US 3868139 A
A self-activating container handling spreader bar comprised of a rectangular-shaped frame with retractable loading centering arms extending from adjacent frame sides and with retractable load supporting dogs located conveniently on the frame. Contact switches activate the retractable arms when the spreader bar is placed on a container. Retraction of the arms draws the spreader bar into alignment with the top of the container and also energizes a circuit which locks the dogs and spreader bar on top of the container.
Claims available in
Description (OCR text may contain errors)
51 Feb. 25, 1975 United States Patent [191 Drelicharz Rumell..........................
[ CONTAINER HANDLING SPREADER BAR 3,688,933 9/1972  Inventor: Joseph A. Drelicharz, Oxnard, Calif. I
Primary Examzner-Evon C. Blunk  I Assignee: The United States of America as 7 Assistant Examiner ]ohnny Cherry represented y the Secretary of the Attorney, Agent, or FirmRlchard S. Sciascia; Joseph Navy: Washmgton, M. St. Amand; David OReilly  Filed: Feb. 28, 1974  ABSTRACT A self-activating container handling spreader bar comprised of a rectangular App]. No: 446,855
loading centering arms extending eeaw anus atO fi m as w m mm f r d e p a .h. S
sides and with retractable load supporting cated conveniently on the frame. Contact switches activate the retractable arms when the spreader bar is fi B6 7 O 2 BM 7M 2 D 7 m6 4 9F. 28 0 0 NR "1 n8 "A a e m m 04 MN F N 5 placed on a container. Retraction of the arms draws References Cited ee hh tt fs 0k Pm 0 m .m 6km S t t mn e o m LuW e .1 e wch F rt i g n n e o .I. a W S a 0 ne r. .WFw D aw o 3 OHM Q". .m m rm a 3d C b a de 8 a m. 0 r we Inn Dim me. 6 00 &cd BXR B 75m .ml4 MN 4 7. m m m m m m N m.m W mmm n Am m P m S m E .m Tmmm flk Tmmm SBTB D E440 T567 11999 NHHH U300 340 805 0 6 753 2 233 1 CONTAINER HANDLING SPREADER BAR BACKGROUND OF THE INVENTION Container handling and securing devices such as spreader bars have a long history in the art. The basic function of a spreader bar is to change the direction and distribution of forces needed to handle a load. The simplest example of such a device is a board forced between two ropes used to lift or support a load. In container handling devices, the simplest arrangement is comprised of a pipe bar lifted at the center or ends with four lines or straps manually hooked into bottom corner fittings to form a sling.
They can also be very complicated, such as an electro-hydraulic spreader available on the market which handles 20 to 40 foot containers. This device grips the container automatically, turns and tilts it, if necessary, and balances any eccentric load. Swinging of the load is checked by means of an electro-hydraulic suppressor system. Another complicated system known as the Clyde crane 30-ton extensible automatic spreader beam has telescoping motion, retractable corner guides and operation of latching mechanisms, all electrically operated. Typically these retractable corner guides move longitudinally along the spreaders axis and are designed to lift 20 to 40 foot containers. These are basically a flared angle iron extending below the spreaders used to remove small alignment errors and can only be used on free-standing containers. One frequent problem with these devices is thatof punching holes into container tops because, even though the latch mechanisms are electrically or hydraulically operated, they do not retract. Also, all spreader bars capable of handling a wide range of container sizes are, by their nature, complicated and heavy pieces of equipment. Another disadvantage is the relatively small margin of alignment error for such bulky equipment.
SUMMARY OF THE INVENTION The purpose of this invention is to provide a selfactivated spreader bar which eliminates the problems of punching holes in containers, precision alignment, and manual operation and is particularly adapted for use by helicopters. The spreader bar is comprised of a rectangular frame having arms extendable from adjacent sides and a skirt on the opposite sides. When positioned on a container, contact switches energize the arms retracting them until the arms drawthe spreader bar into alignment with the top of a container. When the arms become fully retracted, they energize a contact switch which in turn activates dogs, which lock onto receptacles in the container. The two contact switches underneath the spreader bar are connnected in series and are spaced apart such that the spreader bar must be substantially on the container in order for the retractable arms to be activated. These contact switches permit operation in blindness or under a hovering helicopter where precision placement is only accomplished by luck. The spreader bar allows a placement error on a container as much as half the width of the spreader.
OBJECTS OF THE INVENTION One object of the present invention is to provide a container handling spreader bar which eliminates the need for precision placement on a container.
Another object of the present invention is to provide a container handling spreader bar which eliminates the problems of punching holes in containers.
Still another object of the present invention is to provide a container spreader bar which is self-activated when positioned on a container.
Yet another object of the present invention is to provide a container spreader bar which automatically locks onto a container when the bar is in alignment with the top of the container.
Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of the self-activated container handling spreader bar.
FIG. 2 is a schematic diagram of the electrical circuit for operating the container handling spreader bar.,
FIG. 3 is a view of one of the self-locking dogs illustrating the manner in which they are kept retracted during placement of the container handling spreader bar.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 38 on swiveling U-bolts 40 attached adjacent to each corner of the rectangular frame 12. The cables 38 are all joined together by a swivel joint 42 or other suitable device for lifting. The length of the cables 38 are adjusted to balance the spreader bar in order to keep it substantially level. A DC. power supply located at some remote site (e.g., a helicopter) transmits power to the spreader bar via connector 44 and auxiliary cable 46.
The rectangular frame 12 is formed from box beams or channel irons which are welded or bolted together at their ends. Since these spreader bars are typically extremely large, sometimes 8 feet wide by 20 feet long, and even larger, the materials selected should be rugged with an effort made to minimize weight. Rods 48, welded or bolted diagonally across each corner of the rectangular frame 12 provide additional rigidity, if desired. Skirts l4 and 16 are fastened to one side and the adjacent end of the rectangular frame 12 to guide the spreader bar 10 into alignment with the top of a container. These fixed skirts 14 and 16 do not extend beyond the edges of the frame ,12 to allow for operation in ship cells, which have guide rails at each corner of the cell to align and secure the containers.
The retractable arms 18 and 20 are slidably mounted in a grooved support 50 which can be constructed from channel iron fastened to the rectangular frame 12. The retractable arms 18 and 20 are mounted so that there are no downward projections beneath the rectangular frame 12. That is, they are mounted so that they are entirely within the boundaries of the spreader bar 10 durproximately equally spaced along the side and (end, and
have hook-like'dow nward projections 52 enthe end of each arm, which are adapted 'to'catch the top edge of I a container to draw the spreader bar into alignment.
While one armtcould workfordrawingVthespreaderbar intoalignment with a container two parallehspaced apart armsare more suitable because they will auto;
ing retractionnThe retractable arms l8and20 are apretractable arms 18 and 2 are provided withqgelar racks 36 on'their upper surface, which can be an at tachment or formed integrally with the arms.-
yElectric motors 30 and 32 operate gears-34, which eh gage the ge'arraclts 36 on the retractable arms 18 and 20. The electric motors 30 and 32 are suitably supframe 12.
' ported so that'they do not'exte'nd below therectangular Self'locking dogs 22 are fastened at thetinside corrners of therectangular frame 12 so'that theywillbe aligned with receptacles in a container when; the
spreader bar, is drawninto the proper position; These self-locking dogs 22 are held in the retractedrpo V sition during the placement of the spreader bar, either electrically or mechanically, as shown in FIG. 3. HO. 7 V 3 shows a somewhat schematic diagram ofa typical dog J a 7 pass in the schem'aticvdiagram; rpoweris shown being ape r plied to'rcoils L1 through "Ll throughout thelocking of, a s the dogs,in order toassur'epositive engagementof the; r f a locking stud fiflr l'lowever powejrcould be cut off to the v V coils to'perlmit thedo'gs to free-fall into a loclging posi I tion} if desired; This 'couldwberaccornplished by provid I 'ing a centerOFF posi'tion' in switchSI. After free -fall m i of the locking 'stud60, power could bereapplied to assure fulllen'gagernent ofthe dogsoln the event that one i or both of switches S6 and s9-fait tooperate,then an additionalterminal con switch S1 would provide a by- 66, shown dotted in the schematic To remove the spreader bar from a contaiher, the p o-l lari ty'ofthe power-applied totermin'a'l'62 and 64 isretversedforithis purpose, normally openlswitchessSl a I "and S7 are provided whichfare closed'by action ofarms I8 and'20 shortlyafter retractionbegins. With switches S4 and1S7 :el sed andareversefpola'rity appliedat tera minal arid 64,c'urrent flowstthroughlines 68 and 70,
T reversing motors 30 and 32, causihgthe arms 18 and to be extendeduwiththe arms 18 and '20'fully re tracted,'switches Sfi and S9 remain closedand the reverse pola rity is alsoapplied throughline 72 to solenoid coils L5 through L8, associated'withthc dogs. causing an upward force on the lockingstud 60, thus releasing the dogs Thus extension of the mmsrsanaz'o and re a 1 assembly in which a pin 54 rides in a spiraling rail 56 l1:
- in the dog housing 58.-Thepin 54 is rigidlyattaehed to V the locking stud 60, causing itto rotate: into a locking position as it drops or is forced do whward into a receptacle. ,When the lockingstud fill is mate retractedpos'ie tion, the pin 54 is retained at the top of thexrai'l S6tby,
a lunch; latch or some other suitable means, suchtas a slight downward curvature of the rail 56.
The electricalcircuit foroperating the container handling spreaderbar lfl is shown schematically in; F1632.
' Power is supplied to the spreader'bar 10 through a conector 44, schematically illustrated in FIG 2as terminals 62 and 64. SwitchSl, which'may beremotely located in a helicopter or otherrdevice for operating the t spreaderbar, applies the input power to the circuit.
When switch S1 contacts terminalsb the spreader bar is ready for automatic operation.
vNormally open contact switches S2 'anduS3 are co nnected in series so that both must be closed in orderfor retraction of arms 18 and 20 to begin, They are physically separated on a centerline of the spreaderbar to 7 S2 and S3 are both closed, power is applied to motors 3G and 3 2 through normal] t assure an approximately a;ligned condition before the 7 electrical circuit is; energized. When contactswitches y closed switches'SS andSS' t and diodes CR2 andCRli The motors 30 and'32 begin retractionof arms land 20 into the rectangular't'rame 7 l2. Arms 18 andi20, when fullyretracted; act to open a and S8 shuts off the motors 30 and 32,ustopping the re-l. j
traction of the arms 18 anditlgwhen the, switches S6 7 and S9 are closed. power is applied to solenoid coils L l through L4, associated withfleach of theselfslockirtg dogs 22 (HO. 1 through, diodeCRty. r'lhe'power' applicd to solenoid coils [I through L4 appliesa downward force (indicatcd by: the arrows), releasirrg thez' dogs and allowing the pin 54' to slidedown the rail56, causing the locking stud todrop into a receptacle in a container'and lock into position. i; Y
tached s I g i g I Referring again to ElG. l,contactswitches S2 and S3 wouldgb'ei located on the lengthwise'centerline'of the spreader bar 10] beneath the retractablelarms l8 ap proximately at 76. These switc hes would extend slightly 7 traction of the dogs, from the contaiher' begins sirnultai neously; The upward} force on' the locking stud 60' 1 causes pin ,54to ride, upward in' rail 56 until latches f a atthe topof the railJ 3 I e a 7. Again, if eitherory'both ofswitchessfi and S9are int operable," reverse current maybe applied to the dogs through terminal c of switch Slland line 66, 'to retract I the dogs from the containerySinc'e switches S4a nd'S7 are'closecl byxarms l8 and 20 shortlyafter retraction begins, diode CR1 assures proper polarit y duri'ng' re-f traction. Conversely, since switches SSyand S8 close shortly after extension of theparrns 18 an1d20 is begun, diodes CR3 and CR5 assure proper polarity duringiex tension of the arms. Diodes'CR6 arid CR7 perform the I same function for the retractable dogst y: r V d be eliminated and asingle set of'solenoid'coilslLl throughL'4 used'to If desired; diodes CR6 and CR7 coul release or retract the locking Stud 60; in thiscase, coil L1 would be, connected. directly toswitch S9, permit-w ting forward currenti to release'the locking studs and reverse :currenttto retract themrQHowever, theacldir' fitional solenoid coils L5 through LPtovide more flexi bility in thatlit is abacleup systemqtofassure thatthe I lockingstuds can be electricallyretracted; In the event one of the coils 'Llfthrough, L4 fail; the' dogs could be a locked manually; Anotherlvari ationwould be to con I nect the solenoid coils L1 through L4 in 'parallelto per mitele'ctrically locking the other dog; even if one of the coilsfailedpThe dog which did not .operate would; l therrbe releasedmanually. Howeven this is not desirable because if oneof the dogsdoes notlockglthen con-k siderabledamage could be caused in attempting to lift the container with one corner of the spreaderbar' unatf below the lower plane of the rectangularframe 12 in order that they be energized whenthe spreader bar 10;
for applying power directly to the dogs over line is placed on a container. Switches S2 and S3 can be mounted in any suitable manner at the position shown and a hinged plate (not shown) could be provided to assure that they are energized when the spreader bar is placed on a container. S4 would be mounted underneath either of the retractable arms 18, approximately at 74 so that it would be energized shortly after retraction of the arm begins. In the same way, contact switch S7, associated with retractable arms 20, would be mounted approximately at 78. Contact switches S5 and 56 would be mounted adjacent each other in association with one of the retractable arms 18, approximately at 80. They would be simultaneously operated by arms 18 at full retraction. Contact switches S8 and S9 would be mounted in the same manner in association with one of the retractable arms 20, approximately at 82. Alternatively, contact switchesSS and S6 could be mounted in the side rail of rectangular frame 12 for operation by the end of the retractable arm when it is fully retracted. If desired, contact switches S5 and S8 could be mounted slightly ahead of contact switches S6 and S9,
in which case the latter switches would be energized by I ward after alignment is complete until they are flush with the outer surface of the rectangular frame 12.
Thus, there has been disclosed a self-activated container spreader bar which eliminates the problem of punching holes in the tops of containers and eliminates substantially the need for precision placement and manual operation, whether by helicopter or otherwise. The character of this spreader bar system allows placement in practically blind areas with an error of as much as an estimated half the width of the spreader.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. it is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.
1. A container handling spreader bar comprised of:
a. a rectangular frame;
b. a skirt attached to the frame and extending downward along one side and the adjacent end;
c. first and second pairs of substantially parallel, spaced apart, movable arms mounted in the frame and extendable from the side and end opposite the skirt:
d. downward projections on the ends of said armsfor drawing the spreader bar into alignment with the top of a container after placement; 7
e. means for extending and retracting the movable arms;
'. means for automatically energizing the arm retracting means when the spreader bar is placed on top of a container;
g. four self-locking retractable dogs attached to each inside corner, of the frame;
h. means for retracting the dogs;
i. means for keeping the dogs retracted during positioning of the spreader bar; and
j. means for automatically releasing the dogs when the spreader bar is aligned with the top of a container.
2. The container handling spreader bar of claim 1 wherein the means for extending and retracting the arms comprise:
a. an electric motor for each pair of movable arms attached to the top of the rectangular frame and having gears engaging a rack on each movable arm; and
b. means for reversing the polarity of the motor to permit extension or retraction of the arms. I
3. The container handling spreader barof claim 2 wherein the means for energizing the arm retracting means comprises at least two contact switches mounted underneath the rectangular frame, equally spaced from each end along the lengthwise centerline.
4. The container handling spreader bar of claim 3 wherein the means for reversing the polarity of the motors to permit extension or retraction of the arms comprises:
a. a first pair of series-connected switches, one of said first switches associated with each pair of arms and adapted to be closed when the arms are extended, and open when the arms are fully retracted; and
b. a second pair of series-connected switches, one of said second switches associated with each pair of arms and adapted to be closed when the arms'are retracted, and open when the arms are fully extended.
5. The container handling spreader bar of claim 4 wherein the means for keeping the dogs retracted comprises a spiraling rail in the dog vhousing, and a pin attached to the dog slidably engaging in the spiraling rail.
6. The container handling spreader bar of claim 5 wherein the means for releasing the dogs comprises:
a. a solenoid coil associated with each dog;
b. a pair of limit switches associated with each pair of retractable arms; said limit switches being closed I when the arms are fully retracted; whereby the solenoid coil associated with each dog is activated, releasing the pin to slide down the spiraling rail to lock the dogs onto the container.
7. The container handling spreader bar of claim 6 wherein said means for retracting the dogs comprises:
a. a second solenoid coil associated with each dog;
b. means for applying a reverse current to the second solenoid coils, thereby exerting an upward force on the dogs, causing theretaining pin to slide up the spiraling rail and latch the dogs in a retracted position.
8. The container handling spreader bar of claim 1 wherein the downward projections on the ends of the movable arms are formed with angled cam surfaces to force the ends of the arms upward after alignment is complete so that the arms are flush with the outside surface of the rectangular frame.