US3204795A

US3204795A - Log loading apparatus

Info

Publication number: US3204795A
Application number: US287136A
Authority: US
Inventors: Robert W Larson
Original assignee: Beloit Corp
Current assignee: US TRUCK CRANES Inc A PA CORP; Beloit Corp
Priority date: 1963-06-11
Filing date: 1963-06-11
Publication date: 1965-09-07
Anticipated expiration: 1982-09-07

Description

Sept- 7, 1965 R. w. LARSON 8,2o4,795

I LOG LOADING APPARATUS Filed June ll, 1965 4 Sheets-Sheet 1 INVENTOR. ROBERT M 'msa/v Aria/M1875 Sept. 7, 1965 R. w. LARsoN LOG LOADING APPARATUS 4 Sheets-Sheet 2 Filed June ll, 1963 1NVENT0R Ro 8:27 hl. ldsaw mNlrnNl /m Arraavzrs Sept- 7, 1965 R. w. LARSQN 8,204,795

LOG LOADING APPARATUS Filed June ll, 1963 4 Sheets-Sheet 4 a W INVENTOR.

ywi/www United States Patent O l3,204,795 LOG LOADING APPARATUS Robert W. Larson, "Ashland, Wis., assgnor to Beloit Corporation, `Beloit, Wis., a corporation of Wisconsin Filed June '11, '1963, Ser. No. 287,136 13 Claims. (Cl. 214-`147) This invention relates generally to loading or handling apparatus, and pertains more particularly to apparatus of this character in which a boom assembly is rotatable about a generally Vertical axis and has a grapple suspended from the free end thereof.

A general object of the invention is to decrease substantially the time required to transfer articles requiring orientation, such as tree length logs, from one place to another. By way of example, the invention envisages the lifting of logs from a pile of such logs on the ground, even though the pile is at any arbitrary angle, and loading the logs onto a nearby truck, or presenting such logs in a properly oriented manner to a slasher which is customarily employed in the logging art for cutting the tree length logs into shorter lengths called sticks. For convenience, the transferring of a load comprising an individual article is considered heren, though it is understood that a plurality of logs or other articles such as pipes may also be handled.

More specifically, the invention has for an object the indexing of the grapple into a preferred angular position with respect to the boom assembly, which preferred angular position results in the grapple being properly aligned with the logs to be picked up. It is within the contemplation of the invention to preset the grapple into this predetermined angular position and have the grapple automatically returned or indexed back to such position each time a log is to be picked up from a given pile.

Another object of the invention is to provide for the automatic freeing or disengagement of the indexing means by the weight of the log, such freeing action permitting the grapple to be moved into a different angular position with respect to the boom assembly that is more suitable for loading purposes, such as being in direct alignment with the longitudinal axis of the boom assembly.

Yet another object of the invention is to provide for the leveling of the log once it has been picked up or lifted from the pile, the indexing means in no way interfering with the means for leveling the log.

Quite briefly, the invention includes an articulated boom assembly swingable about a generally Vertical axis and which boom assembly can be also swung upwardly and downwardly. At the free end of the boom assembly is suspended a grapple which is capable of being swiveled about a transverse axis and about an axis perpendicular to said transverse axis. An adjustable cam arrangement is utilized for indexing purposes, which after being once set, always assures that the grapple will be properly oriented for picking up successive loads of logs or groups of logs from a given pile, The cam arrangement becomes automatically disengaged once a load has been picked up due to the weight of such load. However, when the load that has been picked up has been transferred and released, then the grapple automatically returns by spring action to the preset position in preparation for picking up the next load.

These and other objects and advantages of my invention will more fully appear from the following description, made in connection With the accompanying drawings, wherein like reference characters refer to the same or similar parts throughout the several views and in' which:

FIGURE 1 is a top plan view of my loading apparatus shown in the immediate vicinity of two piles of logs that are to be loaded onto a nearby truck;

FIGURE 2 is a side elevational view corresponding to FIGURE 1, the view being on a somewhat larger scale and also showing the loading apparatus in two phantom outline positions;

FIGURE 3 is a top plan view illustrating the free end of the boom assembly and the parts carried thereby;

FIGURE 4 is a side elevational view corresponding to FIGURE 3;

FIGURE 5 is a view, partly in section, taken generally from the left in FIGURE 4 along the line 5 5, and

FIGURE 6 is a sectional view taken generally in the direction of line 6-6 of FIGURE 5.

Referring now in detail to the drawings, a rotary main boom assembly designated in its entirety by the reference numeral 10 |has been pictured, this boom assembly being mounted on a truck 12 through the agency of a capstan 14. In the illustrated instance, the boom assembly 10 includes articulative boom members labeled 16 and 18. Boom member 16 is pivotally connected to the capstan 14 'by a transverse pivot pin 20, whereas the end boom member 18 is pivotally connected to the boom member 16 by I means of a second transverse pivot pin 22. Thus, the

boom assembly 10 is designed to be swung or rotated about a Vertical axis, and the boom member 16 is adapted to be raised and lowered by a hydraulic ram 24, whereas the end boom member 18 is pivotally movable with respect to the boom member 16 by reason of a second hydraulic ram 26. T-hese hydraulic rams, as others to 'be referred to hereinafter, are of conventional construction, each including a cylinder and piston. Solely for the sake of simplifying the drawing as much as possible, the hydraulic lines for supplying fluid under pressure to the various hydraulic rams, both those that have -been -mentioned and those that will soon be referred to, have been omitted. Likewise, the lines used for eifecting rotation of the capstan 14 have been omitted.

At this t-ime, attention is directed to the employment of a heel boom structure 28 comprised of a pair of generally parallel side members or strips 30. The heel boom structure 28 is supported at the free end of the boom assembly 10 through the agency of a transverse pivot pin 32 extending through the heel boom structure 28 and the end boom member 18. The pivot pin 32, it will be noted, is located intermediate the ends of the heel boom structure 28. Aft of the pivot pin 32 are laterally spaced clevises 34, these clev'ises 34 -being located on the heel boom structure 28 at either side thereof. Each clevis 34 has a pin 36 extending therethrough and also through a cylindrical mem-ber 38 fixedly carried at the projecting end of a piston rod 40. Consequently, there are two piston rods 40 that are associated with the two hydraulic rams 42 that have been depicted and which are best seen in FIGURE 3. The closed end of each hydraulic ram 42 is equipped with an ear 44 through which a transverse pin 46 extends. In this way, the hydraulic rams 42 are responsible for urging the |heel boom structure 28 arcuately about pivot pin 32 as viewed in FIGURES 2 and' 4 in order to achieve a leveling action hereinafter described.

A swivel mechanism has been denoted generally by the reference numeral 50. Included in the over-all construction of the swivel mechan'ism 50 is a sleeve bearing 52 having oppositely projecting pins 54 fixedly disposed thereon, the pins 54 being received in apertures at the left ends of the strips 30 comprising the heel boom structure 28.

In this Way, the swivel mechanism 50 is pivotal about a transverse axis provided by the oppositely directed pins 54.

As can best `be understood from FIGURES 5 and 6, a Vertical cylindrical column or shaft 56 is reciprocally mounted in the sleeve bearing 52. The column or shaft 56 has at its upper end a head plate or flange 58 that provides an enlargement which 'bears against the upper end of a coil spring 60. Hence, the coil spring 60 reacts against the sleeve bearing 52 to normally urge the column or shaft 56 upwardly. However, the biasing action of the spring 60 is overcome in a manner that will become more apparent as the description progresses.

The swivel mechanism 50 also includes in the illustrated situation a Vframe that has been generally designated by the reference numeral 62. It will be observed from FIGURE 6 that the frame has as a part thereof a base plate or bottom platform labeled 64 provided with an aperture 66 therein. The lower end of the column or shaft 56 extends through the aperture 66 and the shaft has a thrust bearing 68 held in place by a retaining nut 70. By reason of this mode of attachment, the frame 62 can be rotated about the longitudinal axis of the shaft 56, the thrust bearing 68 permitting this.

Loosely encircling the shaft 56 is a sleeve 72 having a pinion 74 integral therewith near its lower end. In mesh with the pinion 74 is a gear rack 76. The gear rack 76 is disposed for reciprocable movement and is actuated |by a pair of

rams

78, 80. Each

ram

78, 80 includes a piston rod 82 directly connected to the ends of the gear rack 76, a piston 84 .and a cylinder 86. The cylinders 86 are formed With flanges at 88 and bolts 90 permit the cylinders 86 to be secured to Vertical plates 92 constituting a portion of the frame 62. Also contributing to the support of the cylinders 86 belonging to the

rams

78, 80 are underlying brackets 94 which can be attached to the Vertical plates 92, as by Welding.

It will be further noted that the frame 62 includes an upper plate or platform 96 and that there .are angularly directed gussets 98 that maintain a sleeve bearing 100 in an encircling relationship with the preViously-mentioned sleeve 72. It will be recalled 'that it was stated that the frame 62 can be rotated aboutthe column or shaft 56 and the sleeve bearing 100 functions as a guide in permitting this, doing so in combination With the thrust bearing 68 that has previously been alluded to. Stated somewhat differently, the sleeve bearing 100 is made integral With the frame 62 by Virtue of -the angularly directed gussets 98 which have their Vertical edges welded t-o the sleeve bearing 100 and their lower edges to the upper plate or platform 96.

The sleeve bearing 100 is formed with a collar 102 at its upper end, the collar functioning as one part of a two-part drum cam and having therein a cam notch 104 for an indexing purpose presently to be made manifest. Engageable in the cam notch 104 is a cam lobe 106 integral with the preViously-mentioned sleeve bearing and constituting the second part of the two-part cam.

The swivel mechanism 50 supports .a grapple unit 108 comprising cooperable sets of

jaws

110 and 112 which are pivoted at their upper ends by pins 114 between the Vertical plates 92 on the frame 62. For the purpose of actuating the

jaws

110, 112 into open and closed positions with respect to each other are rams 116 having their closed ends pivotally connected to clevises 118 through the .agency of pins'120. The rams 116 have projecting piston rods 122 which by means of clevises 124 on the

jaws

110, 112 lare pivotally connected to the jaws by pns 126.

Whereas the swivel mechanism 50 and the grapple unit 108 are suspended from one end of the heel boom structure 28, the heel boom structure 28 carries at its other end a downwardly facing cradle unit 128 composed of rods or

tubes

130, 132 which are bowed upwardly between their ends .and welded to the strips 30. comprising the structure 28. The ends of the rods or

tubes

130, 132 are joned by connecting struts 134 and downwardly directed side strips 136 complete the construction of the cradle unit 128.

Having presented the foregoing description, the manner in which my invention operates will now be presented. To assist in the operational presentation, it will be helpful to refer to two piles of

logs

138, 140 each composed of a plurality of individual logs 142. As can be discerned from FIGURE 1, the pile 138 is generally parallel to the truck 12 carrying the boom assembly 10 and the pile 140 is at appr-oximately a 45 degree angle with respect to the truck. It will be vfurther assumed that the logs 142 contained in the

piles

134, 140 are to be transferred from their ground location to a trailer truck 144 that is to haul the logs away.

In order to effect the loading of the logs 142 onto the truck 144, and assuming that the logs 142 in the pile 138 are to be lifted first, the operator of the truck mounted boom assembly 10 will cause the boom assembly 10 to be swung about the Vertical axis provided by the capstan 14 to the first phantoml outline position shown in FIGURE 1.

The grapple unit 108 may be in any angular position with respect to the general axis of the boom assembly 10 when the boom assembly reaches the first phantom Outline position of FIGURE 1. However, with the grapple unit 108 .above the pile 138, the operator utilizes the rams 78, to reciprocate the gear rack 76 by admitting fluid under pressure to the appropriate ram. Because the coil spring 60 has biased the column or shaft 56 upwardly, there will have been elfected an automatic engagement of the cam notch 104 with the cam lobe 106. Hence, when the gear rack 76 is reciprocated, the presence of the cam lobe 106 in the notch 104 will resist any turning or rotation of the sleeve bearingi relative to the sleeve bearing 52. Consequently, the frame 62 is rotated relative to the sleeve bearing 100 when the gear rack 76 is reciprocated, `since the pinion 74 is retr'ained from rotation under these assumed conditions. Of course, rotation of the frame 62 results in the grapple unit 108 being turned therewith. Thus, it is an easy task to align and thereby preset the grapple unit 108 so that its

jaws

110, 112 are in za position to pick up the first log 142 from the pile 138.

To pick up the first log 142 from the pile 138, the operator will normally utilize the ram 24 to lower the boom assembly 10 to the lower phantom outline position illustrated in FIGURE 2, although the ram 26 can assist in this particular accomplishment if need be. When the boom .assembly 10 has been lowered so that the

open jaws

110, 112 of the grapple unit 108 embrace the first log 142, the operator then activates the hydraulic rams 116 so as to close the

jaws

110, 112 about the 'log 142.

As the boom assembly 10 is raised, the weight of the log Will immediately cause the grapple unit 108 and the frame 62 to be moved downwardly with respect to the column or shaft 56. In other word-s, the coil spring 60 which normally biases the column or shaft 56 upwardly is compressed by the weight of the log 142. Compression of the spring 60 and the concomitant relative down- Ward movement of the frame 62 automatically results in a disengagement of the notch 104 from the lobe 106. This condition is clearly shown in FIGURES 5 and 6. With the notch 104 -lowered so that the lobe 106 is no longer received therein, it will be appreciated that the entire frame 62 is free to be rotated about the column or shaft 56; In this regard, the gear rack 76 has already been indexed so as to rotate the frame 62 into a particular angular position with respect to the pinion 74. Thus, when the entire frame 62 is lowered on the column or shaft 56, the sleeve bearing 72, which loosely encircles the column or shaft 56, will be permitted to rotate freely relative to said column or shaft 56.

The manner in which the rotation relative to the column or shaft 56 is achieved is by swinging the boom assembly about the Vertical axis proivded by the capstan 14 so that the boom assembly is in substantial alignment with the longitudinal axis of the particular log 142 that has been picked up by the grapple unit 108. Owing to the fact that the log 142 will be initially picked up or raised nearer one end than the other, it follows that the far end remains on the pile 138 and the swinging of the boom assembly 10 before raising the entire log causes the end that is still resting on the pile 138 to serve as a pivot point for achieving a general alignment of the log with respect to the boom assembly.

Even though the alignment between the log 142 and boom assembly 10 mentioned immediately above has been obtained, the heavier end of the log, that is, the end thereof more remote from the grapple 108 will still be resting on the pile 138 or on the ground, as the case may be. This gives the operator two choices. First, he can immediately bring the rams 42 for the heel boom structure 28 into action which force the cradle 128 downwardly against the elevated end portion of the log 142, thereby raising the heavier end of the log 142 to clear the pile 138 sufiiciently to permit the boom assembly 10 to be swung about the Vertical axis provided by the capstan 14. Usually, though, the boom assembly 10 will be raised through the operation of the ram 24 so that no part of the grappled log 142 will be touching the pile 138. Then the rams 42 will be activated or operated to cause the cradle 128 to be forced downwa-rdly to level the log as shown in FIGURE 2. In both instances, the heel boom structure 28 is caused to pivot in a clockwise direction as viewed in FIGURE 4 about the pivot pin 32. The pins 54, of course, permit the swivel unit 50 to pivot into or assume whatever angular relationship is necessary to effect the leveling of the log 104.

With the log 142 both level and in alignment with the longitudinal aXis of the boom assembly 10, the boom assembly 10 can be swung about its Vertical axis until the log 142 is over the trailer truck 144. When this angular relationship has been realized, then the boom assembly 10 can be lowered through the agency of the ram 24 and also the ram 26. When the log 142 has been placed or deposited on the trailer truck 144 then rams 116 of the grapple unit 108 are actuated so as to open the

jaws

110, 112 and thereby release the log 142.

The release of the log 142 permits the spring 60 to again raise the column or shaft 56 and such action will move the frame 62 upwardly with the consequence that the lobe 106 is brought into re-engagement with the notch 104. Due to the sloping edges of the notch 104 and the lobe 106, there is a camming of the collar 102 in a direction so as to cause the swivel mechanism and the suspended grapple unit 108 to assume the same angular positions they assumed when they were first brought over the pile 138. It will be appreciated that the grapple unit 108 is relatively light in weight and the desired rotative alignment is easily re-established.

It is important to recognize that the re-orienting of the grapple unit 108, as above outlined, is accomplished without causing the gear rack 76 to reciprocate and act against the pinion 74. Thus, the initial reciprocation of the gear rack 76 causes a presetting of the grapple unit 108 in a desired rotative position that is suitable for picking up the logs 142 from the pile 138 and the grapple will always be automatically returned or indexed back to this rotative position. Thus, when the boom assembly has been swung back to the same angular position over the pile 138 in which the presetting was done, the grapple unit 108 will be properly oriented for the next log to be picked up from this particular pile.

When the logs 142 from the pile 140 are to be loaded, then naturally a re-adjustment is needed since a presetting of the grapple unit 108 for the pile 138 will no longer be suitable. This is easily done, however, by merely reciprocating the gear rack 76 so that it turns the grapple unit 108 into a more pronounced angular position, such posi- 1 s tion resulting in the proper alignment of the

jaws

110, 112 for the axial direction in which the logs 142 of the pile extend.

After resetting the grapple unit 108 so that it is suitable for the pile 140, the same steps are repeated. Namely, the operator lowers the boom assembly 10 so that the log 142 from the pile 140 can be picked up. With one end still resting on the pile 140, the boom assembly 10 can be swung so as to effect a general axial alignment of the log 142 with the longitudinal axis of the boom assembly 10. Then, the boom assembly 10 can be raised sufficiently so as to completely elevate the log and then deposit it on the trailer truck 144 by swinging the boom assembly about its Vertical axis provided by the capstan 14.

While the foregoing operational description is believed to be clearly understandable and straightforward, a special explanation should be given With respect to the relative positions of the indexing means depicted in the various views. The indexing means includes the collar 102 with its notch 104 and the lobe 106 on the sleeve 52, as well as the pinion 74 and rack 76. Because of the various angles through which these parts are moved, it would not be logical to show them in any other angular positions than those pictured in FIGURES 4-6. FIGURE 4 is representative of the swivel mechanism 50 with no log being picked up by the grapple unit 108.

Assuming that logs 142 from the pile 138 are to be picked up, the grapple unit 108 Would in practice have been indexed into an angular position, but this would have resulted in a twisted view of the unit 108 in FIG- URE 4 (and also FIGURE 3), a view indeed difiicult to present. As far as the indexing action is concerned, though, the lobe 106 merely prevents the collar 102 from rotating because in this situation the lobe 106 is engaged in the notch 104, thereby resulting in only the rotation of the grapple unit 108 when the rack 76 is reciprocated because the pinion 74 is under these crcumstances held fast by the lobe 106 and notch 104.

As for FIGURES 5 and 6, it will be perceived that in this situation the weight of a log 142 has caused the collar 102 to be moved downwardly so that the lobe 106 is no longer engaged in the notch 102, thereby permitting the swivel mechanism 50 and the grapple unit 108 to assume any desired angular position, including that shown. The illustrated position shown in FIGURES 5 and 6, quite obviously, corresponds to the solid line position of the boom assembly 10 presented in FIGURE 1, that is, just before the log 142 is released for deposit onto the truck 144.

When the log 142 is released, then the coil spring 60, which has been compressed by the weight of the log, expands, and in doing so causes the sloping edge of the notch 104 profiled in FIGURE 6 to ride upwardly against the right edge of the lobe 106 with the consequence that the collar 102 is rotated relative to the column or shaft 56. The pinion 74 fixedly carried at the lower end of the sleeve 72, which is integral with the collar 102, reacts with the rack 76 to rotate the frame 62 and the grapple unit 108. When the lobe 106 has become fully seated in the notch 106, the grapple unit 108 will have been automatically indexed back to its preset position. This is the position illustrated in FIGURE 4 but with the grapple unit 108 actually swiveled or twisted into an angular position corresponding to that shown in the first phantom outline position of FIGURE 1, this being the preset position for the pile 138.

It will, of course, be understood that various changes may be made in the form, details, arrangements and proportions of the parts without departing from the scope of my invention as set forth in the appended claims.

What is claimed is: 21. 'Loading apparatus for article-s requiring orientation which comprisesz' (a) 'a boom assembly swingable about a generally vertical axis;

(b) load engaging means;

(c) means suspending said load engaging means from the free end of said :boom assembly for rotation relative thereto;

(d) means urging said load engaging means 1nto one angular position with respect to the longitudinal axls of said boom assembly when uninfluenced by the Weight of a load, and

(e) means for 'rendering said urging means ineifectual when said load engaging means is infiuenced by the weight of a load so that said engaging means can be rotated to a different .angular position.

2. Loading apparatus in vaccordance wit'h claim 1 in which: I

(a) said one angular position is out of alignment with said boom assem'bly and said different angular posltion is in substantial alignment with said boom assembly.

3. Loading Aapparatus in aocordance with clam 2 m- (a) means for leveling 'said load when said engaglng means' is in said different angular position.

4. Loading apparatus in acc-ordance with claim 3 in which said leveling means includes;

(a) a heel boom structure pivotally connected intermediate its ends to said free end of said boom assembly, -and ('b) a cradle attached to the end of said heel boom structure nearer said vertical -axis engageable with a laterally extending end portion of the load held by said engaging means,

(c) said engaging means being suspended for swivel movement from the other end of said heel boom structure.

5. Loading apparatus for articles requiring orlentation which comprises:

(a) a boom;

('b) means .mounting one end of said` boom for rotation about a generally Vertical axis;

(c) means suspended ladjacent the other end of said 'boom providing .a bearing structure;

(d) a shaft member extending downwardly thrrough said bearing structure;

(e) grapple means carried by said shaft at the lower end thereof for engaging a load to be -picked up;

(f) spring means normally urging said shaft member upwardly in said bearing structure, and

(g) means including a first cam element fixedly associated With said bearing structure and a second cam element fixedly associated with said grapple means,

(h) said cam elements having a profile such as t-o cause said grapple means to automatically assume a desired angular relations'hip with said boom when said shaft is urged upwardly by said spring means to cause pres- 'sural engagement of said cam elements;

(i) whereby the action of said spring means will be overcome when said grapple means is lifting a load and the weight of such load causing separation of said cam elements to permit rotation of said grapple means.

6. Loading apparatus for articles requiring orentation which comprises:

(a) a boom yassembly swingable about a generally vertical axis;

(b) a first sleeve member carried at the free end of said boom assem'bly with its longitudinal aXis generally Vertical;

(-c) a shaft reciprocably disposed in said first sleeve i member;

(d) a second sleeve member encircling said shaft;

(e) grapple means rotatably supported at the lower end of said shaft;

(f) spring means normally biasing said shaft and second sleeve member upwardly, and

(g) interengaging cam means on said two sleeve members for urging said second sleeve member into a particular angular relation With said first sleeve member when said second sleeve member is biased upwardly.

7. Loading apparatus for articles requiring orientation which comprises:

(a) .a boom assembly swingable about a generally ver- -tical ax'is;

(b) a first sleeve member carried at the free end of said boom assembly With its longitudinal axis gen- 10 eral'ly Vertical;

(c) a shaft reciprocably disposed in said first sleeve member; (d) a second sleeve member encircling said shaft; (e) grapple means rotatably supported at the lower end of said shaft;

(f) spring means normally biasing said shaft and second sleeve member upwardly; (g) interengaging cam means on said two sleeve members for urging said second sleeve member into a particular angular relation with said first sleeve member when said second sleeve member is biased upwardly; (h) a third sleeve member encircling said shaft, (i) said grapple means being rotatable with said third sleeve member, and

(j) means for rotatably positioning said third sleeve member relative to said second sleeve member.

8. Loading apparatus in accordance with claim 7 in which said last-mentioned means includes:

(a) a pinion gear on said second sleeve member, and

(b) .a gear rack in mesh with said pinion gear,

(c) said gear rack being disposed for reciprocable movement relative said grapple means.

9. Loading apparatus in accordance with clam 8 including:

(a) .a heel boom structure for leveling a load held by said grapple means,

(b) said heel boom structure being pivotally supported between its ends to the free end of said boom assembly, and

(c) said first sleeve member being mounted on the end of said heel boom structure farther from said vertical axis for pivotal movement about a transverse .axis, whereby the other end of said heel boom structure can be forced downwardly to level a load held by said grapple means when said grapple means is in a r-otative position aligned w-ith said boom assembly.

10. Loading apparatus in .accordance with claim 6 in which:

(a) said cam means includes a lobe on said first sleeve member and a cooperable notch in said second sleeve member.

11. Loading |apparatus for articles requiring orientation which comprises:

55 (a) support means adapted to be moved into various spatial positions;

(b) first cam means mounted on said support means;

(c) load engaging means;

(d) means suspending said load engag'ing means from said support means for rotation about a generally Vertical axis and for limited longitudinal movement along said axis;

(e) second cam means mounted for movement with .said lload eng-aging means .and engageable with said first cam means to cause said load engaging means to assume a lpreferred r-otative position with respect to said support means, and

(f) means biasing said load engaging means upwardly to cause engagement of said respective cam means and hence to effect said preferred rotative position,

(g) whereby when said load engaging means engages a load of suflicient weight to overcome the action of said biasing means sa-id second cam means will be pulled downwar-dly to effect disengagement of said second cam means from said fir-st cam means.

9 10 12. Loading apparatus in accordance With claim 11 in means for loading elongated objects When held by which: said grapple.

(a) said second cam means is riotlatively adjustable rel- :ative to said load engaging means, and References Clfed by the Examlllel' (b) power means for atuating said second cam means 5 UNITED STATES PATENTS into la selected.rotat1ve-pos1mon t'o determine said 2672364 3/54 Ragland 294 82 preferred rotative posltlon of said load engagrng 2 685 974 8/54 Kern lsmanwh respe'ctttoaldsuponmef' 1 12 2,870,926 1/59 shock 214 147 0a rng appara us in accor ance Wi c a1m m 2303 146 9/59 Me10y which:

(a) said load engaging means includes a grapple, and (b) .a heel boom pivotally carried by said support HUGO O. SCHULZ, Primary Examiner.

10 3,038,620 6/62 Collins.

Claims

1. LOADING APPARATUS FOR ARTICLES REQUIRING ORIENTATION WHICH COMPRISES: (A) A BOOM ASSEMBLY SWINGABLE ABOUT A GENERALLY VERTICAL AXIS; (B) LOAD ENGAGING MEANS; (C) MEANS SUSPENDING SAID LOAD ENGAGING MEANS FROM THE FREE END OF SAID BOOM ASSEMBLY FOR ROTATION RELATIVE THERETO;