US3448874A

US3448874A - Mobile crane with spaced pivotally mounted booms

Info

Publication number: US3448874A
Application number: US650757A
Authority: US
Inventors: Edwin O Martinson
Original assignee: Koehring Co
Current assignee: Koehring Co
Priority date: 1967-07-03
Filing date: 1967-07-03
Publication date: 1969-06-10
Anticipated expiration: 1986-06-10

Description

June 10, l1969 MOBILE CRANE WITH SPACED PIVOTALLY MOUNTED BOOMS Filed July s, i967 E. O; MARTINSON Sheet of 5 -BY l/ Jun@ 10, 1969 E. o. MARTlNsoN r3,448,874

MOBILE CRANE WITH SPACED PIVOTALLYMOUNTED BOOMS Sheet Filed July 5, 1967 INVENTOR. [wmv /wmvf/v 'June 10, 19692 -11.0. MARTINSON;

MOBILE CRANE wma s PAcEn PIVO'TALLY rMOUNTED Booms Filed July s, 1967 I snee-tv3 or- 5 INVENTOR.

E. o. MARTlNsoN June 1d, 1969` MOBILE CRANE WITH SPACED PIVOTALLY -MQUNTEDB-OOMS Fild July s. 1967 sheet y4f iofv 5 June 10, 1969 E. O. MARTINSON MOBILE CRANE WITH SPACED PIVOTALLY MOUNTED BOOMS Filed July s.' 1957 Sheet 'Ill rm P ,ALI

l y INVENTOR.

bw/xv infr/#5441' BY' l U.S. Cl. 214-75 United States Patent O 3,448,874 MOBILE CRANE WITH SPACED PIVOTALLY MOUNTED BOOMS Edwin O. Martiuson, Milwaukee, Wis., assignor to Koehring Company, Milwaukee, Wis., a corporation of Wisconsin Filed July 3, 1967, Ser. No. 650,757 Int. Cl. B60p 1/46, 1/48; B65g 67/02 6 Claims ABSTRACT OF THE DISCLOSURE A crane for transferring semi-trailers or their cargo containers from the road to railroad at cars and vice versa, comprises a wheeled vehicle frame, front and rear booms swingable independently of each other to pickup positions at either side of the vehicle frame, a truss flexibly suspended from the booms by front and rear hoist rams; and front and rear pairs of grapple arms swingably suspended from front and rear crane trolleys on the truss.

BACKGROUND OF THB INVENTION Field of the invention The invention relates to material handling apparatus, and it is concerned more particularly with a mobile crane tor use at railroad yards where truck drawn semi-trailers or the cargo containers of such trailers are loaded upon and unloaded from railroad at cars. Description of the prior art.

Description of the prior art The loading of semi-trailers, or of the cargo containers of such trailers, upon at cars for rail shipment has become an accepted practice in the trucking industry, and special cranes known as TOF (trailer on at car) cranes are commonly employed for that purpose.

One type of TOF crane which has heretofore been suggested comprises a relatively wide and high traveling gantry Which straddles the railroad track and a truck road next to it. Movably suspended from the gantry is a grapple apparatus picks it up at the road side of the gantry, tween the rail side and the road side of the gantry. In order to load a trailer or container on a flat car the grapple apparatus picks it up at the road side of the gantry, moves it over to the rail side and deposits it on the flat car. Likewise, in order to unload a trailer or container from a ilat car, the grapple apparatus picks it up at the rail side of the gantry, moves it over to the road side and deposits the trailer on the road or the container on a trailer chassis, as the case may be.

In this type of crane the grapple apparatus engages the trailer or container from opposite sides at spaced points intermediate its front and rear ends; and front and rear hoists on the gantry raise and lower the .grapple apparatus together with the grappled trailer or container. The required large size of the gantry, and the shift and hoist mechanisms for the grapple apparatus render the gantry type of TOF crane relatively bulky and expensive.

Another type of TOF crane which has heretofore been suggested comprises a side loading vehicle which may be pulled up alongside a railroad flat car and operated to swing a trailer or container from the road side to the rail side of the vehicle for loading, and from the rail side to the road side for unloading. This type of TOF crane is less bulky and expensive than the gantry type but, as heretofore constructed, it lacks the stability and load handling capacity of the gantry type crane.

ice

SUMMARY 0F THE INVENTION The present invention relates to a TOF crane of the side loading vehicle type, and its principal object is to overcome the heretofore existing shortcomings and disadvantages of that type of crane without sacricing its advantages, that is, greater compactness, better maneuverability and lower manufacturing costs as compared with the gantry type of TOF crane.

More specifically, it is an object of the invention to provide an improved TOF crane of the side loading Vehicle type which incorporates an articulated, laterally swingable superstructure including a forward pair and a rearward pair of grapple arms which are engageable with trailer body or container at longitudinally spaced portions between its front and rear ends.

A further object of the invention is to provide an improved TOF crane of the mentioned character which will be oper-able efficiently regardless of whether its chassis is positioned exactly parallel or somewhat non-parallel to the flat car which is to be loaded or unloaded, and regardless of whether the crane chassis extends exactly parallel or somewhat non-parallel to the trailer or container which is to be transferred.

A further object of the invention is to provide an improved TOF crane of the above mentioned character which incorporates a forward and a rearward pair of grapple arms, and a mechanism for clamping the grapple arms of each pair against a trailer body or cargo container from opposite side by translatory movement of the arms towards each other, and also for swinging the arms at right angles to their direction of translatory movement.

A still further object of the invention is to provide yal1 improved TOF crane of the mentioned character which will be operable to transport a trailer or container be, tween loading and unloading locations, and which incorporates a simple and conveniently operable mechanism for securing a picked -up trailer against shifting on the crane chassis during travel of the crane from one location to another.

A still further object of the invention is to provide an improved TOF crane of the mentioned character which may be collapsed into a self-contained compact unit for shipment, and which may readily be changed over from its collapsed transport condition into an erected working condition with a minimum amount of elort and within a relatively short time.

These and other objects and advantages are attained by the present invention, various novel features of which will be apparent from the disclosure herein of :a preferred embodiment of the invention, and Iwill be pointed out `by the appended claims.

Referring to the accompanying drawings:

FIG. 1 is a side elevation of a TOF crane embodying the invention;

FIG. 2 is a rear view showing an adjusted condition of the crane of FIG. 1 in full lines, and two other adjusted conditions in dotted lines;

FIG. 3 is a plane view showing the crane of FIG. 1 adapted to the dotted line position, at the right of FIG. 2;

FIG. 4 is a side elevation of the chassis of the crane shown in FIG. 1 including a drivers cab;

FIG. 5 is a section on line V-V of FIG. 3;

FIG. 6 is an enlarged perspective view of a universal joint;

FIG. 7 is an enlarged top view of a gimbal joint;

FIG. 8 is a section on line VIII--VIII of FIG. 7;

FIG. 9 is a perspective view of a wheel chock; and

FIGS. 10 and 1l are side elevations similar to FIG. 1, showing the crane in different stages of knock-down for transport.

The principal components of the crane shown in FIG. 1 are: a wheeled chassis 1; front and

rear booms

2 and 3; a truss 4; a front crane trolley 6 mounting a front pair of grapple arms 7 and 8 (FIG. 5); and a rear crane trolley 9 mounting a rear pair of grapple arms 11 and 12 (FIG. 2); the trolleys and associated grapple arms affording semi-trailer or load grasping means operatively mounted on the truss.

The Wheeled chassis 1 (FIG. 3 and 4) comprises a longitudinal center beam 13 mounting transverse frame beams 14, 16 at its opposite ends. A forward pair of steerable, individually powered front wheels 17, 18 and a rearward pair of steerable, individually powered rear wheels 19, 21 are mounted respectively, on transverse front and rear axle beams 22, 23 secured to the center beam 13. Also secured to the center beam 13 are horizontal front and rear platforms 24, 26 on which a semi-trailer or cargo -box may be supported for transport by the crane, as shown in FIG. 1 and as will be explained more fully herein below.

Rigidly secured to and extending upwardly from the front and rear ends of the center beam 13 are front and rear bracket assemblies 27, 28, each presenting a pair of boom mounting lugs 29 and 31.

The front and

rear booms

2 and 3 are operatively mounted on the front and rear bracket assemblies 27 and 28, respectively, for pivotal adjustment independently of each other about a fore and aft extending, generally horizontal axis which is determined by front and rear pivot pins 32 and 33 (FIG. l).

A lower section 34 of the front boom 2 has depending front and rear lugs which are fitted, respectively, between the front and rear boom mounting lugs 29, 31 and are connected thereto by the pivot pin 32.

An upper section 36 of the front boom 2 is hingedly connected to the lower boom section 34 of a transverse axis 37 which is spaced upwardly from the fore and aft extending axis of the pivot pins 32, 33. Abutting anges of the lower and upper boom sections 34, 36 are separably connected by bolts 38 for releasably securing the upper boom section against pivotal movement about the transverse axis 37.

The foregoing explanations regarding the mounting and construction of the front boom 2 analogously apply to the rear boom 3. That is, the rear boom has a lower section 34' and an upper section 36 which are hinged together on a transverse axis 37' and are releasably locked together by bolts 38. Depending lugs of the lower boom section; 34' are fitted between the lugs 29, 31 of the rear bracket assembly 28, and the pivot pin 33 connects the assembled rear boom 3 to the bracket assembly 28 for swinging movement on the same longitudinal horizontal axis on which the assembled front boom 2 is connected with the bracket assembly 27 by the pivot pin 32.

Referring to FIG. 2, a double acting hydraulic ram 39 is pivoted at its barrel end on an upright bracket 41 at one end of the rear transverse frame-beam 16, and another double acting hydraulic ram 42 is similarly pivoted on an upright bracket 43 at the other end of the beam 16. The piston rods of the rams 39, 42 are pivotally connected with the boom 3 at radial distances from the pivot pin 33, a transverse bar 44 secured to the lower boom section 34 mounting pivot pins for the piston rods of the rams 39, 42. Contraction of the ram 39 and simultaneous expansion of the ram 42 swings the boom 3 to the laterally inclined position at one side of the vehicle frame in which it is shown in full lines in FIG. 2; and conversely, expansion of the ram 39 and simultaneous contraction of the rarn 42 swings the boom 3 to the laterally inclined position at the other side of the vehicle frame in which it is shown in dotted lines at the right of FIG. 2. Adjustment of the rams 39 and 42 to equal lengths swings the boom 3 to an upright center position, as indicated in dotted lines in FIG. 2.

The front boom 2 is swingable to laterally inclined positions at opposite sides of the vehicle frame and to an upright center position in the same manner as explained herein before and shown in FIG. 2 with reference to the rear boom 3. The tilting rams 42, 42 for the rear and front booms are show broken away in FIG. l at the near side of the vehicle frame, and the companion ram 39 for the rear boom and a corresponding companion ram, shown, for the front boom are similarly arranged at the far side of the vehicle frame.

The truss 4 is of lattice type construction and has front and rear ends adjacent, respectively, to the front and

rear booms

2 and 3. The width of the truss, as shown in FIG. 3, is uniform from end to end. Its height, as shown in FIG. l, is also uniform throughout its length, except for short upwardly tapering portions at its longitudinally opposite ends. The mid section of the truss between the tapered end sections is of rectangular cross section and, as shown in FIG. 5, includes a pair of tubular

top beams

44, 46, and a pair of tubular bottom beams 47, 48.

Front and rear double acting hydraulic hoist

rams

49 and 51 swingably suspend the truss 4 at its front and rear ends from the front and

rear booms

2 and 3 in up and down adjustable relation thereto.

The front hoist ram 49 is connected with the free end of the front boom 2 for universal swinging movement as illustrated in detail in FIG. 6. A bearing sleeve 52 is secured in a bore of the upper boorn section 36, as by Welding, and mounts a swivel pin 53 which projects horizontally inward from the boom 2. The piston rod 54 of the hoist ram 49 has a forked end which is pivotally connected with the swivel pin 53 on an axis at right angles to the pivot axis of the latter by a pin 56.

The cylinder 57 of the front hoist ram 49 has a flexible supporting connection with the forward end of the truss 4, the connection being afforded by a girnbal joint 58 which is shown in detail in FIGS. 7 and 8. A first pair of axially alined trunnions S9, 61 of the girnbal joint are formed on an octagonal collar 62 which in the assembled condition of the joint is surrounded by a knuckle block 63. The collar 62 surrounds the ram cylinder 57 intermediate its ends as shown in FIG. 11, and it is rigidly secured thereto as by welding. The trunnions 59, 61 are surrounded by bearing sleeves, and opposite side members 64, 66 of the knuckle block 63 have bottom anges on which the sleeves may rest in order to support the collar 62 and cylinder 57 on the knuckle block. The side member 64 has a fixed abutment 67 and a withdrawable stop pin 68 in straddling engagement with the trunnion 59 bushing, and the side member 66 of the knuckle block 63 similarly has a xed abutment 69 and a withdrawable stop pin 71 in straddling engagement with the trunnion 61 bushing.

When the stop pins 68, 71 are removed the collar 62 and its associated cylinder 57 may be disengaged from the knuckle block 63 by rotation of the cylinder S7 on its axis through an angle of about 45 degrees in anti-clockwise direction as viewed in FIG. 7. Conversely, the joint may be reassembled by moving the cylinder S7 axially into the knuckle block with the axis of the trunnion blocks extending about diagonally of the block as indicated by the dash-dotted line 70 in FIG. 7, and by then rotating the cylinder clockwise so as to reengage the trunnion bushings with the bottom flanges and abutments 67, 69 of the side members 64, 66. Thereafter, the stop pins 68, 71 are reinserted to retain the collar 62 and knuckle block 63 is assembled condition.

A second pair of

axially trunnions

72, 73 of the girnbal joint 58 are rigidly mounted in transverse frame beams 74, 7 at the forward end of the truss 4. The

trunnions

72, 73 are secured in position on the frame beams 74, 76 by vertical pins 77, 78, respectively, and they project into the knuckle block 63 from opposite sides in the longitudinal direction of the truss 4. Spherical bearings 79 and 81 universally connect the knuckle block 63 with the fixed trunnions 72 and 73, respectively.

The foregoing explanations with respect to the front hoist ram 49 and its connections with the front boom 2 and with the front end of the truss 4 analogously apply to the rear hoist ram 51 and its connections with the rear boom 3 and with the rear end of the truss 4. A universal jointY 52-56 corresponding to the universal joint 5256 connects the piston rod of the rear hoist ram 51 with the free end of the rear boom 3, and a gimbal joint 58 corresponding to the gimbal joint 58 provides a flexible supporting connection between the cylinder of the rear hoist ram 51 and the rear end of the truss 4.

As best shown in FIG. 3, a pair of front guide wings 82, 83 extend from laterally opposite sides of the truss 4 at its forward end in cooperative relation to the front boom 2. Likewise, a pair of rear guide Wings 84, 86 corresponding to the front guide wings 82, 83, extend from laterally opposite sides of the truss 4 at its rear end in cooperative relation to the rear boom 3. The purpose of the front and rear guide wings is to prevent the truss 4 from swinging lengthwise forwardly across the front boom 2 or rearwardly across the rear boom 3, while the booms are swung in one direction or the other on the common horizontal axis of the pins 32, 33.

The :front crane trolley 6 comprises a frame which surrounds the truss 4 and is supported thereon for sliding movement in lengthwise opposite directions. Angle iron members 87, 88 (FIG. 5) at opposite sides, respectively, of the trolley have horizontal anges overlying the

top beams

44 and 46 of the truss, and a cross tube 89 underlying the truss 4 is connected with depending anges of the angle irons 87, 88 by brace assemblies 91 and 92. A double acting hydraulic shift ram 93 for the trolley 6 is connected at its barrel end with a bracket 94 at the upper side of the trolley, and the piston rod of the shift ram 93 is detachably connected with a bracket 96 at the upper side of the truss 4. Contraction of the shift ram 93 moves the trolley 6 to its forward end position on the truss in which it is shown in FIG. l, and expansion of the shift ram 93 moves the trolley to its rearward end position in which it is shown in FIGS. l* and 11.

The cross tube 89 of the trolley 6 shiftably supports the forward grapple arms 7 and 8 for translatory horizontal movement toward and away from each other; and the cross tube 89 also supports the grapple arms 7 and 8 for pivotal movement at right angles to their translatory movement. In order to provide for such translatory and pivotal movement of the grapple arms, elongated tubular side journals 97, 98 (FIG. 5) are connected, respectively, to the grapple arms at their upper ends, and are telescopically and rotatably supported within the opposite end portions of the tube 89.

Actuating means for the grapple arm 7 comprise a double acting hydraulic shift ra-m 99 within the cross tube 89, and a double acting hydraulic swing ram 101 at the same side of the trolley 6 as the grapple arm 7.

The shift ram 99 is anchored at its barrel end on a vertical pin within the tube 89 adjacent the longitudinal vertical mid plane of the truss, and the piston rod of the ram is connected to the inner end of the journal 97. Contraction of the ram 99 adjusts the grapple arm 7 to its limit of translatory inward -movement as shown in full lines in FIG. 5, and expansion of the ram 99 adjusts the grapple arm 7 to its limit of translatory outward movement as shown in dotted lines in FIG. 5.

Th swing ram 101 is universally connected at its barrel end with a bracket arm 102 of the brace assembly 91, and the piston rod of the swing ram is universally connected with the grapple arm 7 at a radial distance from the axis of the tubular journal 97. Contraction of the swing ram 101 lowers the grapple arm 7 to the vertical position in which it is shown in FIG. 1 irrespective of the lateral position to which the grapple arm is adjusted by the shift ram 99. Conversely, expansion of the swing ram 101 raises the grapple arm 7 to the approximately horizontal position in which it is shown in FIG. 10, re-

gardless of its lateral adjustment by the shift ram 99.

A shift ram 103 corresponding to the shift ram 99, and a swing ram 104 corresponding to the swing ram 101 are connected to the tubular journal 98 and to the grapple arm 8 for translatory shifting and vertical swinging of the latter relative to the crane trolley 6, the same as vthe grapple arm 7.

The foregoing explanations with respect to the front trolley 6 analogously apply to the rear trolley 9. A shift ram 93 is connected at its opposite ends to brackets 94 and v96 on the rear trolley frame and on the truss 4, for shifting the rear trolley 9 back and forth longitudinally of the truss. A cross tube 89' of the rear trolley frame mounts tubular trunnions 97', 98 on the grapple arms 11 and 12, respectively; and a pair of shift rams, not shown but corresponding to the shift rams 99, 103, are mounted within the tube 89 for adjusting the grapple arms 11 and 12 by translatory movement toward and away from each other. Swing rams 101 and 104', corresponding to the swing rams 101 and 104, are connected with the rear grapple arms 11 and 12, respectively, for raising and lowering them, the same as the front grapple arms 7 and 8.

FIG. 1 shows a semi-trailer 106 suspended from the truss 4 by the front and rear pairs of grapple arms, and sustained above the front and rear platforms 24, V26 of the vehicle frame by the contracted front and rear hoist rams 49 and 51. For transport purposes the trailer may be set down upon the platforms 24, 26, as indicated in dotted lines in FIG. 1, by expansion of the front and rear hoist rams 49, S1. The platform 24 is equipped with a wheel chock mechanism 107 for blocking the trailer running 108 so that the trailer will be prevented from rolling forward or backward on the platforms 24, 26 while the crane is moved on its propelling

wheels

17, 148 and 19, 21.

As shown in FIG. 9, the wheel chock mechanism 107 comprises two relatively reciprocable sections, one having parallel side beams 1048, 109, a wheel blocking beam 111 and an angle iron connecting bar 112; and the other having parallel side beams 113, =114, a wheel blocking beam 116 land an angle iron connecting bar 117. In the installed condition of the wheel chock sections on the platform 24 the Iwheel blocking beams 111, 116 and the bars 112, 117 rest on top of the platform; the side beams 108, 113 are in sliding engagement with a guide slot 118 which extends longitudinally of the platform at one side of the frame center beam 13; and the side beams 109, 114 are in sliding engagement with a guide slot 119 which extends parallel to the guide slot ,118 at the other side of the frame center beam 13. The wheel blocking beams 111 and 116 are thus slidably mounted on the platform in transversely extending, fore yand aft movable relation thereto and at a variable spacing from each other. A double acting hydraulic ram 121 is disposed below the platform and is connected at its cylinder end with the wheel blocking beam 11-6 and at its rod end with the wheel blocking beam 1.11.

Preparatory to lowering of the trailer 106 upon the platforms 24, 26 the wheel chocking ram 121 is fully extended so that the blocking lbeams 113, 114 'will be spaced a maximum distance from each other. When the wheels of the trailer running gear 108 have come to rest on the platform 24, and the trailer landing gear 122 has come to rest on the platform 26, the chocking ram 121 is contracted and the blocking bars 111, 116 will then floatngly adjust themselves into cooperative engagement lwith the wheels of the trailer running gear 108. The running gear wheels will thus be prevented from rolling either forward or backward on the platform 24, and longitudinal shifting of the trailer on the crane chassis will thus be prevented.

The rear platform 26 is equipped with a wheel chocking mechanism 107' which is a duplicate lof the wheel chocking mechanism 107 of the front platform 24. The rear chocking mechanism 107 may be used to block the running gear of a trailer whose position on the platform is reversed with respect to the trailer position as shoiwn in FIG. l.

FIG. 2 shows `a pair of Outrigger arms 1123 and 124 at the rear end of the vehicle frame, and a corresponding pair of Outrigger arms 123" and 124 (FIG. 3) are mounted on the forward end of the vehicle frame. The Outrigger arm 123 is pivoted on the lower end of the frame bracket 41, `and a hydraulic ram 126 on the frame bracket 43 is operable to swing the arm 123 up and down about its pivot connection with the bracket 41. The arm 123 is further telescopically contractable and extendable by an internal hydraulic ram not shown. The Outrigger arm 124, and the forward `Outrigger arms 123 and 124 are constructed and operable in a'manner corresponding to that of the Outrigger arm :123.

FIGS. 3 and 4 show `an internal combustion engine 127 and an associated hydraulic pump assembly 128 mounted on the center beam 13 of the yvehicle frame. A hydraulic circuit, not shown, connects the pump assembly with a control station 129 (FIG. 3) in an operators cab 131 at the forward end of the vehicle frame, and with the various hydraulic actuating mechanisms of the crane including hydraulic drive motors, not shown, for the supporting

wheels

17, 18, 19, 21, hydraulic steering rams 132, 133, and the boom tilting rams, hoist rams, trolley shift rams, grapple arm shift rams, grapple arm swing rams, and wheel chocking rams.

When the crane is pulled up alongside `a railroad track 134, as shown in FIG. 2, the

outriggers

124, 124 are extended to bear on the rail next to the crane, and the outriggers 123, 123 are extended to bear upon the road at the other side of the crane. The front and rear pairs of grapple arms are adjusted to their widest transverse spacings and to their raised positions on the trolleys 6 and 9. The front and rear booms may then be swung to the dotted line position at the right of FIG. 2 so as to bring the truss 4 and front and rear trolleys 6 and 9 over a semi-trailer rwaiting to be loaded upon a flat car 136 on the track 13-4. The grapple arms are then dropped to their vertical positions on the trolleys 6 and 9, and the trolleys are shifted lengthwise of the truss to positions adjacent the front and rear ends, respectively, of the trailer box. The hoist rams 49, 51 are then operated, if necessary, to bring the pivoted retainer shoes 137 at the lower ends of the grapple arms to the level at which they will engage the longitudinal bottom edges of the trailer box when the shift rams for the grapple arms are operated to move the grapple arms against the opposite sides of the trailer box. The hoist rams 49, 51 are then operated to lift the trailer from the road, and the boom tilting rams are operated to swing the lifted trailer over the at car 136 as shown in full lines at the left of FIG. 2. The hoist rams are then operated to lower the trailer on the at car, the front and rear pairs of grapple arms are spread apart to disengage the retainer shoes 137 from the trailer box, and the spread apart grapple arms are swung upward so that they will clear the trailer box when the booms are subsequently swung back toward the road side of the crane chassis.

In order to unload a trailer from the iiat car upon the road the described loading operation may be reversed. It will also be apparent that instead of a semi-trailer including running and landing gear, a cargo box may be similarly loaded upon or unloaded from the liat car.

The hydraulic circuit for the boom tilting rams is so arranged that an operator at the control station 129 may swing the booms about their common horizontal pivot axis independently of each other. To do so will be helpful for the proper handling of a trailer or cargo box in case the crane chassis should stand on the road in an oblique position relative to the railroad track, or the trailer or cargo box to be transferred should stand in an oblique position relative to the crane chassis. The universal suspension of the hoist rams 49, 51 from the

boOmS

2 and 3, and the flexibility 0f the gimbal joints 58, 58' will readily accommodate any differential pivoting of the booms for the purpose of compensating oblique positioning of the crane chassis relative to the railroad track or relative to the trailer or cargo box to be transferred.

Referring to FIGS. l() nd 11, the crane may be knocked down into a compact unit for shipment by rst lowering the truss `4 to the position shown in FIG. l0; then detaching the hoist rams 49, 51 from the gimbal joints 58, 58 and repinuing bottom extensions of the hoist ram cylinders to the

lug

96, 96 of the truss as shown in dotted lines in FIG. l0 while the truss is temporarily sustained on the

booms

2 and 3 by

withdrawable locking pins

138, 139 then extending the repinned hoist rams as shown in FIG. ll so as to lower the truss and crane trolleys upon the crane chassis; and finally folding the

upper boom sections

36, 36 into the dotted line positions shown in FIG. ll after the connecting bolts 38, 38' between the upper and lower boom sections have been removed.

In order to re-erect the crane from the knocked down condition, the repinned hoist rams 49, 51 may be expanded so as to tilt the

upper boom sections

36, 36 about their transverse pivot axes 37, 37 back into vertical positions the connecting bolts 38, 38 are then reinstalled; the truss is lifted by contraction of the hoist rams to the position shown in FIG. 10, and temporarily locked to the erected booms by the

pins

138, 139; the hoist rams are then disconnected from the

truss brackets

96, 96 and in cOntracted condition swung back over the gimbal joints 58, 58. Expansion of the contracted hoist rams then lowers the hoist ram cylinders throu-gh the knuckle blocks of the gimbal joints, and subsequent rotation of the expanded hoist ram cylinders will recouple the trunnions 59, 61 with the respective knuckle block. The locking pins 138, 139 are then withdrawn to release the truss for up and down adjustment by the hoist rams.

I claim:

1. A mobile crane comprising, a wheeled vehicle frame; front and rear booms operatively mounted on said vehicle frame for pivotal adjustment about a fore and aft extending, generally horizontal axis; hoist rams swingably suspended, respectively, from said booms; a truss connected with said rams for up and down movement thereby relative to said booms; front and rear crane trolleys mounted on said truss for back and forth travel lengthwise thereof; front and rear pairs of grapple arms operatively mounted, respectively, on said trolleys for movement therewith lengthwise of said truss; a pair of front guide wings extending from laterally opposite sides of said truss in cooperative relation to said front boom; and a pair of rear guide wings extending laterally from opposite sides of said truss in cooperative relation to said rear boom.

2. A mobile crane for transferring semi-trailers from the road to railroad ilat cars and vice versa, comprising a wheeled vehicle frame; front and rear booms pivotally mounted on said frame for swinging movement to pickup positions at either side thereof; hoist rams swingably suspended, respectively, from said booms; a truss connected with said rams for up and down movement thereby relative to said booms; front and rear crane trolleys mounted on said truss for back and forth travel lengthwise thereof; front and rear pairs of grapple arms operatively mounted, respectively, on said trolleys for moyement therewith lengthwise of said truss; and a wheel chock mechanism for a semi-trailer positioned for transport on said vehcile frame, said chock mechanism comprising a pair of parallel beams slidably mounted on said vehicle frame in transversely extending fore and aft movable relation thereto, and a hydraulic ram connected at its cylinder end with one of said -beams and at its rod end with the other.

3. A crane as set forth in claim 2 wherein said wheel chock mechanism is mounted at one end of said vehicle frame, and wherein a duplicate of said wheel chock mechanism is mounted at the other end of said vehicle frame.

4. A mobile crane comprising, a wheeled vehicle frame; front and rear booms operatively mounted on said vevehicle frame for pivotal adjustment about a fore and aft extending, generally horizontal axis; a truss having front and rear ends adjacent, respectively, to said front and rear booms; front and rear hoist rams for said truss, each comprising a cylinder and associated piston rod; gimbal joints at said front and rear ends of said truss for connecting the latter with the cylinders of said front and rear hoist rams, respectively; means connecting the piston rods of said hoist rams with the free ends of said booms in universally swingable relation thereto; front and rear crane trolleys mounted on said truss for back and forth travel lengthwise thereof; and front and rear pairs of grapple arms operatively mounted, respectively, on said trolleys for movement therewith lengthwise of said truss.

v5. A mobile crane comprising, a wheeled vehicle frame; front and rear booms operatively mounted on said vehicle frame for pivotal adjutsment about a fore and aft extending, generally horizontal axis and each being hinged intermediate its ends on a transverse axis spaced upwardly from said fore and aft extending axis so that an upper section of each boom may be folded downward and toward the other boom on an associated lower boom section; separable connecting means between said upper and lower sections of each boom for releasably maintaining said upper section thereof upright on its associated lower section; a truss having front and rear ends adjacent, respectively, to said front and rear booms; front and rear hoist rams swingably suspending said truss at said front and rear ends thereof from said front and rear booms, respectively, in up and down adjustable relation thereto; front and rear crane trolleys mounted on said truss for back and forth travel lengthwise thereof; and front and rear pairs of grapple arms operatively mounted, respectively, on said trolleys for movement therewith lengthwise of said truss.

6. A crane as set forth in claim 5 and further cornprising front and rear upper pivot means swingably connecting the piston rods of said front and rear hoist rams, respectively, with the upper sections of said front and rear booms; flexible upper supporting connections between the cylinders of said front and rear hoist rams and the front and rear ends, respectively, of said truss; each of said flexible connections being separable for disconnection of said front and rear hoist rams from said trus; separable locking means operatively associated with said front and rear booms and said truss for supporting the latter on said booms independently of said hoist rams; and separable pivot means operatively associated with the lower ends of said hoist ram cylinders and with said truss for supporting the latter on said booms independently of said locking means.

References Cited UNITED STATES PATENTS 3,174,630 3/ 1965 Tantlinger et al. 3,251,496 5/ 1966 Lamer et al. 2,773,614 12/1956 Edward et al. 2,941,678 6/ 1960 Keys 214--77 2,995,263 8/1961 Fitch 214-731 2,996,206 8/ 1961 McKee 2.14--75 3,233,759 271966 Turturro et al 214-- FOREIGN PATENTS 1,025,407 4/ 1953 France.

181,253 6/1966 U.S.S.R.

GERALD M. FORLENZA, Prmary Examiner.

R. B. JOHNSON, Assistant Examiner.`

U.S. Cl. X.R. 212-8; 214-38, 77