US2394217A - Portable crane - Google Patents

Description

J. E. TOM P'ORTABLE CRANE Feb. .5, 1946.

Filed Jan. 22', 1944 2 sheets-sheet 1 Patented Feb. 5, 1946 UN I TED STAT ES PATE NT OF F IC E PORTABLE GRANE John E. Tom, Cleveland; Ghio 'Application January 22, 1944, Serial No.v 519,325-

7 Claims.

This invention relates broadly to cranes; and more speciiically tov cranes o1?.l the typev that are designed` for use and operationy in conjunction with power`- driven vehicles.`

' Oneof the' objects of the invention is to providelinkage:y associated' withi the boomV Yto eifect horizontal'fmovementsof- 'the' load beyond the centercf gravitythereof' in order to accommodateloading operations in such environs as require the projection of the load throughl a side Wall opening or the:V deposit: thereof upon a: piatfornndisposed'ibeyond; the: vertical swing of' the,Y boom.

l`Another object of the' invention is` to provide afhoistmechani'sm on the chassis frame of the crane which isv arrangedv for operation from; the winch or power takefoff `on thek vehicle.

Another objectfof the' invention is vto provide a platfon'n on; the boom of the:l crane to accommodate the support of workmen in contiguous; relation with thefsuspendedload iny order 'to xfacilitate manipulation thereof or service lattendant4 the procedure:- of installation and repair. Another objectof theinvention is to construct a, coupling between. the craneand the vehicle withywhich it is associated:A so thatr only a fractional part of the weight of the crane will be borne'. by' the vehicle andv none ofA the load will beimposed-g-upon. the vehicularsprings.

`Another object yofv the" 'invention is' to provide' asteeringmechanism for thec'rane-chassis which is. operable independent. ofV the vehicle Asteering' gear.

Another object of the invention is to provide aboonr which is adapted rfor adjustmentiny a substantially horizontal plane to facilitate negotiation of highway underpasses, towing of the assembly: at relatively highA ratesof speedand storage of; the crane within: buildings otorthodox construction.

'Another object or the invention is' to4 provide mechanismv for: oscillating theVA boom- 'inf a. horizon/tal plaine aboutfan axis normal to the chassis frame-therefon i '-Another dbi ectf of@ the invention is to provide independently'operablev jacks for each ofthe wheelstovfacilitateadjnstments of the chassis compensative with" ground inclina-tions or irregularities..

y*Another object of the. invention is tov construct azcranehaving the component parts thereof free from crossf 'members orlarge protrusi'ons so that the crane. whendismantled', may be readilyA handied whiley in: transit.

Another object of the inventionis to-provide a: connection between vthe cranewand. vehicle which will accommodate. limited independent movement thereof. y

Another object ofthefinvention is to provide alreadily` detachable cable.V connection between the. crane differentialwinch andthe power. driven winch on thevehicle.

Further objects. of the inventionv reside inv a cranewl'iich-is designed to-meet the recluirem er1tsA of deck and aircraft loading, alstructure` which is light and durable'and afmechanisrn which is econo-mic of-l manufacture and assembly.

@ther objects and advantages more or less-ancillaryftofthe foregoing and the manner in which all'the various objects are realizedY will appear in the following description, which considered inv connection with theaccompanying drawings,y setsV forth thefpreferred embodiment of the in.- vention.

In the drawings wherein preferred embodiments: or 'the invention are illustrated:

Fig. 1 isa-side` elevational 'view' of the iin-- proved cranev includingone ofthe typesof vehicles vthat mayv bev used therewith;

Fig.` 2. isf-a iront elevational View of the crane illustrated in Fig. 1v; A

Fig. 3/ is a. plan` View of the crane showingin dotted. lines, the forward endof. the boom lever inits lateralr actuated positions; `and Fig. 4 isa plan view of a fragmentary portion. of.A the crane deck plate and theswiVel mechanism. associated therewith.

Referring iirst tov Fig. l, the crane comprises a` chassis` frame Ill, embodying side rails II,"a.n axler I2v of conventional automotivedesign, wheels I3 mounted thereon and cross members I4 uniting the. side rails of' theY frame. The upper face of the frame isprovided with a deck plate I5. fulcrumed upon a pin I6 mounted in the forward cross member III. The 'rearwardportion of the plate. is providedv with a mast I'I formed of uprights I8 connected" at, their uppery ends with a gusset'. plate supportingla sheave I9 anda pair of linksV or Stay bars 2i); The boom ZI comprises a pair of channel irons ,22" secured at their lower ends. to a cross railv 23 which is secured in turn to side braces 2`ll"fulcrumed in brackets 25'mountedpuponI the forward endr of the plate I5. '.I'he upper end off theboom Yis formed with a forwardly disposedv extension '26' drilled for the reception of a pin 2'1 having a. lever 28 and sheav'e 2S mounted thereon. The 'forward end ofthe lever is provided with a. sheave 30 for the supporter the load carrying" cable 'SI'. 'The linner portion ofthe cable 3l' .i's' trained Vover the sheaves 29 and 32 andaround a small drum 33a on a winch 33 mounted on the chassis frame. The winch 33 is further provided with a large drum 33h adapted to receive the free end of the cable 34 from the power winch 35 on the vehicle 3B. In the event the power output of the vehicular winch or the running speed of the cable 3| is inadequate the diameter of the drum 33 may be increased relative to the diameter of the winch to produce the desired mechanical advantage.

The rearward end of the lever 28 is coupled with the stay bars or links 20 which are of a suitable length to maintain the forward end of the lever 28 in a substantially horizontal position when the boom is raised or lowered. Vertical adjustments of the boom are effected through a manually operable winch 38 mounted on the mast l5, the winch being provided with a cable se trained over the sheave I9 and anchored in a bracket mounted on the upper end of the boom.

' The forward face of the boom is provided with a platform 40 to accommodate access to the load for the purpose of adjustment, such for example as required in the securement of a replacement engine in an airplane, the installation of a propeller, or the assembly of astructural element with the component part therefor. The platform is preferably hinged upon a carriage 42 supported upon rollers 43 which are guided in the channel irons 22. Vertical adjustment of the carriage may be effected by a chain fall 44 mounted on a shaft adjacent the top of the boom having spools 45 thereon coupled through cables 46 to the carriage 42. Cross bars or rungs 4l are secured to the rearward face of the channels 22 to form a ladder and a guard rail 48 is provided on the platform for the safety and convenience of the workmen. The platform is retained in a horizontal position, irrespective the inclination of the boom by adjustment of the chain 49.

The axle i2 is formed with steering knuckles, a drag link and a steering gear of conventional form coupled in the usual manner with a steering column 50 so that the crane assembly may be readily handled in transit and accurately spotted for the loading operation,

The chassis frame l0 is mounted upon jacks 5l pivotally connected with the axle l2 and held against lateral movement by a pintle 52 having a ball end thereon guided in a housing 53 in the center of the axle. The jacks may be of the hydraulic self contained type adapted for manual operation. through the medium of a pump constituting a part of the unitary structure. The axle is further braced against lateral movement by the rods 54 mounted for vertical pivotal movement on both the axle and frame. The frame leveling mechanism embodied in the improved crane aifords not only a means of shifting the center of gravity of thersuperstructure when it is necessary or convenient to use the crane on uneven ground but also affords a means of relieving the torsion on the side rails of the crane when the ground on one side of the vehicle is higher than that of the other.

As shown herein, the crane is coupled with a tractor through spherical ended pintles mounted on plates 55 bolted to the frame of the vehicle adjacent the center thereof and above the bogie or spring supported elements therein. It will be understood that other type of vehicles than the tractor illustrated herein may be employed in combination with the improved crane and that such combinations are contemplated as falling within the scope and spirit of the present invention.

The rearward end of the deck plate i 5 is retained against vertical movement by an angle iron 56 of arcuate form supported by brackets 51 mounted on the cross rail i4 and disposed to overlie the upper face of the rear edge of the plate. The lower face of the plate is provided with a lug 58 engaged with nuts or collars 59 mounted on a shaft 6I! threaded in a bearing block 6l secured' to 'one of the side rails Il. The outer end of the shaft 59 is formed with a hand crank 62 to facilitate rotation of the shaft and in turn oscillation of the plate, boom, mast and other mechanism mounted thereon. The rotational adjustment attained through the structure described above is intended primarily to facilitate lateral movements of the boom when it is desired to place the load with nicety upon a given spot and without alteration of the position of the vehicle.

In operation, after .the crane is pushed or towed into proximity with the load, the boom is elevated to position, the lever 28 slightly above the floor level of the cargo carrier. The cable 3l is next aiiixed to the load sling and the vehicular winch 35 then operated through the clutch and control mechanisms 63 to eiect the elevation of the load. The boom is next lowered through manipulation of the winch 38, the links 20 restraining movement of the rearward end of the lever 23 during this operation and effectinga substantially lineal movement of `the load.

When the crane is moved any substantial distance the links 20 may be released, the platform collapsed, and the boom lowered to the position indicated by dotted lines in Fig. 1.

n One of the utilities of the improved crane (but not the only one) resides in the use thereof in loading cargo airplanes, and/or elevating renewal'elements therefor or removing heavy parts therefrom. In such environs the machine elements may be safely handled and accurately positioned with a minimum of labor and the motor mechanic on the platform 40 thus relieved of the hazardous task of shifting or lifting the load.

Although the foregoing description is necessarily of a detailed character, in order that the invention maybe completely set forth, it is to be understood that the specific terminology is not intended to be restrictive or conning, and that various rearrangements of parts and modiiications of detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

I claim:

l. In combination with a tractor having a power operated winch thereon, a portable crane comprising a frame pivotally connected at one end thereof to said tractor, wheels on said frame adjacent the opposed end thereof, a boom pivoted upon said frame superjacent said wheels, a lever pivoted in the center thereof upon the free end of said boom, links pivotally 'connected with one end of said lever and with said frame, a load carrying cable coupled with the winch on said tractor and overrunning the opposed end of said lever, a winch on said frame, a cable operatively connected thereto and with said boom, parallel beams embodied in said boom, rollers engaged therewith, a, platform carried by said rollers, and a cable supported by said boom and coupled with said platform to facilitate adjustments thereof. 1

2. In combination with a tractor having a power actuated winch thereon, a portable crane comprising a frame pivotally connected at one end thereof to the central portion of the tractor, an axle mounted upon the opposed end of said frame, wheels on said axle, a steering gear on said frame operatively connected with said wheels, hydraulic jacks intermediate said frame and said wheels, a pivotal connection between said frame and the central portion of said axle, a boom pivoted upon the forward end of said frame, a lever pivoted intermediate its ends to the free end of said boom, a mast on said frame rearward said boom, links pivotal thereto and with the inner end of said lever, a drum mounted on said mast, a sheave wheel mounted upon the opposed end of said lever, a cable trained thereover, and about said drum and the winch on said tractor, a second winch on said mast, a cable wound thereover and connected with the top of said boom and a platform mounted on the forward face of said boom and adapted for adjustment throughout the length thereof.

3. In combination with a motor vehicle having a power operated winch thereon, a crane comprising a frame, wheels mounted thereon adjacent the forward end thereof, means on said frame for steering said wheels, pivotal connections on said frame coupled with the vehicle at the center of gravity thereof, a boom pivoted upon said frame superjacent said wheels, a lever pivoted at its center upon the free end of said boom, means for raising and lowering said boom, links connecting one end of said lever with said frame rearward said wheel, a load carrying cable operatively supported upon the opposed end of said lever and connected with the winch on the vehicle, the length of said links and the portion of the lever connected thereto being proportioned relative to the length of the boom to delimit vertical movement of the end of said cable when the boom is lowered and to bias a portion of the load through the medium of the link upon the frame rearward the vehicle wheels.

4. In combination with a motor vehicle having a power operated winch thereon, a crane comprising a frame, wheels mounted thereon adjacent the forward end thereof, a steering gear on said frame operatively connected with said wheels, ball joint pivots on said frame coupled with the vehicle adjacent the center of gravity thereof, a boom pivoted upon said frame superjacent said wheels, mechanism associated with said boom for moving the load carried by said boom horizontally without substantial change in the elevation thereof, means for raising and lowering the load carried by said boom, means for rotating said boom and independently operable jacks adjacent for moving a load carried thereby forwardly' the wheels on said frame for tilting the boom laterally.

5. In combination with a crawler type tractor embodying a power operated winch, a portable crane comprising a frame, wheels onone end thereof, ball joint connections between the opposed end of the frame and said tractor intermediate the ends thereof, a plate pivotally mounted on said frame, a boom mounted thereon over said wheels, means for raising and lowering said boom, mechanism for horizontal translation of the load without material vertical movement thereof, a load carrying cable on said boom, a winch on said plate, a small drum on said winch having said cable wound thereon, a large drum on said winch and a second cable wound about said large drum and connected with the power op` erated winch on the tractor.

6. In combination with a motor vehicle embodying a steering mechanism and a power-operated winch, a crane comprising a frame, a boom mounted thereon, mechanism for rotating said boom, mechanism for raising and lowering said boom, mechanism for moving a load suspended on said boom forwardly without material change in the elevation thereof, a load lifting cable on said boom controlled by said winch, an axle on said frame subjacent said boom, a pair of road wheels thereon, mechanism on said frame for steering said wheels, independently operable jacks intermediate each wheel and the frame, universal couplings between said frame and the vehicle, whereby said crane may be pushed directionally towards a loading station, steered into loading position independent the vehicle steering mechanism, leveled for operative manipulation of the boom, rotated to position and the load elevated and projected through a cargo receiving opening in a carrier without further movement of the vehicle.

7. In combination with a motor vehicle embodying a steering mechanism, a crane comprising a frame, a boom thereon, mechanism thereon without material change in the elevation thereof, universal couplings supporting said frame forwardly of said vehicle, an axle on the forward portion of said frame below said boom, wheels on said axle, a steering gear on said frame for the control of said wheels, and means for tilting said frame relative to said axle, whereby said crane may be pushed by said vehicle in the direction of a loading station, independently steered into loading position, and the boom tilted to effect the discharge of the load while elevated without manipulation of the vehicle.

JOHN E. TOM.

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