Reciprocating floor conveyor with liquid collecting base structure

Adjacent base sections of a base structure of a reciprocating floor conveyor are connected along longitudinal side edges by a tongue and groove joint. Side portions of adjacent sections form a guide beam. The groove and tongue portions of the joint are formed at lower ends of angled inner walls extending downwardly from the top of the guide beam. The inner walls together define an upwardly opening space above the joint. The space is large enough, and the groove and tongue portions are spaced below the top of the guide beam a distance sufficient, to permit the joint to be sealed while maintaining the joint, including sealing portions thereof, isolated from the top of the guide beam and from a bearing positioned on the guide beam. The tongue and groove portions together define a sealing space for receiving a flexible sealant to seal the joint. Sealant oozing out of the sealing space into the space above the joint is isolated from the bearing. The joint may also be secured by a weld bead in the space above the joint. A layer of flexible sealant may be placed on top of the bead. Both the bead and the sealant are isolated from the bearing.

TECHNICAL FIELD 
This invention relates to reciprocating floor conveyors and base structures 
therefore and, more particularly, to a base structure having sections 
interconnected along joints that are isolated from the tops of guide beams 
formed by the base structure and bearings positioned on the guide beams. 
BACKGROUND INFORMATION 
Reciprocating floor conveyors are presently being used in a number of 
environments. They are being installed as floors in the bottom of large 
trucks and trailers for use in both loading and unloading cargo. They can 
also be used in railroad cars. The types of loads that may be moved by a 
reciprocating floor conveyor vary widely and include liquid laden loads, 
such as garbage. It is undesirable to allow liquid to drip downwardly from 
a vehicle or railroad car while the vehicle or car is in use. Therefore, 
there is a need for a reciprocating floor conveyor that is substantially 
leakproof. 
The patent literature includes a number of examples of reciprocating floor 
conveyors that are substantially leakproof, or intended to be so. One 
example is disclosed in my U.S. Pat. No. 5,238,360, granted Aug. 24, 1993. 
This patent discloses a conveyor base structure having a plurality of 
longitudinal base sections that are connected together along longitudinal 
side edges. 
The main object of the present invention is to provide an improvement in 
the connection between adjacent base sections in a base structure of a 
reciprocating floor conveyor. 
SUMMARY OF THE INVENTION 
A subject of the present invention is an improved connection between 
adjacent base sections in a reciprocating floor conveyor having a base 
structure that includes a plurality of longitudinal base sections 
connected together along longitudinal side edges. The base structure 
provides a plurality of laterally spaced apart guide beams and channels 
between the guide beams. The guide beams support slide bearings and the 
slide bearings in turn support longitudinal floor members. The floor 
members are moved longitudinally in one direction to convey a load and are 
retracted in the opposite direction. According to an aspect of the 
invention, in the improved connection, each base section includes first 
and second opposite side portions. The first side portion includes a first 
sidewall, a first top portion that forms part of a top of a guide beam, a 
first inner wall extending downwardly from said first top portion, and a 
groove portion of a tongue and groove joint carried by the first inner 
wall. The groove portion includes a laterally outwardly directed groove 
which extends longitudinally of the base section and is spaced below the 
top of the guide beam. The second side portion of the base section 
includes a second sidewall, a second top portion that forms part of the 
top of the guide beam, a second inner wall extending downwardly from the 
second top portion, and a laterally outwardly directed tongue portion of 
the tongue and groove joint carried by the second inner wall. The tongue 
portion extends longitudinally of the base section. The tongue portion of 
each base section extends into a groove portion of an adjacent base 
section to form a tongue and groove joint spaced below the top of the 
guide beam. The first and second inner walls of adjacent first and second 
side portions, respectively, together define an upwardly opening space 
above the joint. The space is large enough, and the groove and tongue 
portions are spaced below the top of the guide beam a distance sufficient, 
to permit the joint to be sealed while maintaining the joint, including 
sealing portions thereof, isolated from an area above a vertical height 
defined by the upper surfaces of the first and second top portions. 
A preferred feature of the connection are first and second inner walls that 
are angled and extend from the first and second top portions, 
respectively, downwardly and laterally outwardly away from the first and 
second sidewalls, respectively. Another preferred feature is the 
positioning of the tongue and groove portions of the joint at lower ends 
of the inner walls. Still another preferred feature is a tongue and groove 
joint that provides vertical and lateral clearance between the groove 
portion and tongue portion to permit relative vertical and lateral 
movement between adjacent base sections. Each of these preferred features 
may be provided individually or in combination with one or more of the 
other preferred features. 
In general, it is preferable that each tongue and groove joint be sealed. 
In one embodiment, the tongue and groove portions of each joint together 
define a sealing space configured to receive a sealing material to seal 
the joint. The upwardly opening space is large enough, and the groove and 
tongue portions are spaced below the top of the guide beam a distance 
sufficient, to maintain the area above the guide beam isolated from 
portions of the sealing material that may ooze out of the sealing space 
and into the upwardly opening space. In another embodiment, in a fully 
assembled conveyor, each joint comprises a weld bead located above the 
tongue and groove portions. The area above the guide beam is isolated from 
the bead. 
Another subject of the invention is a reciprocating floor conveyor 
comprising a base structure, a plurality of slide bearings, and a 
plurality of floor members. According to an aspect of the invention, the 
base structure includes a plurality of longitudinal base sections 
connected together along longitudinal side edges. The base structure 
provides a plurality of laterally spaced apart guide beams and channels 
between the guide beams. Each base section includes first and second 
opposite side portions. The first side portion includes a first sidewall, 
a first top portion that forms part of a top of a guide beam, a first 
inner wall extending downwardly from the first top portion, and a groove 
portion of a tongue and groove joint carried by the first inner wall. The 
second side portion includes a second sidewall, a second top portion that 
forms part of the top of the guide beam, a second inner wall extending 
downwardly from the second top portion, and a laterally outwardly directed 
tongue portion of the tongue and groove joint carried by the second inner 
wall. The tongue portion extends longitudinally of the base section within 
the groove portion of an adjacent base section. There is a slide bearing 
for each guide beam. The slide bearing has a top portion which sets down 
on top of its guide beam. The floor members extend longitudinally of the 
conveyor and are supported by the guide beams. The floor members are 
laterally spaced apart with channels provided by the base structure 
therebetween. The first and second inner walls of adjacent first and 
second side portions, respectively, together define an upwardly opening 
space above the joint. The space is large enough, and the groove and 
tongue portions are spaced below the top of the guide beam a distance 
sufficient, to permit the joint to be sealed while maintaining the joint, 
including sealing portions thereof, isolated from the slide bearing for 
the guide beam. 
The conveyor may in addition have one or more of the preferred features 
discussed above. For example, the tongue and groove joints in the conveyor 
are preferably sealed. They may be sealed as described above or by other 
suitable means.

BEST MODES FOR CARRYING OUT THE INVENTION 
The drawings show two embodiments of a base section 2,102 each of which 
provides an improved connection between adjacent base sections. The 
drawings also show additional related portions of a reciprocating floor 
conveyor. The illustrated structures are constructed according to the 
invention and constitute the best modes for carrying out the invention 
currently known to the applicant. In the drawings, the base sections 2, 
102 are shown in use in a reciprocating floor conveyor along with bearings 
50 and floor members 68. It is currently anticipated that the improved 
connection of the invention will be used in combination with the type of 
bearings and floor members shown in the drawings. However, it is intended 
to be understood that the connection could also be used in combination 
with other types of bearings and other types of floor members without 
departing from the spirit and scope of the invention as defined by the 
claims. 
Referring to FIGS. 1-6, the first embodiment of the base section 2 has 
first and second opposite side portions 4, 18 which provide longitudinal 
side edges along which adjacent base sections 2 are connected together. At 
the junction of two base sections 2, the interconnected side portions 4, 
18 together form a guide beam 4, 18. Each base section 2 also includes an 
integral guide beam 36 positioned between its opposite side portions 4, 
18. The guide beam 36 is spaced apart from the opposite side portions 4, 
18 with channels CH formed by the base section 2 therebetween. 
The details of the first and second side portions 4, 18 are best seen in 
FIG. 2. The first side portion 4 includes a first sidewall 6 that extends 
upwardly from a bottom wall 32 of the base section 2 which forms the 
bottom of one of the channels CH. The sidewall 6 extends upwardly and 
angles slightly laterally away from the bottom wall 32. As can be seen in 
FIG. 2, the bottom portion of the sidewall 6 that extends integrally from 
the bottom wall 32 is curved to form a smooth transition and provide 
increased strength to the base structure. A top portion 8 of the side 
portion 4 extends horizontally from the top of the sidewall 6 in a 
direction opposite to that of the bottom wall 32. The top portion 8 
extends from the sidewall 6 to an outer end from which an angled inner 
wall 10 extends downwardly. The inner wall 10 carries a groove portion 12 
of a tongue and groove joint 12, 26. The groove portion 12 defines a 
laterally outwardly directed groove 14 extending longitudinally of the 
base section 2 for receiving a tongue to thereby connect adjacent base 
sections 2. 
As illustrated, the groove portion 12 is formed on the lower end of the 
angled wall 10. This is presently the preferred configuration of the 
improved connection. However, the groove portion could be carried by the 
inner wall 10 at a location above the bottom of the inner wall 10. For 
example, the groove portion 12 could be carried on a mid portion of the 
inner wall 10 with the inner wall 10 forming a support leg that depends 
downwardly from the groove portion 12. 
The second side portion 18 has a sidewall 20 that extends upwardly and 
laterally away from a bottom wall 34 that forms the bottom of another 
channel CH. The sidewall 20 is essentially a mirror image of the sidewall 
6. The second side portion 18 also includes a top portion 22 and an angled 
inner wall 24. The top portion 22 extends horizontally from the top of the 
sidewall 20 and, in the assembled base structure, toward the top portion 8 
of the first side portion 4 of the adjacent base section 2. The angled 
inner wall 24 extends downwardly from the outer end of the top portion 22. 
A tongue 26 of the tongue and groove joint 12, 26 is carried by the inner 
wall 24 and extends laterally outwardly therefrom. It preferably extends 
from the lower end of the inner wall 24. As shown in FIG. 2, when the 
adjacent base sections 2 are connected together, the tongue 26 of the 
second side portion 18 extends into the groove 14 of the first side 
portion 4 of the adjacent base section 2. 
As noted above, the interconnected adjacent first and second side portions 
4, 16 together form a guide beam. The top portions 8, 22 each form part of 
the top of the guide beam 4, 18. The tongue and groove joint 12, 26 is 
spaced below the top of the guide beam 4, 18. The reference character d in 
FIG. 2 represents the distance by which the top surface of the top of the 
guide beam 4, 18 is spaced from the joint 12, 26. In accordance with the 
invention, the spacing is provided in order to isolate the joint 12, 26 
from the top of the guide beam 4, 18 and from a bearing positioned on the 
guide beam 4, 18. 
The inner walls 10, 24 preferably extend downwardly and laterally outwardly 
toward each other and away from their respective sidewalls 6, 20, as shown 
in FIG. 2. However, this configuration may be varied without departing 
from the spirit and scope of the invention. For example, the inner walls 
could be vertical with no angling toward each other. Whatever the specific 
orientation of the inner walls, the inner walls together define an 
upwardly opening space above the tongue and groove joint. Referring to 
FIG. 2, the inner walls 10, 24 together define a V-shaped space 46 
therebetween. 
In the embodiment shown in Figs. 1-6, the tongue and groove joint 12, 26 
provides vertical clearance V and lateral clearance L between the groove 
portion 12 and the tongue 26. This permits relative vertical and lateral 
movement between adjacent base sections 2. Such relative movement allows 
for adjustment of the positions of adjacent base sections 2 during the 
installation of the conveyor and the assembly of the base sections 2 into 
a base structure for the conveyor. It also allows for relative movement to 
accommodate, for example, thermal expansion following installation and 
during use of the conveyor in situations in which the joint is either not 
sealed or is sealed by a flexible sealant. The joint is preferably sealed 
to help achieve the goal of a leakproof base structure for the conveyor. 
The tongue 26 and groove portion 12 forming the joint together define a 
sealing space 29 for sealing the joint 12, 26. The outer end of the tongue 
26 has a projection 28 extending upwardly therefrom. The projection 28 
defines the laterally outer end of a slot formed along the tongue 26. This 
slot and the adjacent confronting wall of the groove portion 12 define the 
sealing space 29. 
Referring to FIG. 3, the sealing space 29 is configured to receive a 
sealing material 30 to seal the joint 12, 26. The sealing material 30 is 
preferably a flexible sealant, such as the sealant sold under the 
trademark SIKAFLEX. The sealant may be placed in the slot on the tongue 26 
and/or in the groove 14 prior to assembling the base sections 2 together. 
Alternatively, the sealant may be injected into the sealing space 29 
following positioning of the tongue 26 in the groove 14. In either case, 
the sealant preferably fills the sealing space 29 and the vertical and 
lateral clearances V, L formed between the tongue and groove portions 26, 
12, as shown in Fig. 3. Some of the sealant 30 also oozes up out of the 
sealing space 29 into the V-shaped upwardly opening space 46 formed 
between the inner walls 10, 24. Still referring to FIG. 3, it can be seen 
that the space 46 is large enough, and the distance d by which the joint 
12, 26 is spaced below the top surface of the guide beam 4, 18 is 
sufficient, to maintain the area above the vertical height defined by the 
upper surfaces of the top portions 8, 22 isolated from the sealant 30. The 
dimensioning also serves to isolate a bearing 50 placed on the guide beam 
4, 18 from the sealant 30. 
FIG. 4 illustrates an alternate means for sealing the joint 12, 26. 
Following the positioning of the tongue 26 in the groove 14 and the 
completion of the assembly of the base structure, the inner walls 10, 24 
may be welded together to secure the joint 12, 26. The welding procedure 
creates a weld bead 31 extending longitudinally above the tongue and 
groove portions 26, 12 in the V-shaped space 46. In order to help ensure 
that the joint 12, 26 is sealed, a thin layer of sealant 0 may be placed 
over the weld bead 31. When the sealing process has been completed, the 
area above the guide beam 4, 8 is isolated from both the weld bead 31 and 
the layer of sealant 30 to isolate the joint 12, 26, as described above. 
Referring to FIGS. 1, 5, each intermediate guide beam 36 includes a pair of 
opposite vertical walls 38, 40 joined to the lower walls 32, 34, 
respectively, of the base section 2 at a curved interface. A top portion 
42 that forms part of the top of the guide beam 36 extends horizontally 
from the top of each vertical wall 38, 40. The top of the guide beam 36 is 
open between the top portions 42. The bottom of the guide beam 36 is 
closed by a bottom wall 44. The top of the guide beam could also be 
closed, and the bottom could be open. However, the illustrated 
configuration is preferred since it permits the base section 2 to be 
riveted or otherwise secured to an underlying structure by securing the 
bottom wall 44 thereto. 
Each of the vertical walls 38, 40 and the sidewalls 6, 20 has a side edge 
portion 48 extending laterally outwardly therefrom opposite the 
corresponding top portion 42, 8, 22. For each guide beam 4, 18 and 36, the 
opposite side edge portions 48 provide a means by which a bearing 50 
engages the beam 4, 18, 36. The preferred configuration of the bearing 50 
is best seen in FIG. 2. Each bearing 50 has a top portion 52, a first side 
channel portion 54, a second side channel portion 56, a cam portion 58, 
and first and second lock flanges 60, 62. Each lock flange 60, 62 includes 
a lower edge portion in the form of a circular bead 64. The structure of 
the bearing 50 and the manner in which it is installed on and engages the 
guide beam 4, 18, 36 is described further in my U.S. Pat. No. 4,238,360. 
The portion of that patent relating thereto is incorporated herein by 
reference. 
The guide beams 4, 18, 36 support the bearings 50, which in turn support 
longitudinal floor members 68. The floor members may take various 
configurations. The illustrated configuration of the floor members 68 is 
similar to the configuration shown in my aforementioned U.S. Pat. No. 
5,238,360 with the exceptions that the floor member 68 is narrower and 
lacks the inside walls 116,118 shown in the floor member 10 in the patent. 
In addition, each guide beam 4, 18, 36 is provided with its own individual 
floor member 68. This results in there being a liquid collecting channel 
CH between each pair of adjacent guide beams 4, 18, 36. 
FIGS. 5 and 6 illustrate portions of a reciprocating floor conveyor 
incorporating the base section 2 and improved connection of the invention. 
The floor members 68 are moved longitudinally in one direction to convey a 
load and are retracted in the opposite direction, in a known manner. Each 
floor section is supported by a plurality of bearings 50. Adjacent 
bearings 50 are spaced longitudinally apart a small amount, for example 
about one-half inch, in order to allow for thermal expansion of the 
bearings. For the same reason, each bearing 50 is secured to the 
underlying guide beam 4, 18, 36 by rivets 72 only on one end of the 
bearing 50. 
At the discharge end of the conveyor (e.g. the rear of a trailer), 
represented by the line 74 in FIG. 6, the bearings 50 terminate inwardly 
of the end 74. Between the outermost bearing 50 and the end 74, a wear 
strip 70 is secured to the underlying guide beam 4, 18, 36 by rivets 72. 
As can be seen best in FIG. 6, the wear strip 70 is essentially the same 
width as the guide beam 4, 18, 36 and is narrower than the bearing 50. The 
strip 70 is spaced longitudinally from the adjacent bearing 50 for the 
same reason that adjacent bearings 50 are spaced from each other. The wear 
strips 70 function as stops for the bearings 50. The wear strips 70 are 
preferably made from a plastic material that is highly wear resistant. One 
example is the nylon and molybdenum disulphide material sold under the 
trademark NYLATRON. The bearings 50 are preferably made from a 
self-lubricating plastic, such as polyethylene. 
FIGS. 7 and 8 are similar to FIGS. 1 and 2 except that they show a modified 
form of the base section 102. Elements in FIGS. 7 and 8 that are the same 
as the elements shown in FIGS. 1-6 are given the same reference numerals 
as in FIGS. 1-6. Referring to FIGS. 7 and 8, the difference between the 
two embodiments is found in the details of the structure of the tongue and 
groove joint 126, 112. The first side portion 104 of the base section 102 
has a sidewall 6, a top portion 108 extending laterally from the top of 
the sidewall 6, and an angled inner wall 110 extending downwardly from the 
outer end of the top portion 108. A groove portion 112 of the tongue and 
groove joint is carried by the lower end of the angled wall 110. The 
second side portion 118 includes a sidewall 20, a top portion 122, and an 
angled inner wall 124. The lower end of the angled wall 124 carries a 
tongue 126 that is received into the groove 114 formed by the groove 
portion 112 of the adjacent first side portion 104. As in the embodiment 
shown in Figs. 1-6, the tongue and groove portions 126, 112 together 
define a sealing space 129. The difference in the joint is that the tongue 
126 and the groove 114 are shorter than the corresponding elements 26, 14 
in the first embodiment. As a result, there is little, if any, vertical 
and lateral clearance between the tongue and groove portions 126, 112. 
Above the joint 112, 126, there is an upwardly opening V-shaped space 146. 
This space 146 functions in the same manner as the space 46 provided by 
the embodiment shown in FIGS. 1-6. 
In reciprocating floor conveyors including the improved connection of the 
invention, the tongue and groove joint between base sections is isolated 
from the top of the guide beam formed by the side portions of adjacent 
base sections and from a bearing having a top portion that sets down on 
top of the guide beam. The dimensioning of the spacing of the tongue and 
groove joint and the upwardly opening space above the joint allows the 
joint to be sealed while maintaining the joint, including sealing portions 
thereof, isolated from the top of the guide beam and the bearing. As 
illustrated in FIGS. 3 and 4 and described above, this prevents contact 
between the bearing and sealant 30 that may enter the space above the 
joint. The bearing is protected from contamination by the sealant, and 
sticking of the bearing to the guide beam caused by the sealant is 
avoided. With regard to the weld bead 31 illustrated in FIG. 4, the 
isolation of the joint helps simplify the installation procedure of the 
base structure of the conveyor. Since there is ample space above the joint 
and below the bearing, there is no need to sand down the weld bead 31 to 
ensure that it does not contact the bearing. 
Although the preferred embodiments of the invention have ben illustrated 
and described herein, it is intended to be understood by those skilled in 
the art that various modifications and omissions in form and detail may be 
made without departing from the spirit and scope of the invention as 
defined by the following claims.