US2996310A

US2996310A - Missile transfer dolly

Info

Publication number: US2996310A
Application number: US800901A
Authority: US
Inventors: Eugene S Culver
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-03-20
Filing date: 1959-03-20
Publication date: 1961-08-15
Anticipated expiration: 1978-08-15

Description

Allg 15, 1961 E. s. cULvx-:R

MIssILE TRANSFER DOLLY '7 Sheets-Sheet l Filed March 20, 1959 INVENTOR ATTORNEYS Aug. 15, 1961 E. s. CULVER 2,996,310

MISSILE TRANSFER DOLLY Filed MaICh 20, 1959 7 Sheets-Shea?l 2 mvENToR Eugene S. Culver BY y o @my ATTORNEYS Aug. 15, 1961 E. s. cULvER y 2,996,310

MIssILE: TRANSFER DoLLY '7 Sheets-Sheet 3 Filed March 20, 1959 aJvvuJ-z ATTORNEYS Eugene S. Culver '7 Sheets-Sheet 4 Filed March 20, 1959 INVENTOR Eugene 5. Culver ATTORNEYS Aug- 15, 1961 E. s. CULVER MISSILE TRANSFER DOLLY 7 Sheets-Sheet 5 Filed March 20, 1959 2 a @Em INVENTOR Eugene 5. Culver BY i@ W MM ATTORNEYS 7 Sheets-Sheet 6 INV EN TOR Eugene 5. Culver CQ f@ ATTORNEY 8 Aug. 15, 1961 E. s. CULVER MIssILE TRANSFER DoLLY Filed March 2o, 1959 Aug 15, 1961 E. s. cULvER 2,996,310

MssILE TRANSFER DoLLY Filed March 2o, 1959 7 sheets-sheet fr INV ENTOR Eugene S. Culver Q f am 1, BY W ATTORNEYS United Sates 2,996,310 MISSILE TRANSFER DOLLY 'Eugene S. Culver, Arlington, Va., assigner to the United States of America as represented by the Secretary of the Na Vy Filed Mar. 20, 1959, Ser. No. 800,901

8 Claims. (Cl. 2S0-124) This invention relates generally to material handling apparatus which is especially suited for transporting ordnance devices, such as guided missile components, from ship to ship at sea, or from dockside to ship. More specifically, the invention pertains to an improved transfer dolly which constitutes a significant part of an eicient, integrated system for handling the components of a guided missile from the time of issue thereof from a shore-based depot to delivery aboard a missile firing ship, including introduction of such missile components into the ships strike-down system.

Another object of the invention resides in the provision of a transfer dolly which will function to protect missile components during the stages of handling where shock loading may 4become excessive, and which will at the same time permit extreme mobility of such components on shipboard, said dolly employing means for isolating such components from shock from any direction in the horizontal plane, and means for providing shock protection in the vertical plane, the last-mentioned means being constituted by a unique constant deceleration torsion bar suspension system.

Still another object of the invention is to provide a missile component transfer vehicle which incorporates a novel dead man brake mechanism that will insure immediate arrestrnent of the vehicle after it has been deposited on the deck of a ship, but which may be quickly released, either by hand or by the action of a hoisting sling, for permitting movement of the vehicle to a desired location on the deck.

A further object of the invention is to provide a missile component transfer dolly that is constructed of light weight, high strength steel, heat treated to attain very high working stresses, for insuring maximum protection for missile components thereon.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. l is a perspective view of the improved transfer dolly with a component cradle mounted thereon;

FIG. 2 is an end view of the transfer dolly;

FIG. 3 is a side elevation of the dolly;

FIG. 4 is an enlarged detail side elevation showing the positions of the supporting legs, the torsion bar levers, and the shock absorber mechanism under impact conditions;

FIG. 5 is a detail view of one of the torsion bars employed, together with its associated levers;

FIG. 6 is a top plan view of one end of the transfer dolly;

FIG. 7 is an enlarged detail perspective view showing particularly the brake cylinder mechanism, portions of the torsion bar and shock absorber mechanisms, and one of the cradle latches;

FIG. 8 is a detail perspective view showing the torsion bars and the mountings therefor;

FIG. 9 is a diagrammatic representation of the basic suspension system;

FIG. 10 is a detail perspective view showing a modified cradle latch arrangement;

"ice

FIG. 11 is an enlarged front elevation of one of the caster wheel structures; and

FIG. 12 is a side elevation, partly in section, of the caster wheel structure shown in FIG. 11, particularly illustrating the brake mechanism.

Briefly, the transfer dolly constituting the present invention is a dolly of high strength tubular frame construction including a nearly uniform (within 1 percent) deceleration suspension system to provide the maximum in energy absorption in a minimum area of deection. The purpose of such a design is to provide the maximum protection vfor a load from shock, while also permitting easy movement of the dolly after deposit thereof on the deck of a ship, and extreme ease and speed in removing the load from the dolly. The weight of the dolly has been reduced to the minimum to assure ease in handling by manpower on a rolling deck and during ship-to-ship or ship-to-shore transfer operations.

The suspension system that provides protection from the most likely overload, Le., an uncontrolled free-fall drop to the deck of a ship, comprises basically three lever linkage arrangements at each end of the dolly that act on pairs of torsion bars controlled by hydraulic shock absorbers. The legs, with full castering wheels thereon, are individually sprung, for maximum flexibility. The castering Wheels are provided with locks to prevent accidental directional changes. The operation of the linkage system is such that the Hookes law action of the torsion bars is multiplied to produce nearly uniform deceleration if the dolly is accidentally dropped. The operation of the linkage system is also such that it will absorb twice as much energy as previously known suspension systems while transmitting the same or less shock to the suspended load.

The cradle employed with the transfer dolly, for carrying a missile component or other load, is formed of light gauge sheet metal properly reinforced. The cradle is padded with sponge rubber to prevent chang a missile component or other load therein. Quick operating latches are employed to permit rapid removal of the cradle from the dolly. The cradle is so designed that a number of them may be stacked, by the use of suitable cranes or trucks, if desired.

Referring to -the drawings in more detail, the general arrangement of the improved transfer dolly is shown in FIGS. 1, 3, and 6. The dolly comprises a frame 10 which includes side rails 11 and 12 and generally semielliptical end rails 13 and 14, the end rails being connected to the side rails by suitable couplings, one of which is indicated at 15. The frame is substantially rectangular in shape and is formed of light Weight, high strength steel tubing, heat treated to attain extremely high working stresses, say of the order of approximately 120,000 p.s.. Mounted on the side rails near their opposite ends are vertically extending generally inverted U-shape guard rails 16. Extending transversely of the frame near the opposite ends of -the side rails are tubular supports 17, best seen in FIGS. 6 and 7, and carried on said supports are support plates 17a. The supports 17 carry cradle mounts 18 which are mounted on preferably rubber shear blocks 19, said mounts having flat upper surfaces and carrying latches 20 at their opposite ends. 'Ihe cradle mounts 18 and latches 20 will be described in more detail hereinafter. The cradle mounts and latches cooperate with mounting saddles 21 on a cradle 22 (FIG. l) which is designed to carry a missile component or other load on the dolly.

The torsion bars which constitute a part of the deceleration system for the transfer dolly fare mounted in pairs and extend transversely of the frame near its opposite ends. Since the pairs of torsion bars are identical 3 in constructionV and application, a description of one pair will suflice for both. As best seen in FIGS. 5, 6, 7 and 8, the torsion bars of one pair are indicated at 23 and 24 and are of cylindrical cross-section. Referring particularly to FIG. 6, the torsion bar 23 has one end mounted for limited rotation in

plates

25 and 26 which are securedl to and extend above the side rail 11, and the other end rigidly mounted on a 'plate 27 which is secured to .and extends above the side rail 12. Secured to the bar 23 near the rail 11 and extending above the frame is a .bar lever 28. The torsion bear 24, which lies in parallel spaced relation to the bar 23, has one end rigidly secured to the plate 25 and the other end mounted for limited rotation in the plate 27 and in a companion plate 27a. A 'bar lever 29, identical to the bar lever 28, is rigidly secured to and extends above the torsion bar 24 near the Vside rail of the frame 10. Asbest seen in FIGS. and 7, end plates 30 and coupling plates 3i provide suitable means for rigidly connecting the torsion bars to the frame and the levers to the torsion bars.

Four leg assemblies are used for supporting the transfer dolly. Ihey are independently mounted on the frame and constitute a part of the deceleration system, cooperating with the tor-sion bars and their associated bar levers. One of the leg assemblies is mounted on the frame 1G near each corner thereof. The leg assemblies are identical so that a description of one will sutiice for all four.

The best showing of one of the -leg assemblies will be found in FIG. 4 of the drawings, a typical leg assembly being indicated generally `at 32. It comprises a leg element 33, a lever element 34, and a brace 35. The leg element and brace are of tubular hardened steel, said leg element extending below the frame and terminating at its lower end in a caster mount 36. At its upper end the leg element is mounted on the frame by a trunnion 37 (FIG. l). The lever element 34 is constituted by ya pair of parallel spaced plates 3S and 39 which are of triangular shape. As mounted the plates resemble, in side elevation, a generally equilateral triangle with the base lying in a plane nearly normal to the plane of the side rail l2 and the apex extending toward the nearest end of the-frame, when the deceleration system is unstressed. The lowermostcorner of the lever element straddles the upper end of the leg element 33. on the trunnion 37, and the upper end portion of the brace 35 is secured to said lever element near the apex thereof, thus adding rigidity to the lever element. The lower end portion of the brace is secured to the'leg element 33 near the caster mount 36.

Positioned between the apex of the lever element 34 and Vthe frame is in single lacting shockabsorber 40 which includes a cylinder 41 that has one end connected to a trunnion 42 journaled by the legs of a yoke 43 secured to the side rail 12 adjacent the vertical portion of the guard rail 16 nearest the end rail 13. The shock absorber carries a piston including a piston rod 44 which is pivotally connected to the apex of said lever element 34, a conventional sump 45 being mounted on the upper surface of the cylinder 41. A cable 46 connects the upper end of the lever 28 with the upper end of the lever element 34.

As will be explained in more detail hereinafter, the pairs of

torsion bars

23 and 24 are partially Vpreloaded during installation, With the result that the lever elements of the leg assemblies are normally rocked in the direction of the ends o fthe frame by the action of the levers 28 and the cables 46. To prevent movement of the leg assemblies beyond the unloade positions shown in FIG. 3 by the `action of said prestressed torsion bars, cables 47 are employed and are connected from points near the upper ends of the lever elements 34 tothe side rail 12 near the innermost vertical members of the guard rails 16.

The caster and brake. structure lare shown in FIGS. 11 `and l2 and will now be described. Each of the four casters employed` includes, in addition to a caster mount 36, a yoke 48 having a hollow stem 49. The stem 49 is mounted for full 360 degree rotation in the mount 36 by bearings 50 and 51, and is limited against vertical displacement by a nut 52 which engages a top plate 53. To prevent fouling by salt water in the event of accidental immersion of the dolly, suitable O rings seal the mount 36 at its upper and lower ends. The yoke 48 rotatably mounts a caster wheel 54 which has sets of brake studs 56, the studs of each of said sets being arranged in an annular series and projecting from the side faces of the wheel. The brake studs 56 are selectively engageable by notched shoes 57 that are mounted between the legs of the yoke and at opposite sides of the wheel by a cross rod 5S, and are connected t0 a plunger 59 in the hollew stem 49 by links 60 and 61. A spring 62 in the stem normally urges the plunger downwardly for engaging the shoes with studs 56 at each side of the caster wheel 54.

A hydraulic brake cylinder 63 is pivotally mounted on the brace 35 of the leg assembly by a U-shape strap 64, with the piston 65 of said cylinder rigidly secured to said brace by a bracket 66. The strap 64 is connected to the upper end of the plunger 59 by a link 67 and a nut 68. It will be seen that hydraulic lluid introduced to the cylinder 63 will move said cylinder away from the fixed piston 65 for raising the link 67 and the plunger 59, when the brake shoes will be disengaged from the studs 56. To prevent directional changes in wheel attitude of the caster wheel 54, a spring Pressed lock plunger 69 is normally engaged in a suitable opening or notch in the forward end of the yoke 48. A handle 70 on the plunger 69 may be raised for freeing said plunger from the hole or notch, when the caster may be rotated as desired. The casters may be locked at degree angles to each other for providing a parking brake for the dolly.

The brake mechanism described above forms a part of a hydraulic brake system for the transfer dolly. More specifically, in addition to the casters and their associated brake structures, mounted on the four leg assemblies, there is provided a master cylinder having main and auxiliary brake pistons. A hydraulic line H, as best shown in FIGS. 1 and 7, connects the master cylinder with frame 10, as at 10', the frame being in iluid communication with the cylinder 63 of each caster in any conventional manner. The hydraulic brake system is best seen in FIGS. 4 and 7 of the drawings. The master cylinder is shown `at 71 and the main and auxiliary pistons at 72 and 73, respectively. The master cylinder 71 is mounted on an extension of the plate 25 near one corner of the frame with the pistons projecting toward the nearest upright section of the yadjacent guard rail 16. The main piston 72 is operated manually by a lever 74, mounted on `and extending along the horizontal section of the guard rail 16, and a connecting rod 75. The auxiliary piston is operated by a cable sling 76 having a branch 77 connected to said auxiliary piston by a pivoted link 78.

Briefly, the hydraulic brake system operates as follows. When the transfer dolly is being moved from, say an ammunition ship to a cruiser, rand is being handled according to the well-known Burton (high-line) method, the caster brakes are maintained in the ot^positions, that is, with the notched shoes 57 out of engagement with the studs 56 of the caster wheels, due to operation of vthe auxiliary piston 73 by the branch 77 of the sling 76. When the dolly contacts the deck of the cruiser, the sling will slacken and pressure on the piston Will be relieved. The shoes 57 Will then engage the studs 56 for locking the caster wheels and preventing free rolling of the dolly onthe deck. Release of the brakes, for permitting desired movement of the dolly, may be accomplished by depressing the lever 74 for operating the main piston 72. The caster brakes will be reapplied immediately upon release of the lever 74. The operation of the auxiliary piston by the sling 76, however, involves a two second lag, to permit the leg assemblies to deflect normally upon impact with the deck, if the dolly is dropped, without skidding the caster wheels.

The mechanism for mounting and retaining the cradle 22 on the transfer dolly will now be described. As shown diagrammatically in FIG. 2, the dolly is so designed that it may accommodate a relatively narrow cradle or one of `greater width.

The cradle mounts 18 extend along the tubular supports 17 thereabove, on the shear blocks 19 and the plates 17a. The mounts 18 are of identical construction so that a description of one will suce'for both of them. Each mount 18 is substantially inverted U-shape in cross-section and has a resilient pad l80 on its upper surface. At the opopsite ends of the mount 18 are pairs of aligned notched slots 81, and mounted in each said pair of slots for swinging movement are links 82 which are pivotally connected at their upper ends, by bolts 82a, to one of the latches 20, said latches being of generally oblong, rectangular shape. The latches 20, as best seen in FIG. 7, are each formed with a recess 83, the walls of which are apertured near their free ends to receive the end portions 84 of a hairpin shape spring latch element 85.

By referring to FIGS. 1 and 2 it will be seen that the latches 20 at each end of the mount 18 may be swung to engage between spaced walls of the mounting saddle 21 of the cradle 22, the tines of the spring latch elements being manually compressed to permit entry of the end portions 84 between said walls. Upon release of pressure upon the tines, the end portions 84 will engage in suitable openings 86 in said mounting saddle walls, and the bolts 82a will engage in notches 85a in said walls. By moving the links 82 in the notched slots 81 the latches 20 may be positioned for retaining on the dolly either a relatively wide cradle, such as is designated A in FIG. 2, or a relatively narrow one, shown at B.

To retain the mounts 18 against displacement from the dolly, chain link couplings 87 (FIG. 2) provide nonrigid connections between the centralportions of said mounts and the transverse supports 17.

Referring now to FIG. l0, wherein a modified latch structure is shown, 'a portion of a cradle similar to the cradle 22 is shown at 88. The cradle 88 is provided with a mounting saddle 89 having spaced walls 90 formed with aligned notches 91 and openings 92, the latter similar to the openings 86. The cradle 88 is positioned on a cradle mount 93 which is supported on shear blocks, one of which is shown at 94; a transverse support 95 similar to the support 17; and a support plate 96 similar to the support plate 17a. The cradle mount 93 is generally similar to the cradle mount 18 except that, in lieu of the slots 81 a loop is provided at each end, one of said loops being shown at 97. Latches 98 are mounted for swinging movement in the loops 97 on each end of the mount 93 by spaced links 99, a pin 100, and bolts 101. The latches 98 are similar to the latches 20 and each includes a latch element 102 having end portions 103.

iIn use, when it is desired to secure a cradle on the dolly, employing the modified latch structure, the latches 98 are swung upwardly to engage between the walls of the mounting saddle 89, the latch elements 102 being compressed manually for permitting entry of the end portions 103. When manual pressure is relaxed, the end portions 103 will be engaged in the openings 92 and the bolts 101 seated in the notches 91, in latching position.

As stated hereinabove, the shear mounts 19 provide protection by isolating the dolly load from shock in all directions in the horizontal plane. Shock protection for such load in the vertical plane is provided by the substantially constant deceleration torsion bar suspension system, the operation of which will now be described in more detail.

The basic torsion bar suspension system is shown in FIG. 9, and the action is as indicated in the following formula:

The load at P in the vertical direction results in an increasing torque at Pivot T1, this increase in torque taking place at a rate equal to the linear Hookes law rate of the torsion bar, which is acting at T1, by the following:

This system produces pure uniform deceleration only if link L is infinitely long, where the interaction of R1 and R2 would be zone. In the actual system described and illustrated the link L is less than 36 inches long, which introduces a slight modification of the sine function, resulting in a slight (less than 1%) non-linearity in the system. Therefore, it has been stated that the system produces substantially uniform deceleration.

At installation, `as previously stated, the torsion bars 23 and 24 are preloaded approximately 35 degrees and `are restrained in such positions by the cables 47. This initial wind-up establishes the load at which the leg assemblies begin to deflect. Por a tested prototype the load was set at four gravity units, i.e., four times the weight of the load on the dolly. Thus, in order to activate the suspension system, the energy resulting from dropping the loaded dolly must be sufcient to exceed the energy prestored in the torsion bars. That is, since the torque applied to the torsion bar is proportional to the angular deection thereof, it is apparent that the load must increase in order to attain greater deflections. To combat this undesirable condition the load is transmitted from a wheel of the dolly to a torsion bar through a series of multiplying cosine linkages such that when the initial preload of four gravity units has been reached, the leg assemblies begin to deflect and the loading remains constant for the full deiiection of the system. If a simple Hookes law spring suspension system were used and other conditions were equal, the shock transmitted to the dolly load would be twice that produced by the 'system above described. The shock absorbers 40 effectively control the rebound stroke of the suspension system, in a conventional manner,

The cradles 22 are so designed that they may be easily handled by a suitable hoist or by a fork lift truck, and may be stacked while in storage, if desired.

Obviously many modifications and variations of the present invention are possible in the 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.

What is claimed is:

l. In a transfer dolly, a frame, a leg assembly pivotally mounted on the frame and having Ia lever element and a leg element, said leg assembly being deflectableupon impact of the dolly with a surface, a spring on the frame and having one end secured to said frame and the other end mounted for limited movement, a bar lever on the spring, first ycable means connecting the bar lever to` the lever element, said spring being so preloaded that the energy required to deflect the leg assembly upon imp-act of the dolly with a surface must exceed the energy prestored in said spring, and second cable means on the frame and on the lever element for retaining the spring in preloaded condition, said leg assembly, rst cable means, lever elements and said bar lever constituting a multiplying linkage and cooperating with said spring to provide a substantially constant deceleration suspension system for the frame.

2. A transfer dolly as recited in claim l, wherein the lever element of said leg assembly is iconstituted by spaced parallel triangular plates carried by said -leg element with the leg element disposed therebetween, said leg assembly including additionally a brace extending between and 7 secured to the plates at a point near the apices ofY said plates.

3. A transfer dolly yas recited in claim 1, including additionally a caster mount carried by the leg assembly at the lower end of the leg element, a yoke rotatable vin the mount, a caster carried by the yoke, and'means on the caster mount engageablerin said yoke for locking said yoke against rotation in the mount.

4. A transfer dolly including a rectangular frame, guard rails on the frame, leg asemblies supporting said frame near each corner thereof, springs on the frame and connected to the leg assemblies, said leg assemblies being deflectable against the tension of said springs upon impact of the dolly with a surface therebeneatb, a sling for lifting said dolly, casters on the leg assemblies, brake mechanisms on the casters, brake actuating means on the frame and connected with said mechanisms, and means onthe sling and connected to said brake actuating means and operable upon release of the sling for actuating the brake mechanisms for preventing movement of the dolly on such surface following said sling release.

' 5. A 'transfer dolly as recited in claim 4, wherein said brake mechanisms include brake cylinders and said brake actuating means comprises a master cylinder connected with said brake cylinders.

6. A transfer dolly as recited in claim 4, wherein said brake mechanisms include brake cylinders and said brake actuating means comprises a master cylinder, a hydraulic line in fluid communication with the master cylinder and brake cylinders, said master cylinder having main and auxiliary pistons, meansA connecting the sling to the auxiliary piston, and manually engageable means on the frame and connected to the main piston, said manually engageable means being operable for shifting the -auxiliary piston for releasing the brake mechanisms after actuation thereof by release of the sling.

7. A transfer dolly, as recited in claim 6, wherein said manually engageable means includes Va lever pivoted on one of the guard rails, and a connecting rod extending between one end of said leverand the main piston.

8. In a transfer dolly, a frame, a plurality of Wheel assemblies pivotally mounted on the frame for supporting said frame above a surface, said assemblies being deflectable upon impact of the dollyY with-such surface, each of said assemblies including a lever element, `a leg element connected to said lever element at an angle thereto, said lever element comprising spaced parallel triangular plates having lower end portions straddling the leg element at the point of pivotal connection of the assembly with the frame, and a brace extending between the leg element and points near the apices of the lever element, a torsion bar spring having one end secured to the frame and the other end axially movable with respect to said frame, a bar lever on said other end of said torsion bar, and a lcable connecting the bar -lever with the lever element, said torsion bar spring normally retaining the wheel assemblies in undeected position.

References Cited in the tile of this patent UNITED STATES PATENTS 661,982 Harris Nov. 20, 1900 1,390,852 Woolley Sept. 13,1921 1,816,393 Morris July 28, 1931 2,033,493 Straussler Mar. l0, 1936 2,305,807 Gramatzki Dec. 22, 1942 2,395,768 Svoboda Feb. 26, 1946 2,512,941 Johnson June 27, 1950 2,606,039 La Rue Aug. 5, 1952 2,730,375 Reimspiess Ian. 10, 1956 2,792,231 Compton May 14, .1957 2,911,231 Allison Nov. 3, 1959 FOREIGN PATENTS 995.581 France Aug. 22, 1951