide ra;ls 42 may extend along the
hou6ings 44 as well, providing a continuous guide sur~ace
along the entire length of the conveyor.
~ach frame portion 22, 24 also has a horizontal
guide slot 46 defined in the inwardly-facing side 4~ of
the frame portion 22, 24 adjacent to the upper surface
38. These horizontal guide slots 46 are rectangular and
are at least ~s wide as they are tall. As ~hown in
Figure 3, thesa slots 46 are adapted to receive standard
bar stock 50, which ~erves a~ an inexpensive horizontal
guide ~urface for guîding along a downw~rdly projecting
cam roller 52 on the underside of a pallet 54. Again,
the guide material is fastened to the frame with screws
or other known fastening means at regular intervals (not
shown).
In the section of the conveyGr shown in Figure 3, an
insert strip 55 has been placed between the rails 32 in
both of the upper chambers 26. The insert strips 55 may
be u~ed in a part of the conveyor where better traction
is reguired. These insert strips 55 contact the large
central rollers 30 and are thick enough to lift the small
~ide rollers 34 slightly off the rails 32, so that the
chain 18, 20 is rolling along wi~h the large rollers 30
supporting the weight o~ the product on the insert strip
55.
This yives a more positive drive and better traction
than when the small rollers 34 are riding on the rails
32. At the same time, it carries the produat along at a
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somewhat slower rate than when the small rollers 34
support the load, so it is generally used only when
greater traction is required. With the desi~n shown in
these drawings, when the small rollers 34 support the
load, they cause the large rollers 30 to rotate and carry
the articles along at 2~5 times the chain ~pePd. When
the large rollers 30 carry the load, the products are
carriPd at t~o kimes the chain speed.
The frame portions 22, 24 also have T-shaped slots
56 in their left, right, and lower surfaces for attaching
items to the frame portions 22, 24, for attaching the
frame portions 22, 24 to vertical supports 58, and ~o
~orth, by means of bolts with T-shaped heads (no~ ~hown
but known in the art). The bottom surfaces of the frame
members 22, 24 define left and right tu~ular slots 62
which have a rounded internal cross-sectional shape and
which have an opening width 64 that is smaller than the
diameter 66 of the rounded internal portion. These
tubular slots 62 are intended to be used for receiving
air hoses, wires, and other tubular-shaped items which
run along the conveyor. The narrower opening 64 prevents
these items from faIling out of the slot 62 once they
are inserted. It is also possible to use the tubular
slots 62 to receiv~ a downwardly-projecting guard sheet
(not shown)O
Figure 2 shows two stop attachments Ç8 mounted
opposite each other on the inside surfaces of the left
and right frams portions 22, 24. Each of the stop
attachments 68 includes an extruded, elongated frame 70
which defines an elongated hook 72 along its outer edge.
The hook 72 fits into the upper inside T-slot 56 of the
~rame portion and hangs on the ~rame port1On. ThQ stop
frame 70 also has T shaped slots 56 in its lower surface.
Pxeferably, an angle bracket (not shown) is mounted on
sach end of the stop frame 70 and receives T-shaped
bolts, which fit into the T-shaped slots of the conveyor
fr~me. If the sides o~ the pallets 54 extend past the
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sides of the left and right frames 24, 26, the stop
frames 70 may be mounted on the outside o~ the frames 24,
.
Each stop frame 70 defines an elongated bladder
chamber 76 with a lower portion 78 having an inverted T-
shaped cross-section. The stop chamber 76 is clo~ed on
the bottom and sides and open on the top, with the
ch~ hPr tapering inwardly toward the top. An elongated
bladder 80 with a bottom portion having an inverted T
shaped cross-sectio~ slides into the chamber 76 of the
stop, with the T-shaped bottom 82 of the bladder 80
fitting into the T-shaped lower portion of the stop
chamber 76~ The main body of the bladder 80 projects
above the T-shaped slot 78. A tread 84 lies in the stop
chamber 76 on top of the bladder 80. The tread 84 shown
in Figures 2 and 4 has a wide base and taper~ upward, so
that the upper portion of the tread 84 can pro~ect
upwardly through the top opening of the stop frame, while
the wide ba6e portion is too wide to pass through the
narrow top op~ning, thereby retaining the tread 84 on th~
stop frame 70. An alternative tr~aad 84A is shown in
Figure 6. This tread 84A has a w:ide base and a
rectangular cross-section upper portion. Again, the
upper portion fits through the top opening of the bladder
chamber 7~ while the ba~e i~ too wide to pas~ through the
top opening of the bladder chA~h~r and i~ thereby
retained. The tread 84A also has chamfered forward and
rear top edges 85 to provide a smooth transition from the
stop to the conveyor chain. The tread 84A also has a
tread design 87 molded:into it~ top surface, which helps
the tread 84A cut through oil and grease.
By using a tread member 84 or 84A which is ~eparate
from the bladder 80, the most euitable materials may be
selected for the tread 84 and bladder 80, and materials
may be chang2d from one application to another ~ithout
changing the design. The bladder material should be
something with high elastlcity, while the tread material
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should be durable and have a high coefficient of
friction.
Figure 5 shows the control mechanism for the stops.
A sensor 86 senses the presence of a pallet over the ~top
mechanism. This causes the valve 88 to be moved to the
position shown in Figure 5, with pressurized air entering
the parallel bladders 80 causing the treads 84 to shift
upwardly, lifting the pallet up off of the frames 24, 26.
To release the pallet, the valve 88 is shifted to iks
second position, shutting off communication with the
pressurized air source and permitting the air to be
vented from the bladders 80 to the atmosphere. The
bladders 80 preferably have a total travel o~ about 3/8
of an inch, so that the tread ~4 normally lies lt8 inch
below the top o~ the large rollers 30, and, when the
bladders 80 are inflated, the tread 84 lies 1/4 inch
above the top of the large rollers 30. In any case, the
bladders ~0 should at least have 1/4 inch of travel. The
air hoses 90 which control the bladders 80 run in the
tubular ~lots 62 o~ the frame portions 22, 24 and in the
circular recess ~2 o~ the stop frame 70. The hoses 90
terminate at the respective openings 94 in the bladders
80 with a sealed fit.
:~s shown in Figure 1, a pallet: ~arts out on the
right of the conveyor, moves to he left until it reache~
: the stop 6~, an~ then, if the stop 68 is triggered, the
pallet 54 i8 lifted up off the ronveyor. When the stop
is re~eased, the weight of the pallet 54 pushes the air
out of the bladder 80, putting the pallet 54 back down on
the moving roller chains 18, 20 so it can be carried off
~o the left, as ~hown.
Referring to Figures 11 and 12, the sprocket
housing6 44 at each end of the conveyor 10 are identical
to each other and are made to conform to the shape of the
frames 22, 24. The hou6ings 44 include side projections
96 which extend into the side T-slot~ 56 on the frame
members and have hole~ for receiving T-bolts to lock the
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housings 44 on the frames 22, 24. The housings 44 al80
include lower projections 98 which lie below-the frame
22, 24 and have holes that align with the T-slots in the
bottom of the ~rame 22, 24.
The inner surfaces of the housings 44 continue the
horizo~tal guide slot 46 of the frame, so that horizontal
gul~es can ex~enu a1mosl ~o ~ne ena or ~ne conveyor. Tne
upper surfaces of the housings 44 continue the vertical
guide slot 36 of the frame, so that vertical guides can
extend the entire length of the conveyor.
Inside the housings 44 are chain guides 100, 102
which provide rails 32 for receiving the small side
rollers 34 while enclosing all but the top surface of the
chain~on its upper run. The idler sprockets 14, and
drive sprockets 16 are double sprockets, adapted to
straddle the center roIler 30 and contact kha small side
rollers 34.
As shown in Figure 13, there is a drive sprocket
chain stripper 103 in the housing 44 for the dr~ve
sprockets 16, which 8it5 between the sprockets 16 and is
bolted to the housing 44. The drive sprocket chain
stripper 103 provides a guide surface 107 for peeling the
chain 18 or 20 off of the drive sprockets 16. In the
prior art, it was necessary to make the chain very long
~o that a lon~ loop of chain (a catenary) extended from
the drive sprockets 16 toward the floor in order to
prevent the chain from txying to wrap up on the sprockets
: I6. The drive sprocket chain stripper 103 permits the
chain to be just lonq enough to go around the drive
sprockets 16 and the idler sprockets:14 and eliminates
that catenary chain.
There i8 also an idler ~procket chain stripper 105
in the housing 44 at the idler end of the conveyor, which
keeps the chain in line as it goes over the top of the
idler sprocket~ 14. The idler sprocket chain stripper
105 sits between the idler sprockets 1~ in the housing 44
and is bolted to the housingO It provides a guide
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surface 109 which guides the chain 18 or 20 from the
idler sprockets 14 onto the rails 32 of the frame 22 or
24. The two housing halves 44A, 44B ~re bolted together
in both the idler sprocket housing and the drive sprocket
5 housing.
Clips 104, as shown in Yigure 7, are inserted
between adjacent large rollers 30 in order to prevent
debris from entering the spaces in the chains 18, 20 and
jamming the rollers. The clips 104 have a flat top
lO surface 106 with three downwardly-projecting legs 108,
110. The outer legs 108 curve forward, and the inner leg
110 curves backward. Between the top sur~ace 106 and the
: legs 108, 110 are curved forward and rear sides 112, 114,
re6pectively. The curved forward side 112 and forward
15 leg 108 wrap partially around the forward large central
roller 30 with a clearance ~it, and the curved rear ~ide
114 and rear legs 110 wrap partially around the rear
: large central roller 30 with a clearance fit. From the
point where the top ~urfac2 106 of the clip touche~ the
20 roller 30 to the bottom of the legs 108, 110 covers
approximately 45 degxees tor one-fourth o~ the
circum~erence) of the roller. The front-to-back length
of the top surface 106 of the clip 104 is ~hort enough
that it permit~ a portion o~ the center roller 30 to
25 project above the clip 104 to carry the pallets but long
enough that it rests on the large central rollers 30 at
both ends. The front-to-back length of the clip top 106
must be less than the center-to-center distance between
the forward and rear rollers. When an article is carried
30 on top of the center rollers 30, that article does not
touch the clips 104, which lie below.
~he width of the flat top surface 106 is the same as
the width of the central roller 30. The clip 104 also
has two flat wings 116 projecting outwardly a~ a lower
35 height than the top surface 106 to cover the gap between
the two adjacent ~mall 6ide rollers 34. The win~s 116
are longer than the top 8ur~ace 106 in order for the
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front and back of each wing to span the gap ~etween its
respective front and rear small roller 34. The wings 116
are approximately the same width as the small side
rollers. By closing off the gaps in tha chain, the clips
104 prevent debris from falling down into the chain,
thereby eliminating a serious problem wi~h roller chains.
In order to install the clips 104 on the chain, the
bottoms of the front and rear legs 108, 110 are squeezed
together, until t~e leys 108, 110 can fit through the
narrowest portion of the gap between adjacent rollers 30.
Then, the legs 108, 110 snap back to their original
: shape, wrappin~ around the front and rear adjacent
rollers 30 with a clearance fit so that they do not
interfere with the rotation of the rollers but are
retained on the chain.
The drive housings 144 ~hown in Figures 14~ ~6, 17,
and 19 are substantially identical to the drivs housing
44 shown in Figures 11 and 12, except that they include
T-slots 56A which ar~ alignèd with the T-slots 56 in the
frame members 22, 24, and T-slots 57, which are used for
mount~ng a gearmotor ~rive 120. l~hey do not include the
projections 96 which are on the housings 44. A~ is shown
in Figure 17, the gearmotor drive 120 is mounted on the
~ outside of the right drive housinq 1i4. The gearmotor
drive 120 i6 simply slid over the keyed drive sha~t 12,
and the torque arm 122 of the drive 120 is mounted to one
of the T slots 57 by means of a screw in order to prevent
the drive 120 from spinning relative to the drive housing
144. This means that the gearmotor drive 120 can be
removed by removing a single screw or bolt. The
gearmotor drive 120 could alternatively be mounted on the
other side of the right drive housin~ 144 or on either
side of the left drive housing 144, depending on which
location i~ most convenient.
The drive housings 144 are mounted to their
respective frame members 22, 24 by means of mounting
~trip~ 124. The mounting strips 1~4 may have a T-shaped
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cross-section conforming to the cross-section o~ the T-
shaped slots 56, 56A, or they may simply be flat ~trips
(not shown). The mounting strips 124 are slid into their
respecti~e T-slots 56 or 56A, the drive housings 144 are
aligned with their respective frame members 22, 24 until
the respective T-slots 56 and 56A are aligned with each
other, and the mounting strips 124 are then slid so that
they bridge the gap between the respective frame member
22, 24 and drive housing 144. With the connecting strips
124 extending into the housing 144 and into the
respective frame member 22, 24, so as to align the
housing and frame member with each other, the set screws
126 are tightPned, wedging the connecting strips 124 in
place against the T-slots, thereby mounting the drive
housings 144 on their respective frame members 22, 24.
To install or remove the drive housing 144 ~rom its
respective frame member 22, 24, the drive housing 144 can
be moved vertically into or out of position, as shown by
the arrows in Figures 14 and 17. This means that the
drive housings 144 can be installed and removed without
any hori~ontal clearance at the end of the conveyor.
As shown in Figure 16, the two housing halves 144A
and 144B are connected together at three points 130, and
there are ~pacers at each of the connèction poin$s 130,
so as to maintain a gap between the left and right
housing halv~s 144A and 144B. Where the chain passe~
over the drive ~procket 16, there is an unobst~ucted
vertical gap 128 between the left and right housing
portions 144A and 144B, which permits debris 132 to fall
o~f the chain 18, 20, through the gap 128, and out of the
housing 144.
Figure 16 shows that this alternative drive housing
144 includes the same chain guides 100, 102 and stripper
103 as the drive housing shown in Figures 11 and 12.
Figure 18 shows a cross sectional view of the right frame
member 24 with the connector strips 124 located in the T~
slots ~6. Figure 19 shows a top ~iew of the drive 144
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mounted on the left frame member 22.
In this alternative embodiment, the idler housings
(not shown) are identical to the drive housings 144,
except that no drive shaft passes through them, and no
gear drive is mounted on them. The idler housings also
can be installed and removed with only vertical movement,
requiring no horizontal clearance.
Figures 20-23 are the ~ame as the embodiment o~ the 'J
invention shown in Figures 2 and 3, except that the
embodiment of Figures 20-23 includes removable support
rails or tracks 232. In Figures 20-23, the parts which
are the same as those described earlier will be given the
same numbers as they had in the previous embodiment or
will be left unnumbered, and the new or changed parts
will be given new numbers.
As in the previous embo~; ~nt, the left and right
frame portions are pre~erably modular extruded parts
which can be fastened together to make the conveyor 10
any desired size. These mod~lar extruded parts 222, 224
have an exterior side 11 and an interior side 13 and
define an upper chamber 2~, which receives the upper run
of the chain 18 or 20l and a lower chamber 28, which
receives the lower run o~ the chain.
The chains ~8, 20 shown in this embodiment o~ the
invention ar~ the same as in the previous embodiment.
The upper chambers 2~ differ from the previous embodiment
in that they provide removable rails 232, which fit into
elongated, top-opening slots 236 for supporting the
smaller-sized rollers 34 on the ~orward, conveying run.
The removable rails 232 are made from o~ the-shelf,
rectangular cross-section bar stock. The top-opening
~lots 236 are also generally rectangular-shaped. 5et
screws 238 are installed at intervals along the conveyor
frame at an angle to push the bar stock inwardly and
downwardly in order to retain the bar stock rail~ in
place. In order to facilitate the installation of the
set screws 238, left and right inclined, elongated
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pockets 240, 242 are extruded in the conveyor frame
inside their respective left and right T-slots 244, 246.
Figure 22 shows the riyht pocket 242 before it has been
drilled out to receive a set screw, and it shows the left
pocket 240 after it has been drilled and tapped for the
installation of a set screw 238. The pockets 240, 242
lie between their respective T-slots 244, 246 and their
respective rail-receiving slots 236, and there are webs
of material separating the pockets 240, 242 from their
respective T-slots and rail-r~ceiving slots.
The left and right set screw pockets 240, 242 run
the length of the frame and have a smaller width than the
diameter of the set screws 238. It is necessary, at
intervals along the conveyor frame, to drill through the
webs of matexial separating the pockets from their
respective slots and to tap the holes to form threads to
receive the set screws 238. The purpose of the set screw
pockets is to reduce the amount of material that has to
be removed by drilling (in order to speed up the
installation) and to provide a pilot so that the an~le
and direction of the drilled hole will be correct.
As can be seen on the right side of Figure 22, the
T-slot 246 is formed with an indicator notch 250, which
indicates where to begin drilling the hole. Once the
holes have been drilled and ~apped and the set screws 238
installed, the removable rails 232 are secured in the
conveyor frames, with the set screws pushing the rails
inwardly and downwardly.
To remove the removable rails 232, the set screws
are removed, the chain 18 or 20 is removed from the upper
run of the conveyor, and the remo~able rails 232 can then
be lifted up out of the top opening of the conveyor
frame, without disassembling the conveyor frameO New
removable rails 232 can be inserted down through the top
opening of the conveyor frame, inserted into their
respective top-opening rail slots 236, and then the set
screws 238 can be inserted again, to hold the new rails
-
2~2~8
17
232 in place.
As can be seen from the drawings, the left and right
~rame portions 222, 224 are mirror images of each other.
To achieve the mirror images, identical extrusions are
simply run in opposite directions.
It will be obvious to those skilled in the art that
modifications may be made to the embodiments described
above without departing from the scope of the present
invention.
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