US3362544A - Wheel-supported heavy load crane - Google Patents

Description

Jan. 9, 1968 w. WELLNITZ WHEEL-SUPPORTED HEAVY LOAD CRANE Filed April ll, 1966 ,tv Sim United States Patent O 3,362,544 WHEEL-SUPPORTED HEAVY LOAD CRANE Willi Wellnitz, Grafschaft, Germany, assignor to Beteiligungsund Patentverwaltungsgesellschaft mit heschrankter Haftung, Essen, Germany Filed Apr. 11, 1966, Ser. No. 541,758 Claims priority, application Germany, Apr. 29, 1965,

B 8 Claims. (Cl. 212-49) ABSCT F THE DHSCLOSURE The present invention relates to a heavy load crane supported by a carriage and adapted to be pulled by a motor vehicle, and is characterized primarily in that the carriage supports a torsion resistant base body carrying rotatable crane means including platform means and boom means detachably pivotally connected to said platform means while the height of said 4base lbody is a multiple of the height of said platform means, supporting leg means being pivotaoly connected to oppositely located portions of the base body and respectively being pivota'ble about vertical axes for supporting the crane during operation thereof. The crane according to the invention is furthermore characterized by an energy supplying unit supported by said carriage below the path of rotation of said crane means for furnishing energy to said crane means for operating the same.

Motor vehicle cranes for small loads are usually so designed that a movable understructure supported by a semi-trailer or forming a component of a motor vehicle carries al platform by means of a turntable While said -platform in addition to the boom carries an operators cabin with all installations required for the crane operation. The stability during the operation of the crane is obtained by supporting arms which are tiltable on the understructure or are movable into and out of the understructure.

A design of the above mentioned type is, however, not satisfactory when motor vehicle cranes are involved which have to move heavy loads, as for instance 150 tons. Inasmuch as the structural height of the crane in condition of transport, i.e. when the boom is dismounted, is limited by the free height of underpasses or bridges, and inasmuch as a considerable portion of the admissible height is taken up `by the rotatable crane portion, i.e. the platform with the operators cabin, thereon, it will be appreciated that a relatively short height remains for the supporting mechanism of the crane carriage. Consequently, also the ends of the supporting arms by means of which the supporting arms are connected to the supporting mechanism of the crane carriage, can have only a limited height. Therefore, the resistance torque of the cross section of the supporting arms is, precisely at those areas at which the supporting forces act with the longest lever arm, insufficient for the bending stresses resulting from heavy crane loads, unless the supporting arms are unusually wide or a g-reat number of supporting arms is provided. The weight of the supporting arms caused thereby is so great that unduly high pressure is exerted upon the vehicle axles when during the transport of the crane the supporting arms are left on the crane carriage as it is generally customary with lighter loads. Thus, it is necessary to disassemble the supporting arms for the transport of the crane and to assemble the supporting arms again when the crane is to be put to work. These manipulations are, in view ofthe considerable weight of the supporting arms, possible only by providing additional hoisting equipment which, of course, represents additional costs and additional labor whereby Mice the economy of the crane operation is considerably reduced.

It is, therefore, an object of the present invention to provide a heavy load motor vehi-cle crane which Will overcome the above mentioned drawbacks.

It is another object of this invention to provide a vehicle crane of the above mentioned general type, which will be so designed that the supporting arms, even though they will permit a considerable crane load with a considerable boom overhang, can remain on the crane carriage during the transportation of the crane so that no auxiliary devices and considerable time for actuating the same have to be used.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawing, in which:

FIG. 1 diagrammatically illustrates a side view of a heavy load motor vehicle crane of a prior art design.

FIG. 2 shows a side view of a heavy load motor vehicle crane according to the present invention.

FIG. 3 represents a rear view of the crane according to FIG. 2 with the supporting arms tilted outwardly.

FIG. 4 is a top view of the crane carriage of the crane shown in FIGS. 2 and 3 with the supporting a-rms tilted outwardly.

A heavy load motor vehicle crane according to the present invention is characterized primarily in that the crane carriage comprises a torsion resistant base body which has that section which carries the hinges for the supporting arms designed so high that it is a multiple of the height of that rotatable crane section which remains when disassembling the boom for transportation of the crane. The crane according to the present invention is furthermore characterized in that the height of the base body is such that the unit for furnishing the energy for the operation of the crane can be mounted in the crane carriage. The torsion resistant base body may have approximately the shape of a cube. Thus, it can be designed as a sheet metal box while the sheet metal plates, in view of the relatively small surfaces, do either not have at all to -be provided with reinforcing means or only to a minor extent. This base body can at any rate be designed torsion resistant so that the forces and moments exerted by the rotatable upper structure during the operation of the crane can be absorbed by the supporting arms pivotally connected to said base body.

Preferably, the torsion resistant base body has connected thereto a portion of the crane carriage which is not put under load by the crane operation and which comprises the unit for furnishing the energy for the crane operation. Involved in this connection is for instance the diesel engine with the generator and the auxiliary devices pertaining thereto when the crane is designed for diesel electric operation. The winch drums with the electric motors pertaining thereto can likewise be mounted on the rotatable platform.

Advantageously, the crane carriage or crane vehicle is so `designed that the height of the crane carriage part connected to the torsion resistant base body decreases in the direction away from the axis of rotation of the crane. The counter weight which extends downwardly from the platform on the base body extends during the rotation of the crane through the thus created space. That portion of the crane carriage which is connected to the base body and is under no load during the crane operation is preferably designed so much narrower than the base body that two of the supporting arms can be folded onto the crane carriage on both sides thereof when the crane is to be moved to another location. This folding operation can be effected in such a way that the supporting arms will not laterally protrude to any material extent.

Referring now to the drawings in detail, the height normally available on streets and highways for the transport of the crane is designated with the letter H. With the prior art design as shown in FIG. 1, the vehicle frame 1 which rests for instance on a semi-trailer 2 has journalled thereon a platform 4 by means of a ball turntable 3. Arranged on said platform 4 is the engine house 5 which, for instance when diesel engine operation is involved, includes a diesel engine 6 and a generator 7. The counter weight on said platform is designated with the reference numeral 8 while the operators cabin is designated with the reference numeral 9. The boom 10 which when the crane is moving from one place to another is entirely or partially disrnounted, is indicated by dot-dash lines. As will be evident from FIG. 1, with the prior art design, more than half of the available height H, after boom 10 has been disrnounted, is taken up by the rotatable part of the crane. Since consequently the vehicle frame 1 can have a limited height only, the supporting arms 11 can only with limited dimensions a in the direction of the height be mounted on the vehicle frame. Therefore, the moment of resistance of the cross section of supporting arms 11 at those ends by which the arms are connected to the vehicle frame 1 will be so low that considerable difficulties are encountered when the high supporting moments occurring during the crane operation are conveyed from arms 11 to the vehicle frame 1. The supporting arms 11 had, therefore, to be made rather wide and heavy which in turn resulted in a correspondingly heavy design of the connecting structures. Furthermore, in order to realize the necessary support for the vehicle frame during the crane operation and to assure stability, more than four supporting arms have to be connected to the vehicle frame 1. In addition thereto, it is to be mentioned that if the height of the vehicle frame 1 is to be fully taken advantage of for connecting the supporting arms 11, the lower edge of said supporting arms will be located lower than the top side of the vehicle wheels so that the supporting arms cannot be tilted over the wheels if it were desired to fold the same toward the vehicle frame for transporting the crane. Instead, when preparing the crane for movement to another place, it was necessary to disassemble the supporting arms 11 from the vehicle frame and to transport said supporting arms on a separate vehicle. Such an oper-ation is necessary already in view of the considerable weight of the supporting arms which, if they were to remain on the vehicle frame, would exert an undue axle pressure.

The design according to the present invention as illustrated in FIGS. 2 and 3 differs fundamentally from the prior art design as illustrated in FIG. 1. Thus, a torsion resistant base body 12 takes up a considerable portion of the height H available during the street transport of the vehicle. This base body 12 is formed by a sheet metal box which has aprpoximately the shape of a cube. The said base body supports a relatively low platform 14 by means of turntable 13 which is adapted to convey pressure as Well as pulling forces. Platform 14 is just high enough to permit mounting of the winch drums 15 for the lifting and pulling-in mechanism together with the electric motors pertaining thereto in the interior of said `drums 15. The rotatable crane portion 14 does, however, not contain the diesel electric unit. The said diesel electric unit is located in a portion 16 of the crane carriage which is attached to the base body 12. This portion 16 has the same height as the base body 12 so that the considerable height of the base body 12 can be employed for receiving the diesel engine 17.

The purpose of the torsion resistant base body 12 consists in conveying the forces and torques occurring in the rotatable crane portion during the crane operation onto the tiltable arms 19 which rest upon the ground. The portion 16 of the crane carriage which is attached to the base body 12 is under no load during the operation of the crane. The said portion 16 will during the transport of the crane establish the connection between the base body 12 and the front portion of the crane carriage. This is effected for instance as shown in FIG. 2 by resting on la semi-trailer 20. At the corners of the torsion resistant base body 12 there are provided hinges 21 for connecting the supporting arms 19 to said base body 12. Inasmuch as for this purpose there is available the considerable height of the base body 12, the arms 19 will at the connecting ends have a correspondingly great height A as is particularly clearly shown in FIG. 3. Therefore, at said connecting ends of arms 19 a correspondingly high moment of resistance can be realized for absorbing the bending moments produced by the supporting forces so that the arms will have a relatively narrow width. Consequently,'the supporting arms 19 can realize the objects without having an undue weight so that also the dimensions of the hinge joints 21 will be in relatively small limits. This design of the supporting arms with the height required by the base body makes it possible that said arms can have a suiciently long length in order to assure the required stability even when the boom has a considerable overhang.

Inasxnuch as due to the above outlined circumstances the weight of the four supporting arms 19 is relatively low, the arms can remain on the vehicle during the transport of the crane without the danger that undue pressure is exerted upon the vehicle axles. The supporting arms can be so arranged that without interference by the vehicle wheels 22 they can be folded onto the supporting frame on the crane carriage. This is also due to the fact that the crane carriage part 16 can be made smaller than the torsion resistant base body 12 because said part 16 is under no load during the operation of the crane.

As will be seen from FIG. 4, the two lateral walls of the crane carriage part 16 are retracted with regard to the side walls of base body 12. Consequently, two of the supporting arms 19 can be folded toward the side walls o-f `the carriage part 16 for the crane transport without said arms protruding laterally with regard to the base body 12. Corresponding remarks also apply to the two other supporting arms 19 which are folded toward the rear.

As will furthermore be seen from FIG. 2, crane carriage part 16 decreases in height toward the front in such a way that its height over the semi-trailer 20 is less than the height `of the base body 12. The thus gained space is taken advantage of so that the counter weight 23 which is mounted on platform 14 and the upper side of which, in view of the height H, is flush with the top side of platform 14, will extend downwardly into the said space when the platform 14 occupies the position shown in FIG. 2.

To the oppositely located end of platform 14 there is connected a foot piece 24 of the boom. This connection is effected by means of a joint bolt 25. After the main portion of the boom has been disrnounted, said foot piece 24 is tilted downwardly in the manner shown in FIG. 2 so that it will not protrude beyond the height H. The operators cabin 26 is for instance arranged :at the front end of .platform 14, and for this purpose the boom foot piece 24 is fork-shaped. It is also possible to arrange the operators cabin on the foot piece 24 if it is not considered Iobjectionable that the said cabin takes part in the relatively small tilting movements ofthe boom. The operators cabin may also be arranged inside the platform 14 if in upward direction there is available sufficient spa-ce to permit the cabin with its windows to protrude beyond the platform.

The space in the torsion resistant base body 12 can be used for receiving mechanical and electrical devices. This space is, for all practical purposes, not narrowed by reinforcing means. Advantageously, the four edges at which the hinges 21 are arranged are stiffened or reinforced by corner bolts.

It is, of course, to be understood that the present invention is, by no means, limited to the particular arrangements shown in the drawings but also comprises any modifications within the scope of the appended claims.

What I claim is:

1. A wheel supported heavy load crane adapted to be pulled by a motor vehicle, which includes: carriage means, a torsion-resistant base body supported by said carriage means, rotatable crane means supported by said base body for rotation about a vertical axis and including platform means and boom means detachably pivotally connected to said platform means, the height of said base body being a multiple of the height of said platform means, supporting leg means movably connected to said base body and respectively movable from an ineffective position to anr effective position for supporting said crane during operation thereof, and an energy supplying unit supported by -said carriage means below the path of rotation of said rotatable crane means for furnishing energy to said crane means for operating the same.

2. A crane according to claim 1, in which said torsionresistant base body has approximately the shape of a cube.

3. A crane according to claim 1, in which said torsionresistant base body has an extension not affected by the load exerted upon `said torsion-resistant base body by said rotatable crane means during the operation of the latter, said extension having mounted thereon said energysupplying unit and Ihaving its free end adapted to rest on -a motor vehicle for pulling said crane.

4. A crane :according to claim 1, in which said energysupplying unit includes a diesel engine-generator unit.

5. A crane according to claim 1, which includes winch means and electric motor means operatively connected thereto, both said winch means and said electric motor means being arranged within said platform means.

6. A crane according to claim 3, in which said extension decreases in height in the direction away from said base body so that the top surface of the free end portion of said extension is considerably lower than the top surface of said base body, said platform means being provided with counter weight means extending downwardly from said platform means in the direction toward but being spaced from the plane of the top surface of the free end portion of said extension to thereby permit free rotation of said platform means with said counter weight means above and beyond said end portion of said extension.

7. A crane according to claim 3, in which said extension has a width narrower than the width of said base body to permit folding of said supporting leg means to the sides of said extension 4so that said folded supporting leg means will not materially protrude laterally from said extension.

8. A crane according to claim 1, in which the pivotal connection of said supporting leg means with said base body is located at a level higher than the top surface of the wheels of said crane to permit turning of said supporting leg means laterally above the top surface of said wheels.

References Cited UNITED STATES PATENTS 882,086 3/l908 Webber 212-145 2,911,111 11/1959 GIOVe 212-35 3,237,781 3/1966 Heigl Ql2-l45 3,249,336 5/1966 Brown 212--35 ANDRES H. NELSEN, Primary Examiner.

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