Ball block for mounting linear motor

The ball end (16) of the piston rod (14) of a linear motor (6) is mounted in a ball block (52). The block (52) has mating housing portions (54, 56) that abut along mating surfaces (64) that are substantially parallel to, but slope relative to, the motor axis (X). One housing portion includes an integral rear wall (70) through which the axis (X) extends and which defines a portion of a socket (58) that receives the ball end (16). The other housing portion has a flange (78) that projects into a space between the socket (58) and a sloping extension (74) of the wall (70). The outer surface (76) of the wall (70) is secured to a fixed support (84). The wall (70) transmits loads carried by operation of the motor (6) from the ball end (16) directly to the support (84) and minimizes loads on the fasteners (68) securing the housing portions (54, 56) together. The housing portion that includes the wall (70) is made from a material with a high load carrying capability. The other portion is relatively easy to machine and includes a passageway to deliver fluid to the ball end (16). A reinforcing bar (150) extends rearwardly from the motor (6) through a channel formed by a floor member of a reciprocating floor conveyor.

TECHNICAL FIELD 
This invention relates to mountings and connections for linear motors and, 
more particularly, to a ball block that receives a ball end of a motor and 
has a rear wall through which the motor axis extends and which directly 
transmits loads created by operation of the motor from the ball end to a 
fixed support to which the wall is secured, and to a reinforcing bar that 
extends forwardly from the motor to attach it to a reciprocating floor 
member and reinforce the floor member. 
BACKGROUND INFORMATION 
Linear motors of the type including a piston component and a cylinder 
component are used in a wide variety of installations. The motors may be 
powered hydraulically, pneumatically, electrically, or by other suitable 
means. In a typical installation, one of the piston and cylinder 
components is connected to a structure to be moved by the motor, and the 
other component is mounted to a fixed support. Since minor misalignments 
between the motor axis and the structure being moved are frequently 
difficult to avoid, it is sometimes desirable to mount the motor in a 
manner that allows some lateral movement to correct for minor 
misalignments. One way of accomplishing this is to provide the motor 
component which is to be mounted with a ball end and to mount the ball end 
in a socket formed by a ball block, which is in turn secured to a fixed 
support. In order to permit assembly of the ball end in the ball block, 
the block of necessity must be more than one piece, and the division 
between the pieces must extend through the socket. A problem that can 
arise from the division of the ball block into pieces is the load imposed 
on fasteners holding the ball block pieces together when the motor is 
operating. 
DISCLOSURE OF THE INVENTION 
The present invention is directed toward improved mountings and connections 
for linear motors. An aspect of the invention is directed more 
specifically toward a ball block for mounting a ball end of a linear motor 
which has a piston component and a cylinder component. The ball end is 
formed on an outer end of one of these two components. The motor is 
operable to move the components relative to each other along an axis that 
extends through a center portion of the ball end. According to this aspect 
of the invention, the ball block comprises first and second mating housing 
portions that together define a socket for receiving the ball end. The 
housing portions abut each other along mating surfaces that are 
substantially parallel to the axis. The socket has a closed rear end 
portion, and a forward end portion. A passageway extends from the forward 
end portion through the first and second housing portions. The passageway 
is dimensioned to receive therethrough a forwardly projecting portion of 
the component on which the ball end is formed. A plurality of fasteners 
are positioned around the socket and extend through the mating surfaces to 
secure the housing portions together. One of the housing portions includes 
an integral rear wall. The wall has an inner forward surface that defines 
a rear portion of the socket, and an outer rear surface that is securable 
to a fixed support. The axis extends through the rear surface and the 
forward surface, and the wall extends substantially perpendicularly past 
the axis, to directly transmit loads created by operation of the linear 
motor from the ball end to a fixed support to which the wall is secured. 
The ball block of the invention solves the problem discussed above of 
operational loads on fasteners by providing for the direct transmission of 
operational loads from the end of the motor component to a fixed support. 
The direct transmission of the loads by an integral housing wall 
alleviates and helps minimize the loads on the fasteners that hold the two 
housing portions together. The invention accomplishes the efficient 
transmission of the operational loads while maintaining structural 
simplicity and ease of assembly and disassembly. The result is a highly 
reliable and cost effective mounting for a linear motor that may be used 
in a variety of situations. 
In addition to the basic features described above, the ball block may 
include any one of a number of preferred features, or some combination of 
such features. One such preferred feature is mating surfaces of the 
housing portions that slope toward the axis from the rear wall to the 
passageway. This sloping configuration facilitates assembly of the ball 
end in the socket while helping to maximize the effectiveness of the rear 
wall as a transmitter of loads. Another preferred feature is a flange that 
cooperates with the rear wall to define the socket. In ball blocks having 
this feature, the inner rear surface of the forward wall extends 
definingly around the socket past the axis and then slopes away from the 
socket to define a space between the socket and the forward surface. The 
other housing portion includes the flange, which projects into the space 
to cooperate with the forward surface in defining the socket. This feature 
also facilitates assembly of the ball end in the socket and increases the 
efficiency of the rear wall. When provided in combination, the features of 
the sloping mating surfaces and the flange enhance each other to help 
maximize these advantages. 
The two housing portions of the ball block may be made from various 
materials. Since the transmission of operational loads is accomplished at 
least primarily by the portion on which the rear wall is formed, in 
general the other housing portion need not have as high a load carrying 
capability as the portion including the rear wall. According to an aspect 
of the invention, the housing portion including the rear wall is made from 
a first material, and the other housing portion is made from a second 
material. The first material has higher load carrying capability than the 
second material. The second material is more easily machined than the 
first material. The ball block further comprises at least one passageway 
in the other housing portion for delivering fluid pressure to the ball 
end. This aspect of the invention adds further to the cost effectiveness 
of the design by increasing the ease of manufacture of the ball block 
while retaining its desirable load carrying capabilities. 
According to another aspect of the invention, the ball block described 
above is provided in a reciprocating floor conveyor in combination with a 
plurality of floor members and a linear motor. The motor includes a piston 
component, a cylinder component, a rear ball end, and an opposite rear end 
that is attached to one of the floor members. The motor is operable to 
move the components relative to each other along an axis that extends 
through a center portion of the ball end. The combination preferably 
further comprises a guide beam that is secured to an upper portion of the 
outer rear surface of the ball block and projects rearwardly therefrom to 
extend above the fixed support and guide movement of the floor member that 
is attached to the motor. In a preferred arrangement, the floor member 
attached to the motor includes a top portion and opposite side portions 
defining a downwardly opening channel. The combination comprises a housing 
that defines a socket into which the forward end of the motor is received, 
and a connector extending forwardly from the housing. The connector is 
received into the channel defined by the floor member and is attached to 
the top portion. 
It is anticipated that a typical reciprocating floor conveyor incorporating 
the combination of the invention described above will include a plurality 
of floor members that are divided into sets and groups, with each group 
including at least two adjacent independent floor members and each set 
including one floor member from each group. The conveyor includes a 
plurality of motors, one for each set of floor members. The forward end of 
each motor is attached to one of the floor members in its corresponding 
set of floor members. It is attached by means of a connector that extends 
forwardly through a channel, as described above. The conveyor further 
comprises a plurality of transverse drive beams, one for each set of floor 
members. Each drive beam is attached to, and positioned below, each floor 
member of its set of floor members. 
A preferred feature of the combination is a reinforcing bar that is 
attached to and extends forwardly from the forward end of each motor. The 
bar is received into the channel of the corresponding floor member and is 
attached to its top portion to reinforce the floor member. The reinforcing 
bar may extend forwardly from a housing that receives the forward end of 
the motor. Preferably, the reinforcing bar extends through the channel 
above the transverse drive beam for the corresponding set of floor members 
and is secured to the drive beam. In the preferred embodiment, the 
combination includes transverse drive beams that are spaced longitudinally 
along the floor members, and each reinforcing bar extends through its 
corresponding channel above each transverse drive beam. This arrangement 
allows the longitudinal spacing of the drive beams to balance the loads on 
the floor members. It also permits the use of relatively lightweight floor 
members to reduce the overall weight of the conveyor. 
Another aspect of the invention is directed to the combination, in a 
reciprocating floor conveyor, of a plurality of floor members, a plurality 
of linear motors, a plurality of reinforcing bars, and a plurality of 
transverse drive beams. The floor members are divided into sets and 
groups, as described above. There is a linear motor for each set of floor 
members, and each motor includes a rear end attached to a fixed support 
and an opposite forward end attached to one of the floor members in the 
corresponding set. The floor members to which the motors are attached have 
the channel configuration described above. A reinforcing bar is attached 
to and extends forwardly from the forward end of each motor. The bar is 
received into the channel of the corresponding floor member and is 
attached to the top portion thereof to reinforce the floor member. There 
is a transverse beam for each set of floor members. Each drive beam is 
positioned below each floor member of its set and is attached to and 
positioned below the reinforcing bar for its set. The combination may 
further comprise one or more preferred features, such as the guide beams, 
ball block, housing for the forward end of the motor, and elongated 
reinforcing bars described above. When guide beams are included, each 
guide beam preferably carries a bearing to support sliding movement of the 
floor member relative to the guide beam. The transverse drive beams also 
preferably carry bearings. The bearings are positioned between each drive 
beam and each reinforcing bar that extends above and is movable relative 
thereto. Alternatively, the transverse drive beams may be spaced below the 
reinforcing bars that are movable relative thereto. 
These and other advantages and features will become apparent from the 
detailed description of the best modes for carrying out the invention that 
follows.

BEST MODES FOR CARRYING OUT THE INVENTION 
The drawings show a ball block 52 that is constructed in accordance with 
the invention and that also constitutes the best mode of the ball block 
currently known to the applicant. In the drawings, the ball block 52 is 
shown mounting the ball end 16 of the piston component 12 of a hydraulic 
linear motor 6. The drawings also illustrate three motors 6 mounted by the 
ball block of the invention as part of a reciprocating floor conveyor. It 
is anticipated that the primary use of the ball block of the invention 
will be in this type of installation. However, it is of course to be 
understood that the ball block of the invention could also be used to 
advantage in a wide variety of other types of installations. The ball 
block of the invention may also be used to mount non-hydraulic linear 
motors and/or to mount the cylinder component of a linear motor. 
The structure of the preferred embodiment of the ball block of the 
invention can best be seen in FIGS. 3-13. The ball block 52 includes first 
and second mating housing portions 54, 56. In the assembled block 52, the 
housing portions 54, 56 abut each other along mating surfaces 64. As 
shown, these mating surfaces 64 are substantially parallel to the axis X 
of the linear motor 6 mounted by the block 52, i.e., although they may 
slope relative to the axis X, their orientation is predominantly parallel, 
as opposed to perpendicular, to the axis X. The mating surfaces could also 
be stepped instead of, or in addition to, being sloped relative to the 
axis X. The two housing portions 54, 56 together define a socket 58 for 
receiving the ball end 16 of the piston component 12. The socket 58 has a 
closed rear end portion, and a forward end portion. The rearward direction 
is indicated by the arrow in FIG. 3. A passageway 60 extends from the 
forward end portion of the socket 58 through the first and second housing 
portions 54, 56. The passageway 60 is dimensioned to receive therethrough 
the piston rod 14. The rod 14 has the ball end 16 formed thereon and 
projects forwardly from the ball end 16 out from the ball block 52. A 
plurality of fasteners 68 extend through holes 66 in the housing portions 
54, 56 to secure the housing portions 54, 56 together. In the illustrated 
embodiment, there are four fasteners 68 positioned symmetrically around 
the socket 58 and extending through the mating surfaces 64. 
The passageway 60 has an annular groove 63 formed thereon for receiving an 
annular seal 62. The seal 62 engages the piston rod 14 to prevent 
contaminants from entering the ball block 52 through the passageway 60. 
The seal 62 has sufficient resiliency to allow slight lateral displacement 
of the piston rod 14 in the passageway 60 to correct for minor 
misalignments between the ball block 52 and the linear motor 6 without 
allowing actual metal-to-metal contact between the motor 6 and the block 
52. 
As shown, the first housing portion is an upper portion 54, and the second 
housing portion is a lower portion 56. It is anticipated that the ball 
block of the invention will be used primarily in this orientation. 
However, the ball block could also be used in other orientations. For 
example, the first portion could be below, laterally adjacent to, or 
angled with respect to the second portion. 
In the illustrated preferred embodiment, the upper housing portion 54 
includes an integral rear wall 70. Referring to FIG. 10, the wall 70 has 
an inner forward surface 72 and an outer rear surface 76. The inner 
surface 72 defines a rear portion of the socket 58. The outer surface 76 
is securable to a fixed support. The securing of the wall 70 to the 
support may be accomplished by various means, such as by welding 86, as 
illustrated in FIGS. 5 and 6. Still referring to FIG. 10, the rear wall 70 
extends substantially perpendicularly downwardly past the motor axis X. 
The axis X extends through the wall 70 and its inner and outer surfaces 
72, 76. This arrangement results in the direct transmission of loads 
created by operation of the linear motor 6 from the ball end 16 of the 
piston component 12 to a fixed support to which the wall 70 is secured. 
The loads are transmitted directly through the wall 70, which carries most 
of the load imposed on the ball block 52 to minimize loads on the 
fasteners 68. 
As noted above, the mating surfaces 64 may slope relative to the motor axis 
X, In the illustrated preferred embodiment, the mating surfaces 64 slope 
toward the axis X from the rear end of the block 52 to the forward end of 
the passageway 60, as best seen in FIGS. 5 and 8. This sloping mating 
surface feature is preferably provided in combination with the feature of 
a flange 78 formed on the lower housing portion 56. The inner forward 
surface 72 of the rear wall 70 of the upper housing portion 54 extends 
definingly around the socket 58 downwardly past the axis X and then slopes 
away from the socket 58 to define a space between the socket 58 and the 
forward surface 72. The flange 78 formed on the lower housing portion 56 
projects into this space to cooperate with the forward surface 72 in 
defining the socket 58. The shape of the flange 78 can best be seen in 
FIG. 3. The flange 78 extends around the socket 58 and upwardly into the 
space formed by the rear wall 70. The flange 78 is annular except for an 
interruption where the passageway 60 extends through the lower housing 
portion 56. The mating surfaces 64 extend around the flange 78 along the 
rear portion of the block 52 and from the rear edge to the rear edge of 
the block 52. The flange 78 carries shear loads and reinforces the rear 
wall 70. 
The combination of the sloping mating surfaces 64 and the flange 78 on the 
lower housing portion 56 facilitates assembly of the ball end 16 in the 
block 52 while maintaining efficient direct transmission of operational 
forces to a fixed structure. The sloping mating surfaces 64 allow the 
outer surface 76 of the rear wall 70 to project downwardly well beyond the 
motor axis X, and the forward edge of the mating surfaces 64 to be 
relatively close to the axis X. The relative closeness of the passageway 
division to the axis X allows the piston rod 14 to be easily positioned in 
the passageway 60 when the housing portions 54, 56, are moved together. 
The relatively large surface area of the outer surface 76 of the rear wall 
70 which may be welded to a fixed structure enhances the force 
transmitting function of the wall 70. The increased securing surface 76 
does not inhibit assembly of the block 52 with a motor because of the 
provision of the flange 78 on the lower housing portion 56 and the 
complementary sloping extension 74 on the rear wall 70 of the upper 
housing portion 52. The ball end 16 of the piston component 12 moves 
easily into the socket 58 as the housing portions 54, 56 are moved 
together because the top of the flange 78 and the beginning of the sloping 
extension 74 are both near the axis X. 
FIG. 1 illustrates an example of a type of reciprocating floor conveyor 
into which the ball block of the invention may be incorporated. This type 
of conveyor is described in the applicant's U.S. Pat. Nos. 5,165,524 and 
5,193,661, issued Nov. 24, 1992, and Mar. 16, 1993, respectively. The 
disclosures of these two patents are hereby incorporated into this 
application by reference. The conveyor will only be briefly described 
herein. Referring to FIG. 1, the conveyor includes a plurality of floor 
members 2 that are divided into sets and groups. There are three sets and 
a plurality of groups. Each group includes three adjacent floor members, 
one from each set. The three floor members 2 in each group are moved 
together and then are retracted sequentially to move a load supported by 
the floor members 2. The movement of the floor members 2 is accomplished 
by means of three linear motors 6. Each motor 6 includes a cylinder 
component 8 and a piston component 12. The motor 6 is operated to move the 
cylinder 8 relative to the piston 12 along the motor axis X. FIG. 1 shows 
one group of floor members 2. Each floor member 2 in the group is 
connected to its counterparts in the other groups by a transverse drive 
beam 4. Each of the floor members 2 shown in FIG. 1 is also secured to the 
movable cylinder component 8 of the corresponding motor 6. Referring to 
FIGS. 1, 2, and 5, the cylinder component 8 has an end member 10 which is 
received in a socket formed by a two-part housing 44, 46. The two portions 
of the housing 44, 46 are secured together by fasteners 48. A connector 50 
extends forwardly from the upper housing 44 and is secured to the top 
portion of the corresponding floor member 2 by suitable fasteners. 
As shown in FIGS. 7-11, the piston component 12 of the motor 6 has a 
generalized passageway 80 extending through the piston rod 14 into the 
ball end 16 that is received into the ball block socket 58. This 
generalized passageway 80 is a representation of a fluid passage structure 
that has been simplified in order to facilitate illustration of the ball 
block structure in these figures. FIGS. 12 and 13 show the details of the 
passageway structure shown schematically by passageway 80 in FIGS. 7-11. 
Referring to FIGS. 12 and 13, the piston component 12 includes a piston 
head 18 formed on the end of the rod 14 opposite the ball end 16. A 
central passageway 20 extends through the rod 14 and the head 18. The 
central passageway 20 connects a port region 24 in the ball end 16 with an 
extension chamber 28. An annular passageway 22 surrounding the central 
passageway 20 connects a port region 26 in the ball end 16 with a 
retraction chamber 30. The lower housing portion 56 of the ball block 52 
has passageways 38, 40 which communicate with the port regions 24, 26, 
respectively. Communication of the passageways 38, 40 with hydraulic fluid 
pressure in hydraulic lines 36 is controlled by two check valves 32, 34. 
Each valve 32, 34 is connected to pressure and return by valve ports 39, 
41. The valve 32 is opened mechanically by retraction of the cylinder 8, 
which brings a projection carried by the cylinder 8 into contact with a 
control rod 33 projecting from the valve 32. The valve 34 has a control 
rod 35 that is engaged by a projection carried by the cylinder 8 when the 
cylinder 8 extends. The hydraulic lines and other components of the 
hydraulic system are housed in a manifold housing 42. The housing portions 
54, 56 and the manifold 42 are secured together by fasteners 68'. The 
manifold is omitted in FIGS. 2-11 in order to simplify illustration of the 
invention. 
In the type of installation shown in FIG. 1, there are three linear motors 
6 each of which is mounted by a ball block of the invention. Referring to 
FIGS. 2, 3, and 6, the three ball blocks are mounted together in a 
side-by-side abutting relation. The ball block 52 on each end has the 
configuration illustrated in FIGS. 7-11. The center ball block 52' has a 
modified configuration to accommodate the side-by-side mounting. In the 
modified ball block 52', the lower housing portion 56' is narrower than 
the lower housing portion 56 of the unmodified ball block 52. Otherwise, 
the three ball blocks 52, 52' are essentially identical. 
Each of FIGS. 1 and 6 shows the upper portions 54 of the three ball blocks 
52, 52' secured to a fixed support member 84. In addition, the adjacent 
upper housing portions 54 are secured to each other by welds 90 (FIG. 6). 
Two guide beams 88 are secured to and extend forwardly from the upper 
portion of the outer rear surface 76 of each of the upper housing portions 
54. A bearing member 82 (FIG. 1) is secured to the top of each upper 
housing portion 54. In the assembled reciprocating floor, the upper 
housing portions 54 of the ball blocks 52 extend upwardly into the 
downwardly directed channels of the floor members 2. The guide beams 80 
extend rearwardly above the fixed support member 84 and upwardly into the 
floor member channels to guide reciprocating movement of the floor members 
2. Each guide beam 88 preferably carries a bearing 89 (FIG. 5) to support 
sliding movement of the floor member 2. The bearing members 82 on the ball 
blocks 52 also support sliding movement of the floor members 2. The upper 
housing portions 54 have side recesses 55 to provide clearance for the 
downwardly extending sides of the floor member channels. The housing 
portions 54, 56 of the ball block 52 may be made from various materials 
and may be made from the same or different materials. In the preferred 
embodiment, the two portions are made from different materials to maximize 
the load carrying capability of the ball block 52 while increasing ease of 
manufacture. The upper portion 54 is made from a material, such as hard 
steel, that has a high load carrying capability. The lower portion is made 
from aluminum or some other metal which, although it does not have the 
strength of hard steel, is relatively easily machined. This allows 
passageways, such as passageways 38, 40, to be economically formed in the 
lower portion 56 and, at the same time, maximizes the strength of the 
load-carrying upper portion 54. 
FIGS. 14-18 show another type of reciprocating floor conveyor that is 
similar to the conveyor shown in FIG. 1 but incorporates additional 
preferred features of the invention. The conveyor shown in FIGS. 14-18 
includes the preferred embodiment of the ball block 52, which mounts three 
linear motors 6, as described above. The major difference between the two 
types of installations is the manner in which the forward ends of the 
motors 6 are secured to their respective floor members 2. The floor 
members 2 are arranged in sets and groups, as described above. The floor 
members are omitted from FIGS. 14, 15, and 18, and only one floor member 2 
is shown in phantom in FIG. 17, to facilitate illustration of the 
connecting arrangement. Referring to FIGS. 16 and 17, each floor member 2 
includes a top portion 94 and opposite side portions 96 that define a 
downwardly opening channel 98. The upper housing portions of the ball 
blocks 52 are received into these channels 98. Each ball block 52 has a 
single guide beam 188 projecting rearwardly therefrom which is also 
received into the channel 98 and guides and supports the floor member 2, 
as described above in relation to the guide beams 88 in the arrangement 
shown in FIGS. 1-5. 
Referring to FIG. 14, the conveyor comprises a frame that includes opposite 
side members 100, an end beam 120, and the support member 84 to which the 
ball blocks 52 are secured. A plurality of transverse beams 102 are 
longitudinally spaced between the end members 84, 120 and extend between 
the side beams 100. The conveyor frame is secured to a main frame beam 118 
of a structure, such as a trailer, in which the conveyor is installed, as 
shown in FIGS. 14-16. The ball block of the invention and the connections 
of the linear motors to the floor members described below are designed to 
transmit operational loads to the main frame beam 118 via the conveyor 
frame. 
In the installation shown in FIGS. 14-18, the connectors 50 shown in FIGS. 
1, 2, and 5 are replaced by reinforcing bars 150. There is a bar 150 
attached to and extending forwardly from the forward end of each motor 6. 
Like the connector 50, the bar 150 is received into the channel 98 of the 
corresponding floor member 2 and is attached to the top portion 94 of the 
floor member 2. The bar 150 is a solid member with a square cross section 
and serves to reinforce the floor member 2 to which it is attached, as 
well as to connect the motor 6 to the floor member 2. As can be seen in 
FIG. 15, the upper portion 144 of the housing that receives the forward 
end of the motor 6 is modified to accommodate the attachment of the 
reinforcing bar 150. In the conveyor shown in FIGS. 14-18, the transverse 
drive beams 104 also have a different structure than the transverse drive 
beams 4 shown in FIG. 1. Each transverse drive beam 104 has a channel 
configuration with a generally C-shaped cross section. 
The transverse drive beams 104 are spaced longitudinally along the floor 
members 2. Preferably, each reinforcing bar 150 extends through its 
corresponding channel 98 above each of the three transverse drive beams 
104. Each reinforcing bar 150 is attached to the transverse drive beam 104 
that corresponds to its set of floor members 2 and is movable relative to 
the other transverse drive beams 104. Each drive beam 104 is positioned 
below both each floor member 2 that it crosses and the three reinforcing 
bars 150. FIG. 18 illustrates the relationship between the reinforcing 
bars 150 and the middle transverse drive beam 104. As shown, only the 
middle bar 150 is attached to the drive beam 104. The attachment is 
accomplished by means of a mounting plate 108 that is secured to the drive 
beam 104 by fasteners 110. The bar 150 is welded, as shown by reference 
numeral 112, to the mounting plate 108. The other two bars 150 may either 
be spaced above the drive beam 104 or may be slidingly supported thereon 
by bearings, such as the type of plastic bearings 114 shown in FIG. 17. 
FIG. 17 illustrates the relationship between the reinforcing bars 150 and a 
transverse beam 102 of the conveyor frame. Each bar 150 is slidable across 
the beam 102 and is supported thereon by plastic bearings 114. FIG. 17 
also illustrates the attachment of one of the bars 150 to a floor member 
2. The bar 150 is secured to the top portion 94 of the floor member 2 by a 
countersunk fastener 126. FIG. 14 shows other locations 128 at which the 
bars 150 are fastened to the floor members 2. Still referring to FIG. 14, 
each of the transverse drive beams 104 is provided with mounting 
projections 124 for securing it to the floor members in its set other than 
the floor member to which the corresponding reinforcing bar 150 is 
secured. Guide beams 122 of various lengths are provided for guiding 
movement of these other floor members and the forward ends of the floor 
members to which the reinforcing bars 150 are attached. For each of these 
latter three floor members, the reinforcing bar 150 and guide beams 122, 
188 are aligned to accurately guide reciprocating movement of the floor 
members and thereby ensure smooth operation of the conveyor. They are also 
substantially aligned with the motor axis X to reduce operational loads on 
the conveyor. 
Although the preferred embodiment of the invention has been 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.