Endwise pushdown guide and lateral restraint fitting for cargo

An endwise pushdown guide and lateral restraint fitting for cargo having a base adapted to be secured to an aircraft subfloor. The base supports to a pair of parallel pivot pins and pivotally secured on each pin is a respective blade normally extending in an upright position. Each blade is supported by a pair of lugs through which a respective pivot pin extends, the pin for each blade being remote therefrom to provide a moment arm from the pivot to the blade. The blades are parallel and have respective ramp surfaces, tapering toward the direction from which cargo may be moved along an aircraft floor. Thus, when a cargo container is moved against one tapering surface the horizontal force thereof has a downward component which acts on the tapering surface and the moment arm of that blade to cause the blade to pivot downwardly under the container so that it can be moved past what would otherwise be a restricting blade, the blades being adapted to restrict cargo on their lateral surfaces outwardly of the supporting base and pivots.

BACKGROUND OF THE INVENTION 
Cargo containers of three or more widths are typically received in cargo 
compartments of aircraft. Because the containers have different base 
widths, it is necessary to provide sidewise guidance and restraint 
fittings for the various widths, three for example. 
This could be accomplished by using movable, adjustable, or controllable 
guide/restraint fittings. However, all three of the foregoing techniques 
involve unacceptable penalties in terms of cost, complication, manpower, 
and handling time requirements; and weight, in various combinations of the 
foregoing. 
SUMMARY OF THE INVENTION 
The present invention solves the foregoing problems by the provision of 
sidewise guidance/restraint fittings which accommodate three or more 
container base widths. The guidance/restraint fittings are completely 
passive in that they do not obstruct the loading or unloading of 
containers regardless of size. The cargo spaces have fixed guides on 
opposite sides thereof and a multiple series of rollers between on which 
the cargo containers are moved in and out. 
Two or more rows of restraint fittings are positioned in the subfloor 
according to the size of the container widths to be loaded. The rows of 
restraint fittings are centrally positioned and laterally spaced in 
accordance with the size of the containers that they are to guide on 
loading and unloading and restrain against lateral movement while they are 
in the cargo space. 
The individual pushdown guide and restraint fittings have two upwardly 
extending blades which are removably extended or secured in the upward 
position by means of a torsion spring. Containers of a particular size are 
moved between one of the rows of restraint fittings and the fixed guide 
rails at the side, or between the fixed side rails if wide enough. When 
the containers are wide enough so as to extend over one row of fittings, 
to be guided and restrained by another row, they are moved onto the row in 
the way thereof, the fittings being collapsed when the containers make 
contact therewith. That is, the containers rotate the upwardly extending 
blades, held by the spring, downwardly toward the floor under the 
container by the action on a moment arm between each blade and its 
supporting pivot. 
Each blade has a tapered top ramp surface which extends toward a container 
moving thereagainst and the container force has a downward component which 
moves against the blade and acts on the moment arm to pivot the blade 
downwardly below the bottom of the container and out of the way, to permit 
the container to move thereover. 
Accordingly, it is an object of the invention to provide an improved 
endwise pushdown guide and lateral restraint fitting for use in a cargo 
compartment in which the containers have various predetermined widths. The 
containers are guided as they are moved fore and aft within the aircraft 
and restrained laterally by the fittings against which they fit. 
It is another object of the invention to provide a guide and restraint 
fitting over which a container will easily move by making endwise contact 
with the blades of the fitting and folding them sidewise to a position 
below the level of the container. The fundamental characteristics of the 
guide and restraint fittings, according to the invention, are that they 
resist forces applied laterally and fold down easily in response to 
endwise contact by an approaching container base. 
Further objects and advantages of the invention may be brought out in the 
following part of the specification wherein small details have been 
described for the competence of disclosure, without intending to limit the 
scope of the invention which is set forth in the appended claims.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring again to the drawings, there are shown in FIG. 1 three rows of 
endwise pushdown guide and lateral restraint fittings, generally 
designated as 10, installed in the lower lobe or subfloor 12 of an 
aircraft cargo compartment 14. The fittings 10 are installed in parallel 
rows and extend above the cargo support level which is defined by rails 16 
and 18, support members 20 and 22 which support rollers 24 extending 
upwardly therefrom and on which the cargo is rolled inwardly and outwardly 
of the compartment. Support rails 26 and 28 at the outer edges are at the 
same level of the rails 16 and 18. At the outer edges are fixed guide and 
restraint rails 30 and 32. 
Containers to be stored in the cargo compartment 14 are of predetermined 
widths, such as the largest being those restrained between the rails 30 
and 32, and the others being of widths that are stored and laterally 
restrained between one of the rails 30 and 32 and any of the three rows of 
the fittings 10. 
As shown in FIGS. 2-6, the fittings are comprised of a base member, 
generally designated as 40, having a bottom plate 42 and four screw holes 
44 extending therethrough to receive screws 46 to secure the base to the 
subfloor 12. Extending upwardly from the base 42 are two parallel support 
members 48 and 50, FIG. 3. The member 48 has a pair of bores 52 and 54 
having parallel centerlines and similarly, the member 50 has a pair of 
bores 56 and 58 having parallel centerlines, the bores 52 and 56 being in 
axial alignment and the bores 54 and 58 being in axial alignment, FIGS. 3 
and 5. The bores 54 and 58 are adapted to support pivot pin 60 and the 
bores 52 and 56 are adapted to support pivot pin 62. The pins 60 and 62 
each have a threaded, small diameter end 64 and 66, respectively. The pin 
62 extends through bores 70 and 72 in lugs 74 and 76 which support a blade 
80. Similarly, the pin 60 extends through the bores 82 and 84 in lugs 86 
and 88, respectively, which support blade 90. 
The pivot pin 62 is rotatable in the bores 52 and 56. It is fixed to rotate 
with the blade 80, being threadedly engaged in the tapped bore 72 through 
which it extends to receive a nut 92 to secure the pin and blade to the 
support 40. Similarly, the pin 60 is rotatable in the bores 54 and 58 and 
is fixed within the bores 82 and 84, being threadedly engaged in the 
latter and secured to the support by means of a nut 94. 
The unthreaded end of the pin 62 fits loosely in a recess 100 in the lug 
88. Similarly, the unthreaded end of the pin 60 fits loosely in a recess 
102 in the lug 76, FIGS. 2 and 3. As may be seen in FIGS. 2-4 and 6, a 
coil spring 106 extends around the parallel pins 60 and 62 and between the 
lugs 74 an 86. The spring has its ends 108 and 110 engaged in bores 112 
and 114 in the lugs 76 and 86, respectively. The spring 106, therefore, 
functions to hold the blades 80 and 90 in a biased upright position. 
The lugs 74 and 86 have cutaway portions 120 and 122, respectively, FIG. 3, 
the lower surfaces of which engage pins 60 and 62, respectively. When the 
blades are in the upright position, the pins and the cutaway portions act 
as a stop against the force of the spring and limit the upward movement of 
the blades and support the blades against the lateral forces of the cargo. 
The blades 80 and 90 have an upper central portion 126 and 128, 
respectively, and have tapering ramp surfaces 130, 132, and 134, 136 on 
their respective forward and rearward ends. The blades are laterally 
offset at their ends, FIG. 5, as at 140, 142, 144 and 146, toward each 
other, and similarly at 150, 152, 154 and 156 so that cargo not precisely 
aligned, hitting a surface such as 140 will be guided onto a surface 150 
and generally in the direction of that side of the blade into the desired 
path. Similarly, if a container makes contact with the surface 142, it 
then makes contact thereafter with the surface 152. 
The spacing of each pivot pin from the bottom of the blade provides a 
moment arm, between the arrows as at 160 and 162, FIG. 3. Thus, when a 
container as 166, FIGS. 2 and 6, has a width which causes it to move 
against a tapered portion as 130 of a blade, the downward component 170 of 
the horizontal force 172 of the container acts on the moment arm, as 160, 
to rotate the blade downwardly against the force of the spring 106 to a 
position under the container, FIG. 6, which is spaced above support 
members as 22 and 18 by the rollers 24 to permit the container to move 
over the blades of the fittings 10. 
That is, when a blade is contacted endwise by a container its downward 
force component is generated at the point of contact on the ramp portion. 
This downward component acts around the offset pivot point to generate the 
moment which overcomes the return spring torque and deflects the blade out 
of the way of the oncoming container. 
As indicated in FIG. 6 if the container had been in position to move 
endwise over both of the blades, the blade 90 would have been moved 
downwardly below the surface 22 toward the left side of the drawing. As a 
container moves endwise along the row of fittings 10, all of the blades 
are rotated downwardly out of the way of the container, the blades being 
folded sidewise as a result of the endwise contact acting on the moment 
arms, as 160 and 162. 
One blade can be removed from a row of fittings if they are required to 
guide and restrain on one side only. The outer distal sides of the blade, 
with respect to the torsion springs, restrain the cargo containers 
laterally, along with the rails 30 and 32 or blades of possibly another 
row of fittings 10. 
The invention and its attendant advantages will be understood from the 
foregoing description and it will be apparent that various changes may be 
made in the form, construction, and arrangements of the parts of the 
invention without departing from the scope and spirit thereof or 
sacrificing its material advantages, the arrangements hereinbefore 
described being merely by way of example. I do not wish to be restricted 
to the specific forms shown or uses mentioned except as defined in the 
accompanying claims.