Device for handling heavy loads by distributing force

Mccann, R. J.

English

NASA Technical Reports Server

March 4, 1969 JAMES E. W E B B  3,430,909 ADMINISTRATOR OF THE NATIONAL AERONAUTICS 
A N D  SPACE ADMINISTRATION 
DEVICE FOR HANDLING HEAVY LOADS 
Filed Nov. 9, 1966 
IN VENTOR. 
ROBERT J. MC CANN 
BY 
y ; i z J d  8.9- 
ATTORNEYS 
https://ntrs.nasa.gov/search.jsp?R=19690018088 2020-03-16T18:45:41+00:00Z
1 
3,430,909 
DEVICE FOR HANDLING HEAVY LOADS 
James E. Webb, Adminiskator of the National Aero- 
nautics ani? Space Administration. with resaect to a61 
invention of gobert J. McCann, hiountaiain view, Calif. 5 
Piled Nov. 9, 1966, Ser. No. 593,604 
US. CI. 248-317 6 Claims 
Hnt. CI. P16m 1/00 
ABSTRACT OF "HE DISCLOSURE 
This invention teaches how to distribute a high con- 
centrated force over a large area of an object. It is par- 
ticularly useful where an object is to be raised and has 
a relatively' thin skin that can be easily damaged by a 
concentrated force. Essentially a connection, including a 
frame and a plurality of resilient pins, is provided be- 
tween the means applying the force and the object. The 
pins are supported by their ends by the frame, like sim- 
ple beams. The central portion of each pin is connected 
to the object. The concentrated force is applied to the 
frame. The idea is to transmit the concentrated force 
through the resilient pins so that each pin bends within 
its elastic limit when a precalculated load on it is reached. 
Knowing the force to be applied, the pins can be designed 
to  bend under a precalculated load. That is, as a pin 
bends, adjacent pins pick up the load to thus distribute 
the concentrated force over a larger area of the object. 
10 
15 
20 
25 
30 
The invention described herein was made in the per- 
formance of work under a NASA contract and is sub- 
ject to  the provisions of Section 305 of the National 
Aeronautics and Space Act of 1958, Public Law 85-568 
(72 Stat. 435; 42 USC 2457). 
This invention relates to a construction for distribut- 
ing a concentrated force over a large area. More par- 
ticularly, it relates to a connection used in lifting heavy 
objects that distributes the large concentrated lifting force 4o 
over a relatively large area of the object to be lifted. This 
is accomplished by utilizing a plurality of members in 
the oonnection that are constructed to  deflect within 
their elastic limit and distribute the force. 
35 
Background of the inwention 46 
One of the problems in handling and lifting a heavy 
object is the concentrated lifting force applied to the 
object. For example, assume a crane is to lift an object. 
50 
Generally, the crane's cable is connected to  the eye bolts 
on the 'object at one, two, or three support points. The 
crane then reels in the cable and raises the object. With 
this type of lifting arrangement, the cable's entire lifting 
force is concentrated at the one, two, or three support 
points provided on the object. 
Where the object is very heavy or has a thin skin, this 
lifting force, concentrated at  a few points, becomes ex- 
tremely great. This, in turn, makes it necessary to provide 
reinforcing structure on the object and at  its support 
points so they can withstand the large lifting force. This 60 
additional reinforcing structure, in turn, increases the 
weight of the object. Where the object to be lifted is, for 
example, a heavy rocket booster, this additional reinforc- 
ing structure weight may be critical to the chances for a 
successful mission. 65 
Another problem, after a heavy object has been lifted, 
is that additional shock loads may be imposed on the 
object during the handling and transporting of the object. 
For example, many large and heavy booster rockets 
must be transported from the manufacturing plant to the 70 
launch site. This may involve transporting the booster 
55 
over water, state highways, and on-site roads, thus the 
booster will be subjected to many different types of shock 
loads during handling. 
This additional shock loading, in turn, makes it nec- 
essary to provide even more reinforcing structure on the 
heavy object so it can withstand these contemplated 
loads. This additional reinforcing structure also adds to 
the weight of the object. As mentioned previously, excess 
weight can be critical in such things as a spacecraft. 
With the above problems in mind, it can be seen that 
if a connection can be provided at each support point that 
distributes these large concentrated lifting forces over a 
larger area of the object, this will decrease the per unit 
stress on the object. That is, assume for example, that a 
lifting force of 100 pounds is acting on an area of one 
square inch and is now made to cover an area of ten 
square inches. The lifting force per square inch would 
now be one tenth as large or only 10 pounds. This reduced 
lifting force per unit area will, in turn, permit elimination 
of the heavy reinforcing structure previously needed. 
Thus, one advantage of distributing a force over a 
large area of an object to be lifted, is that less reinforcing 
structure will be needed, and the object will weigh less. 
Another advantage is that the concentrated lifting force 
per unit area will be smaller and there will be less like- 
lihood of damaging the object. 
Summary of the invention 
A connection made as taught by this invention, as 
discussed hereinafter, is capable of distributing a con- 
centrated force over a relatively large area of an object. 
The above is accomplished, by the present invention, by 
utilizing a connection that includes a framework contain- 
ing a plurality of elongated flexible parallel pins that are 
interposed between the concentrated load or lifting force, 
and the object. Each pin is supported like a simple beam 
and designed so that it will flex, within its elastic limit. 
When a pin is subjected to a load greater than a predeter- 
mined amount, it is designed to  flex so that adjacent pins 
pick up the load. Thus, the lifting force will be distributed 
by the pins over a large area. 
En terms of structure, the framework includes an elon- 
gated inverted U-shaped support that may be connected 
to a hoist, such as a crane's lifting cable, for example. 
A plurality of pins are positioned between the legs of the 
U-shaped support with the ends of the pins carried by 
each leg of the U-shaped support. The pins are positioned 
parallel to each other and in the same plane, like teeth 
in a comb. The central portion of each pin is adapted 
to be connected to the object to be lifted. Each pin is 
made with a thick central portion that decreases in thick- 
ness towards its ends. The pins are made of a material 
that is selected to permit deflection under a predetermined 
load. 
The ends of the pins are thus supported by the legs 
of the inverted U-shaped support that is connected to 
the hoist, and their center portion is connected to  the 
object to be lifted, so as to carry the weight of the 
object. This construction permits each pin to deflect like 
a simple beam. To further facilitate this deflecting move- 
ment, it has been discovered that, if the support-opening 
receiving each end of the pin is counterbored to provide 
a minimum bearing area, this will further permit the pin 
to flex so as to transfer the lead to adjacent pins. 
As a contrast to the above, if the concentrated lifting 
force were applied through pins that 'were rigid, the con- 
centrated lifting force would act directly on the pins under 
the lifting force. The force would remain concentrated, 
and would not be transferred to adjacent pins. However, 
with flexible pins, after the Wing force reaches a prede- 
termined amount, the pins flex and distribute the lifting 
3,430,909 
3 4 
force to adjacent pins to distribute the lifting force over 
a large area. 
In view of the above, it is therefore an object of this 
invention to provide a device that will distribute a con- 
centrated force. 
It is another object of this invention to provide a mate- 
rial handling connection that can decrease the amount of 
reinforcing structure needed to protect an object being 
moved. 
Another object of this invention is to provide a con- 
nection for handling a heavy object that permits the 
object to be lighter in weight due to elimination of 
unnecessary reinforcing structure. 
Brief description of the drawings 
to  permit one pin to deflect relative to another pin. Pins 
12 taper from their central portion 32, toward their ends 
34, 34 to provide a tapered portion that permits the pin 
to more easily deflect under load. While support 10 is 
shown connected to cables 6 and support 8 is connected 
to object 2, it is pointed out that the positions of these 
supports can be reversed if desired. 
Referring to FIGS. 4 and 6, it has been discovered that 
pins 12 will deflect a greater amount under less load, if 
openings 28 and 30 in leg members 24, 26 are provided 
with counterbored openings 36. These openings provide 
a minimum bearing area engaging each end of pin 12. 
The following is an example of the load distribution 
that resulted where a known concentrated lifting force 
of 30,000 pounds was applied, through the connection of 
this invention to an object. with a lifting force of 30,000 Other objects and advantages will appear from the specifications and claims taken in conjunction with the pounds, supports and were made approximately 
drawings, wherein: 
the lifting connection; 
this invention, shown attached to the heavy object; 
of arrows 3-3 showing a pin of the connection; 
more clearly show the pin and its support; 
FIG. 5 is a sectional view of FIG. 4 taken in the direc- 
tion of arrows 5-§ showing a cross-section of a pin; 
FIG. 6 is a sectional view of FIG. 4 taken in the direc- 
tion of arrows 6-6 showing the end of a pin received 3o plate kg was made .38 inch in 
in the enlarged bore of the support member. 
ft. long. The supports were interconnected by twenty- 
inches apart, along the length of 
the supports. Flanges 14, 14 were connected to object 
by twenty-eight evenly spaced bolts (14 bolts On each 
side of the plate). 
Under the above conditions, tapered pins 12 were made 
of SAE 4340 steel to satisfy the calculated deflection and 
to 25 strength requirements. Each pin was made 7 inches long, 
having an outer diameter of .625 inch, tapering to .35 
inch at its smallest diameter; legs 24, 26 were .5 inch in 
thickness and the width of the openings 28, 30 support- 
ing the ends of the pins was .25 inch in length, while 
First, as background, it is pointed out that if a 30,000 
Description of the prefewed einbodii~zeirt pound force is applied to an eye bolt that has a cross 
Referring to the drawings, and more particularly io sectional areh of one square inch, the lifting force would 
FIG. 1, there is shown a heavy object that may be a rocket be 30,000 pounds per square inch. As contrast, with the 
booster 2, for example, that is to be lifted. Booster 2 35 above setup, and with the 30,000 pound force applied 
is shown with two connecting devices 4, 4 artached to at the center line 37 of load plate 18, it was determined 
its surface. A hoist, such as a crane (not shown) may that the load on booster 2 at center line 37 was approxi- 
have its cable 6 attached to connecting device 4 to raise mately 1800 pounds per square inch. At about 5 inches 
booster 2. It will be apparent that a large concentrated from the center line of the lifting force, it was approxi- 
lifting force P will be applied through the cables, due to 40 mately 1750 pounds per square inch; at about 10 inches 
the heavy weight of the booster now being supported at Erom the center line the lifting force was approximately 
only two points. 1600 pounds per square inch; at approximately 15 inches 
Referring now to FIGS. 2 and 3. There is shown an from the point of loading, the lifting force was approxi- 
enlarged view of a connecting device 4 of this invention. mately 1400 pounds per square inch, and at approximately 
It includes supports 8 and 10 that are connected together 45 25 inches from the point of load application, the load was 
by pins 12. Support 8 may be connected to the heavy approximately 800 pounds per square inch, with the load 
object such as booster 2. It includes flanges 14 that are gradually decreasing away from the center line. 
connected by means in the form of bolts 16 to booster 2. It can be seen, in view of the foregoing, that the 30,000 
Sufficient bolts 16 are used to make sure that the lifting pound load has been distributed over a large area, and 
force P, transferred to booster 2, can be distributed 50 that the load at specific points on the surface of the object 
throughout the length of connecting device 4. Flanges 14, has been reduced from a concentrated lifting force of 
in turn, are connected to a load plate 18 that extends 30,000 pounds to a maximum of 1800 pounds per square 
vertically and is substantially flat. It has a series of open- inch as the center line. Thus there is no longer any danger 
ings 20 equally spaced along its length. of the lifting force damaging the object or booster. 
Support 10 is connected to the means that applies the 55 In summary, this invention teaches how to construct a 
lifting force such as cable 6. Support 10 includes an oonnecting device 4 for handling a heavy object 2 SO 
elongated member 22 that may be an I beam having as to distribute a concentrated lifting force P, over a rela- 
spaced legs 24, 26 connected thereto. The I beam and tively large area of the object. The connection includes a 
legs form an inverted U-shaped channel. The lower por- plurality of tapered pins 12 that are positioned adjacent to 
tion of legs 24, 26 are positioned to receive plate 18 60 each other and supported like simple beams. Each of the 
between them and to overlap the top of plate 18. Refer- pins is designed to deflect within its elastic limits when the 
ring to FIG. 4, each leg 24 and 26 is also provided with force on the Pin exceeds a precalculated amount, so as to 
a series of spaced openings 28, 30 that will align with distribute the concentrated force to adjacent pin members. 
openings 20 in plate 18. Legs 24 and 26 and plate 18 As Will be apparent to those skilled in the art, the num- 
are interconnected by pins 12 that transmit the force 65 ber of lifting connection 4, number of pins 12, as well as 
the size of supports 8, 10, would depend on the contem- 
plated lifting load, the number of hoists used, and the from one support to the other support. 
Its central portion 32, and ends 34, 34 have a substan- 70 ing structure will operate just as well if an object were 
tially uniform diameter, SO that openings 20, 28 and 34 pushed through this construction, or if the lifting force 
can all be made the same diameter for convenience. were applied to axis of the object to be Iifted 
Ends 34, 34 are carried within leg openings 28 and 30, rather than normal to the axis as illustrated. 
and central portion 32 is received in opening 28 of load It will also be apparent to those skilled in the art that 
plate 18. The openings are slightly larger than the pins, 75 the terms “heavy” or “light” are relative. Where the ob- 
FIG. 1 is a view of a heavy object being lifted, showing 
FIG. 2 is an enlarged view of the lifting connection of 20 
FIG. 3 is an end view of FIG. 2 taken in the direction 
five pins 12, spaced 
is an view Of a portion Of 
Referring to 4, an view Of a pin l2 is allowable maximum load it is desired to allow in the ob- shown. Each Pin 12 is essentially an elongated cylinder. ject. AdditionaIly, lifting is illustrated, the connect- 
3,430,909 
5 6 
ject or load is ‘‘light,’’ even toothpicks could be used 
for pins 12, if the toothpicks are x e d  so they flex within 
their elastic limit to transfer the load to adjacent tooth- 
picks, as taught by this invention. 
Although but a single embodiment of the present in- 
vention has been illustrated and described, it will be ap- 
parent to one skilled in the art that various changes 
and modifications may be made therein without depart- 
ing from the spirit of the invention. 
2. A device, as set forth in claim 1, wherein said U- 
shaped support’s openings, that receive said ends of said 
pins, are counterbored to facilitate deflection of said pins. 
3. A device as set forth in claim 1, wherein said pins 
taper toward their ends to facilitate deflection. 
4. A device as set forth in claim 1, wherein said pins 
are positioned parallel to each other and in the same plane. 
5. A device as set forth in claim 1, wherein said pins 
are cylindrical. 
What is claimed is: 6. A device as set forth in claim 1, wherein said pins 
1. In a construction for interconnecting a hoist and a lo are constructed with their central portion having the same 
a first U-shaper support constructed to be connected t o  
a second elongated plate-like support constructed to be 15 
heavy object, the combination comprising: diameter as their ends. 
References Cited 
UNITED STATES PATENTS 
said hoist; 
connected to a large area of Paid heavy object: 
and a central portion, their ends carried within 
openings in the legs of said U-shaped support, said 
a plurality of elongated pins, said pins each having ends 3J161J162 12’1964 -------- 248-317 XR 
3,239,958 3/1966 Daum _ _ _ _ _ _ _ _ _ _ _ _ _ _  248-317 
3,295,801 1/1967 McDowall et a]. __--__ 248-18 
plate-like support having openings to receive the 20 
central portion of said pins and ,being positioned be- 
tween the legs of said U-shaped suppOt, said pins 
being supported by said supports like simple beams, 
.and, said pins being elastic to deflect within their 
elastic limit when the force on a pin exceeds a pre- 25 
determined amount, so as to distribute the load to ad- 
jacent pin. 
D* Examiner. 
v. FRANKLIN FOSS, Assistant ~ ~ ~ ~ i ~ ~ ~ .  
U.S. C1. X.R. 
214-10.5; 248-18; 294-81 


Device for handling heavy loads

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