US3477588A - Crane jib - Google Patents

Description

K. E. REISCHL Nov. 11, 1969 CRANE JIB 7 Sheets-Sheet 1 Filed April 6, 1967 INVENTOR KARL E- REISCHL m%az AT TORNEY K. E. REISCHL Nov. 11, 1969 CRANE JIB 7 Sheets-Sheet 2 Filed April 6, 1967 INVENTOIR KARL E- REISCHL W? ATTORNE K. E. REISCHL Nov. 11, 1969 CRANE JIB 7 Sheets-Sheet 5 Filed April 6, 1967 INVENTOR KARL E- REISCHL ATTORNEY Nov. 11, 1969 K. E. REISCHL 3,477,538

CRANE JIB Filed April 6, 1967 7 Sheets-Sheet 4 INVENTOR KARL E. REISCHL ATTORNEY Nov. 11, 1969 K. E. REISCHL 3,477,588

CRANE JIB Filed April 6, 1967 7 Sheets-Sheet 5 INVENTOR KARL E. REISCH L VAdQZ zz AT TORNEY Nov. 11, 1969 E. REISCHL 3,477,588

; INVENTOR KARL E- REISCHL ATTRNEY United States Patent O US. Cl. 21255 11 Claims ABSTRACT THE DISCLOSURE A ship mounted hydraulic crane having a cantilevered telescoping boom has a jib pivotally suspended from the foot section of the boom. Rods connect the jib to the intermediate boom section for hoisting the jib, and the cable drum for the jib hook is mounted on the jib. In one embodiment, the jib is fastened to the ends of arms suspended from the upper side of the boom. In another embodiment, the jib is suspended from a slidable mounting. In both embodiments, hydraulic cylinders position the jib longitudinally of the boom.

BACKGROUND OF THE INVENTION This invention relates to the superstructure of cranes. The embodiment shown is an hydraulic crane having a telescoping cantilevered boom adapted for mounting on a oceanographic survey vessel for hoisting survey submersibles, launches, buoys and the like to and from the water. However, the impact of the invention extends more broadly to all types of cranes that could employ a jib pivotally suspended from a boom hoisting and controlling loads.

The prior art has employed cranes with jibs pivotally suspended from the booms. In US. Patents Nos. 2,187,- 439 and 2,187,714 teach the use of a crane with a jib suspended from a boom for hoisting and mooring seaplanes to a tender. Also, an hydraulic crane with a cantilevered telescopic boom and having a jib jivotally suspended from a foot section of the boom with rods connecting the jib to the top of the boom for hoisting the jib has been used on an oceanographic survey vessel. An hydraulic cylinder was mounted on the jib of the latter device with a hoist cable connected to its piston rod.

All of the foregoing devices lacked the versatility, flexibility, load handling capacity and load control capabilities of a crane embodying the present invention. These features are becoming increasingly important, not only in cranes used on oceanographic survey vessels, but on all cranes, and particularly on marine cranes, whether ship, land or tower mounted.

SUMMARY OF THE INVENTION The present invention relates to a jib assembly for a crane and more specifically the invention resides in a pivotal suspension apparatus whereby the jib may be moved longitudinally of its supporting boom; also, the invention resides in a pivotal suspension apparatus whereby the jib may swing both substantially parallel to and substantially transversely of the boom; and the invention resides in a jib having its cable drum with hoist cable mounted on it.

As a result, structures embodying the present invention manifest advantages heretofore unavailable with cranes known to the prior art. The radius of the load may be controlled throughout the hoisting of the jib so as to maximize the load capacity of the crane. The load may be precisely, positively controlled on the end of the jib from the point of pick-up to release. The jib may have a very wide range of reaches, and to add further to its versatility, the jib is readily stowed tightly under the boom without dismantling it to allow the boom a full range of use without interference from the jib. The mounting of the cable drum directly on the jib permits broad range, precise speed control of the cable, high. speed cable payout without additional pay-out apparatus and full hoist cable length.

The foregoing and other objects and advantages of the present invention will be revealed in the following detailed description of the embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a ship mounted crane embodying the present invention.

FIG. 2 is a side elevation of the crane shown in FIG. 1 with the boom extended and the jib stowed.

FIG. 3 is a side elevation of a crane shown in FIGS. 1 and 2 with the boom angle raised.

FIG. 4 is a front elevation of the jib shown in FIG. 1 taken along the line 44 in FIG. 5.

FIG. 5 is a side elevation of the jib shown in FIG. 4 taken along the line 5-5 in FIG. 4.

FIG. 6 is a front elevation partially in section of the crane shown in FIG. 1, illustrating the attitude of the jib when the ship is rolling in heavy seas.

FIG. 7 is a rear elevation of a portion of the crane shown in FIGS. 1-3, taken along the line 7-7 in FIG. 1.

FIG. 8 is a side elevation of an alternative embodiment of the jib suspension apparatus for the crane shown in FIGS. l-4

FIG. 9 is a front elevation of the alternative embodiment shown in FIG. 8 taken along the line 99 in FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the embodiment shown in the drawings a crane 1 is mounted on a deck 2 of a ship 3, and the water level is represented by line 4. The crane is mounted on a base 5 that stands on the deck 2 and supports a swing drive mechanism 6, portions of which can be seen in FIGS. l-3 and 7. A revolving frame 7 is rotatably supported on top of the base 5 and has a ring gear 8 mounted beneath it as a part of the swing drive mechanism 6. The revolving frame 7 mounts a crane cab 9 on one side of its front end, a crane drive mechanism 10 behind the cab 9, and a boom 11 which has a foot 12 pivotally supported on a boom pedestal 13 on the other side of the front end of the revolving frame 7 beside the crane cab 9.

The boom 11 is a cantilevered telescoping type of boom that is made up of a foot section 14, an intermediate section 15, which telescopes in the foot section 14, and a top section 16 telescoping in the intermediate section 15 and supporting a pair of hoist sheaves 17 and 18 on its top end. Automatic power driven hose reels 19 are mounted on the very foot end 12 of the boom 11 for hydraulic hose serving components mounted on moving boom sections, and a power driven auxiliary cable drum 20 is mounted on the top of the foot 12 of the boom 11 to control and drive an auxiliary hoist cable 21 that passes over the hoist sheaves 17 and 18 and supporting a conventional hook 22 from the top of the boom 11.

On the top end of the foot section 14 of the boom 11 a bracket 23 projects upwardly for pivotally supporting a swinging arm means made up of a pair of arms 24 suspended from one end along opposite sides of the boom 11, so that the free ends of the arms 24 may swing through a vertical arc beneath and longitudinally of the boom 11. The arms 24 extend below the boom 11, and a jib 25 is pivotally mounted on the bottom, free ends of the arms 24. In this embodiment, the bracket 23, arms 24 and the mounting of the jib 25 make up what will be termed a pivotal suspension apparatus 26 for the jib 25. A pair of jib positioning means made up of a pair of hydraulic cylinders 27 are provided on either side of the boom 11 to control the pivotal positioning of the arms 24 andthusof the top end of the jib 25. The jib position- 'ing cylinders 27 are end mounted hydraulic cylinders, each ,havingfa blind end 28 of its bore 29 pivotally mounted to a lug 30 on the underside of the boom 11 behinfd the arm 24 and a piston rod 31 pivotally fastened to the associated arm 24 intermediate its ends.

A pair of boom hoist cylinders 32 are end mounted between the boom pedestal 13 and the lug 30 on the underside ofthe boom 11 to raise and lower the angle of the boom 11 by pivoting it about the pivotal mounting at the foot end of the foot section 14 of the boom 11. A boom ex- 33 is mounted beneath the boom 11, and it has a rod end 34 of its bore 35 trunnion mounted beneath the top end'of the foot section 14, a piston rod 36 fastened to a bracket 37 beneath the top end of the intermediate section 15, and a blind end 38 resiliently supported beneath the foot end of the foot section 14 of th boom 11. A boom extension cylinder (not shown) for telescoping the top section 16 in theintermediate section 15 is mounted inside the hollow boom 11 in the manner disclosed in the copending application owned by the same assignee as the present application and having the Ser. No. 618,254, filed on Feb; 1, 1967. Jib hoist means consist in part of a pair of jib hoist rods 39 that have their top ends pivotally fastened to the bracket 37 on the top end of the intermediate section 15 of the boom 11, and their bottom ends pivotally fastened to the front of the jib 25 at a point intermediate the ends of the jib 25. Thus the jib 25 will be pivoted about its mounting by the telescoping action of the intermediate boom section 15 in the foot section 14.

The jib 25 mounts a main cable drum 40 for operating a main hoist cable 41, which passes from the main cable drum 40 downward between a pair of guide sheaves 42 and 43 and out oft he lower end of the jib 25. A novel, lightweight hook 44, which is disclosed and claimed in the copending application of the same inventor, owned by the same assignee filed on Apr. 10, 1967, and having the Ser. No. 629,612, is fastened on the end of the main hoist cable 41. The main cable drum 40 is power driven by means of a gear train 45 and several hydraulic motors 46 which are also mounted in the jib 25, in the manner fully described and claimed in a copending application of the same inventor, owned by the same assignee and filed on Apr. 14, 1967, having the Ser. No. 631,083. I A FIGS. 4 and illustrate in greater detail the portion of the pivotal suspension 26 of the jib 25 at the mounting point of the jib 25. An arbor 47 is rotatably supported between the bottom ends of the arms 24 on shafts 48 and 49 that are mounted through bearings 50 in the bottom ends of'the arms 24 and through bearings 51 in the ends of the arbor 47. The jib 25 is pivotally suspended from a shaft 52, which is mounted through the center of the arbor 47 parallel to a longitudinal axis of the boom 11. Thus the jib 25 can pivot about the shaft 52 in a plane transversely of the longitudinal axis of the boom 11, and it can pivot about the shafts 48 and 49 in a plane parallel to the longitudinal axis of the boom 11. To accommodate this motion, the'jib hoist rods 39 have their bottom ends pivotally fastened to opposite ends of a swivel 53, the center of which is pivotally fastened on a shaft 54 through the center of a box frame55. Gudgeons 56 project from the ends of the box frame 55, and are journaled in bearings 57 in the opposite side walls of the jib 25. Thus the jib hoist rods 39 can also pivot relative to the jib 25 in a plane substantially transversely of the longitudinal axis of the jib "25," and in a plane substantially parallel to the longitudinal axis of the jib 25. The top ends of the jib hoist rods 39 are pivotally mounted about pins 58 which are parallel to the boom 11 and journaled through the ends of links 59, and the opposite ends of the links 59 are pivotally mounted about pins 60 which extend transversely of the boom 11 through a bracket 37 on the top end of the intermediate section 15. Hence the top ends of the jib hoist rods 39 can pivot in planes transversely of the longitudinal axis of the boom 11 and parallel to the longitudinal axis of the boom 11. This unique mounting of the jib 25 may be aptly referred to as a gimbal mounting, and it allows the jib 25 to remain vertical as the ship 3 rolls in heavy seas causing the crane 1, and thus the boom 11, to swing through an arc of 40, 20 on either side, vertical as illustrated in FIG. 6. This is important not only for proper load control, but it is critically important to the prevention of excessive torsional loading of the boom 11.

In addition to providing for swinging of the jib 25 in an are substantially transversely of the longitudinal axis of the boom 11, means are also provided for damping pendulation of the jib 25 and its load about the jib suspension axis parallel to the boom 11. The pendulation damping means 61 includes a semi-circular brake segment 62 which is mounted on the arbor 47 to pass through the end of the jib 25 beneath the jib suspension shaft 52. Inside the end of the jib 25, a frame 63 supports a brake shoe 64 which is biased against the brake segment 62 by a pair'of brake springs 65. Thus, while the jib 25 is free tO SWing in a plane transversely of the boom 11, the frictional engagement of the brake shoe 64 on the jib 25 against the brake segment 62 secured to the arbor 47 on the arms 24 is suflicient to dampen any pendulation of the jib 25.

FIG. 7 illustrates the supporting means for the crane 1 of this embodiment of the present invention. The base 5 has a crown 66 bolted to its top, and the crown 66 supports an inner race 67 of a swing circle bearing 68 and laterally protecting shelves 69 and 70, which support the motive power source for the swing drive mechanism 6. From each of the shelves 69 and 70, respectively, a transmission 71 and 72 is suspended, and the transmissions 71 and 72 terminate in pinions 73 and 74, respectively, which are driven by pairs of hydraulic swing motors 75 and 76. Swing drive pinions 77 and 78 are mounted on top of the shelves 69 and 70, respectively, and connected to be driven by the associated gear trains 71 and 72. The swing drive pinions 77 and 78 engage the ring gear 8 which is bolted to the bottom of the revolving frame. The interior rim of the ring gear 8 also forms an outer bearing race 79 for the swing circle bearing 68. The hydraulic motors 75 and 76, which provide swing motive power for the crane 1 are controlled through an appropriate and conventional control system by means of controls inside the crane cab 9. Any number of shelves, such as shelves 69 and 70, may be formed on the crown 66 to support any number of individual swing motive power sources as may be required for the specific crane. It is also possible, and in many instances desirable, to mount the swing motive power sources on the revolving frame 7 to operate on an internal ring gear mounted on the base.

FIGS. 8 and 9 illustrate an alternative embodiment for the pivotal suspension apparatus for the jib 25. According to the alternative embodiment, a box beam 80 is welded to a lower corner of the foot section 14 of the boom 11, and the box beam 80 has wide, longitudinal slots 81 through its opposite lateral walls forming parallel guideways traversed by rollers 82. An axle 83 joining the rollers 82 passes through an eye 84 inside the box beam 80 on the end of a piston rod 85 of a jib positioning cylinder 86, which in this embodiment has both a blind end (not shown) and a rod end 88 of its bore 89 fastened to the underside of the foot section 14 of the boom 11. The ends of the axle 83 project out of the box beam 80 and are journaled through bearings 90 in the tops of forked ends 91 of a jib 92, which in all other respects may be the same as the jib 25 of the other embodiment. Hence, in this alternative embodiment the hydraulic jib positioning cylinder 86 reciprocates the jib 92 linearly in the guideway formed by the slots 81 in the box beam 80 to effect a jib positioning longitudinally of the boom 11 similarly to the jib positioning achieved by the swinging arms 24 in the first embodiment. Although not shown in the alternative embodiment in FIGS. 8 and 9, the pivotal suspension apparatus of the alternative embodiment can, of course, include means for pivoting the jib 92 in a plane transversely of the longitudinal axis of the boom 11 in the same manner as was shown in the first embodiment.

FIGS. 1, 2 and 3 illustrate some of the diflerent operating positions of the boom 11 and the jib 25. In FIG. 1, the top section 16 of the boom 11 is completely retracted within the intermediate section 15, but the intermediate section in solid line is only partially retracted in the foot section 14. The jib positioning cylinder 27, acting simultaneously on both sides of the boom 11, are retracted to the ends of their strokes, to swing the arms 24 and the top of the jib 25 in solid line to their rearmost positions. That combination of conditions places the solid line jib 25 in its shortest reach or operating radius 14 feet in the manufactured model in a vertical position, where there is no compression on the hoist rods 39. (The jib 25 in this position in the manufactured model has a maximum load of 40,000 pounds.) By extending the intermediate section 15, as shown in broken line, with the extension cylinder 33, the jib 25 will be hoisted by the hoist rods 39 fastened to the intermediate section 15, and when the jib positioning cylinders 27 are. extended swing the arms 24 forward, as is shown in broken line, the jib 25 reaches its maximum operating radius. (In the manufactured model the maximum operating radius exceeds 33 feet, where the maximum load is 10,000 pounds.)

Turning now to FIG. 2 where the intermediate boom section 15 is held in the same position as shown in solid line in FIG. 1 and the jib positioning cylinders 27 are fully extended to push the arms 24 to their forwardrnost position, the solid line jib 25 is pushed up to an almost horizontal attitude immediately beneath the foot section 14 of the boom 11. Thus the solid line jib 25 in FIG. 2 is in its stowed position, where it may be tied or hooked by some simple mechanical latch to hold it out of the way while the auxiliary hook 22 off the top end of the boom 11 is in use. The jib 25 in broken line in FIG. 2 is in an intermediate attitude between its vertical position and its stowed position, which is achieved by only partially extending the positioning cylinder 27. Both the stowed position and the intermediate position shown in FIG. 2 place the hoist rods 39 in compression, which they are not designed to sustain under heavy loading, and hence care must be taken in operating this embodiment not to load the jib excessively when it is in these positions.

Comparing the positions of the boom sections 15 and 16, as shown in solid and broken line in FIG. 1, and as shown in FIG. 2, shows an uncommon type of operation. Usually, in such crane booms, a distributor of one sort or another is inserted in the hydraulic circuitry to ensure automatic, uniform extension and retraction of the telescoping boom sections. However, in this embodiment, the intermediate section 15 and the top section 16 may be extended and retracted independently of one another. This is desirable so that the reach of the boom 11 may be, in part at least, independent of the hoist of the jib 25.

In FIG. 3, the angle of the boom 11 is raised, the jib 25 is held in its vertical attitude, but a careful comparison of FIGS. 1 and 3 will show that the operating radius is the same in both. It would be expected that as the angle of the boom 11 increases, raising the jib 25, the operating radius, or reach, of the jib 25 would decrease, as it surely would, if the jib positioning cylinders 27 were held in the fully retracted position shown in FIG. 1. However, by partially extending the jib positioning cylinders 27, as shown in FIG. 3, the arms 24 are swung outwardly carrying the jib 25 with them. Thus the same operating radius is maintained and a vertical hoist is achieved. This feature gains further importance in the situation where a maximum load is lifted from the deck 2 to be lowered into the water. That operation would require a lowering of the boom angle and normally a concomitant increase in reach, which would cause an overload. However, the present invention allows the operator to pull in the jib 25, using the jib positioning cylinders 27 operating on the arms 24, to maintain a constant reach and thus to prevent an overload. As a corollary, the load handling capacity of the crane is maximized.

FIGS. 4, 5 and 6 highlight another aspect of the present invention. FIG. 6 illustrates the eifect of the rolling of the ship 3 on the crane 1, the boom 11 and the jib 25. As the ship 3 rolls, the crane 1 swings with it, and the boom 11 tends to rotate, more or less, about its longitudinal axis. Nevertheless, the jib 25 remains vertical. If the jib 25 were fixed to swing with the rotation of the boom 11, severe and even destructive torsional forces would be exerted on the boom 11 and the jib mounting by a load on the end of the jib 25. However, the present invention provides a unique gimbal mounting for the jib 25 in the pivotal suspension apparatus 26, so that the jib 25 can swing both substantially parallel to and substantially transversely of the longitudinal axis of the boom 11. This feature not only releases torsional forces that could otherwise destroy the jib mounting or the boom 11, but it also permits more precise control of a load on the jib 25. Pendulation of the jib 25 and its load in a plane parallel to the boom 11 is prevented by the hoist rods 39, but pendulation transversely of the boom 11 would be unchecked in the absence of the unique damping means 61 of the present invention. The pendulation damping means 61 employs a braking surface 62 in the shape of a circle segment anchored to the boom 11 in the transverse swing plane of the jib 25 and a brake shoe 64 on the jib 25 and spring biased against the brake lining 62 to slide along the brake lining 62 as the jib 25 swings. This damping means 61 allows the jib 25 to swing under load, but it effectively and rapidly clamps any pendulation that might tend to result.

Since the crane 1 must be able to swing even when the ship 3 is heeling as much as 20 from the horizontal, special provision in the swing mechanism 6 is required. In the embodiment shown here, the swing drive pinions 77 and 78 are supported by base 5 to drive an external swing ring gear 8 to provide the necessary swing torque. Also, the weight limitations imposed on a crane for a small vessel may prohibit use of a counterweight, so in the embodiment shown, the revolving frame 7 is lengthened rearwardly and the crane drive mechanism 10 is mounted on the back end of the revolving frame 7.

FIGS. 8 and 9 show an alternative jib suspension apparatus wherein the top 91 of the jib 92 is suspended from the rollers 82 captive in the longitudinal slots 81 of the box beam that is mounted on the boom 11. Thus the jib positioned cylinder 86 can reciprocate the top 91 of the jib 92 in rectilinear movements, instead of the swinging movement employed in the first embodiment. The operation of the jib 92 would be substantially the same as the already described operation of the jib 25 of the first embodiment. However, the gimbal mounting of the jib suspension apparatus 26 of the first embodiment is omitted in the alternative embodiment to illustrate a crane jib embodying the present invention where the swinging movement transversely of the boom 11 is not required. Alternatively, a crane jib embodying the present invention might employ the gimbal mounting of the first embodiment but omit the jib positioning feature shown in both embodiments.

The jib hoist means in the form of the hoist rods 39 and associated connections to the boom 11 and the jib 25 are particularly suited to the needs of the specific embodiment shown, but other forms of jib hoist means might serve better in other applications. For example, a hoist cable :might have its ends fastened to the side of the boom 11 similarly to the hoist rods 39 and the cable might pass around a pulley mounted on the shaft 54 in place of the swivel 53. A single hoist cable might be used, or the hook 22 on the auxiliary cable 21 might engage in eye on the jib 25 so that the jib 25 could be hoisted by either extending the top section 16 of the boom or winding in the auxiliary cable with its cable drum 20. Or one, or more hydraulic cylinders could be connected between the jib 25 and the boom 11, directly or indirectly, for hoisting the jib 25. Also, the jib positioning function could be accomplished by connecting the arms 24 (or the roller 82 in the second embodiment) to the intermediate or top boom sections and 16 and extending and retracing the boom 11, and this would obviate the need for the jib positioning cylinder 27 (or 86).

The foregoing discussion does not, by any means, exhaust the possible alternative embodiments, nor is it intended to do so. From the description of those em bodiments those skilled in the art may learn to practice this invention in its manifold forms employing the numerous equivalent expedients known to the art where the application demands it.

' I claim:

1. A jib assembly for a crane comprising the combination of a jib suspension apparatus for mounting intermediate opposite ends of a boom and having a pivotal jib support allowing pivotal movement substantially parallel to a longitudinal axis of said boom and pivotal movement substantially transversely of said longitudinal axis of said boom;

a jib having its top end suspended from said pivotal jib support to swing substantially parallel to and transversely of said boom;

and means connecting said jib to said boom for swinging said jib substantially parallel to said boom.

2. A jib assembly as set forth in claim 1 wherein said jib suspension apparatus includes an arbor supported on said boom to rotate about an axis substantially transversely of said boom, and a shaft mounted perpendicularly to said arbor on said boom;

and said jib having its top end pivotally suspended from said shaft to pivot about said shaft in a plane substantially transversely of said boom.

3. A jib asembly as set forth in claim 1 wherein said means connecting said jib to said boom includes a rod having one end pivotally fastened to rotate transversely of said jib to a frame mounted on said jib to rotate about an axis substantially transversely of said jib, and said rod having an opposite end pivotally fastened to one end of a link means to pivot transversely of said boom, an opposite end of said link means being pivotally fastened to said boom to pivot substantially parallel to said boom.

4. A jib assembly as set forth in claim 2 wherein said jib suspension apparatus includes a pendulation damping means to damp jib pendulation substantialiy transversely of said boom.

5. A jib assembly set forth in claim 4 wherein said pendulation damping means includes a brake surface shaped in a segment of a circle and mounted on said arbor transversely of said boom, and a brake shoe mounted on said jib and spring biased into engagement with said brake surface.

6. A crane boom with a jib. the boom having a foot end and a top end with said foot end being pivotally mounted on a revolving frame rotatably mounted on a base so that said top end of said boom can be raise or lowered by pivoting said boom about the pivotally mounted foot end and said boom can be swung in a horizontal are by rotating said revolving frame, in combination therewith swinging arms pivotally mounted one one end to said boom at a position intermediate said foot end and said top end of said boom, said swinging arms being elongated members having swinging ends suspended beneath said boom to swing about said pivotal mounting;

a depending jib having an inner and an outer end, said inner end being pivotally fastened to said swinging ends of said swinging arms to pivotally support said depending jib therefrom, and said outer end having hoist cable support means mounted in it;

power means connected to said boom and said swinging arms to swing said arms about said pivotal mounting on said boom to thereby move said depending jib in and out longitudinally of said boom;

hoist means acting between said top end of said boom and said jib for pivoting said jio about its pivotally mounted end on said swinging ends of said swinging arms;

and a hoist cable suspended from said hoist cable support means on said outer end of said jib to move a load toward and away from said outer end of said jib.

7. A crane boom and jib as set forth in claim 6 wherein said boom has a power driven auxiliary cable drum with an auxiliary hoist cable fastened to it and passing over sheave means at said top end of said boom.

8. A crane boom and jib as set forth in claim 6 wherein said boom has a plurality of sections mounted in telescoping relationship.

9. A crane boom and jib as set forth in claim 8 wherein said jib hoist means includes a rod end mounted between said top of said boom and said jib.

10. A crane boom and jib as set forth in claim 9 wherein said boom is cantilevered and has hydraulic cylinders as said boom hoist means and hydraulic cylinders to extend and retract said plurality of sections mounted in telescoping relationship.

11. A crane boom and jib as set forth in claim 10 wherein said swinging arm means includes a pair of arms mounted on opposite sides of said boom and suspended from a pivotal mounting above said boom.

References (Iited UNITED STATES PATENTS 2,187,714 1/1940 Woodeson 212-3 3,348,702 10/1967 Wennerstrom 21254 3,295,705 1/1967 Peterson 212-55 3,367,514 2/1968 Marklund 21235 3,055,511 9/1962 Sharp 212--8 3,401,804 9/1968 Link 2123 FOREIGN PATENTS 1,421,012 11/1965 France.

HARVEY C. HORNSBY, Primary Examiner US. Cl. X.R. 212-58, 69, 144

533 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N 3, Dated March Inventor(s) Karl ROiSChl It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 29, change "a" to an- Column 1, line 40, change "jivotally" to ----pivotally-'-- Column 3, line 13, after "foot" insert --12--, delete "end of the foot section 14-- Column 3, line 13, strike "A" and insert --One--, delete "ex" and insert -telescoping cylinder-- Column 3, line 36, change "oft" to --ofand he" to --the-- Column 6, line 52, change "positioned" to "positioning- Column 7, line 10, change "retracing" to --retracting-- Claim 3, Column 7, line 43, change "ascmbly to ---assembly-- Claim 5, Column 7, line 5'2, after "assembly" insert --as-- Claim 6, Column 7, line 63, the period after "jib" should be a comma Claim 6, Column 8, line 6, change "one" (first occurrence) to --on-- SIGNED AND SEALED JUL 2 8 I970 SEAL WILLIAM E. sasumm, m. Edward M. Fl h 3 inston of Pawn Attesting Officer

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