US3004674A

US3004674A - Swivel support for shovel boom

Info

Publication number: US3004674A
Application number: US740151A
Authority: US
Inventors: Robert M Griffith
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-06-05
Filing date: 1958-06-05
Publication date: 1961-10-17
Anticipated expiration: 1978-10-17

Description

Oct. 17, 1961 Filed June 5, 1958 R. M. GRIFFITH 3,004,674

SWIVEL SUPPORT FOR SHOVEL BOOM 3 Sheets-Sheet 1 Oct. 17, 1961 R. M. GRIFFITH SWIVEL SUPPORT FOR SHOVEL BOOM Filed June 5. 195s- 3 Sheets-Sheet 2 Nul N .Sl

Robert M. Griff/fh INVENTOR.

Oct. 17, 1961 R. M. GRIFFITH SWIVEL SUPPORT FOR SHOVEL BOOM 3 Sheets-Sheet 3 Filed June 5, 1958 Robert M. Griff/'fh 1N VEN TOR. wh. BY @ab uu/guay me!! UnitedStates Patent O f' Y 3,004,674 SWIVEL SUPPORT FOR SHOVEL BGOM Robert M. Griffith, Prineville, Oreg. (P.0. Box 621, McCloud, Calif.) Filed June 5, 1958, Ser. No. '740,151 15 Claims. (Cl. 212-425) This invention relates in general to new and useful improvenientsin shovel construction, and more particularly tol an improved shovel boom for use in conjunction with llog handling tongs.

At the present time conventional type shovels are being used in log handling operations. Such shovels have mounted on the boom sticks thereof log handling tongs which are so constructed whereby they will grasp the log and support the log for the necessary log handling operation'. However, there are many instances when it is necessary to pick a log up from a pile with the result that a side twist is placed on the log handling tongs. Such side twist is then transferred to the boom stick which causes a racking of the boom stick and a torsion or bending moment on the connection between the boom stick and the boom. Further, when the log is being moved about, any change of movement of the log, that-is acceleration orl deceleration ofthe log as itis swung, results in the racking ofthe boom stick. This is an undue strain for which the boom of a conventional shovelis not designed. As a result, the boom fails after a relatively short use and must be replaced or repaired at a relatively great expense to the owner. i

IIt is therefore the primary object tof this invention to provide an improved boom for shovels which is particularly adapted for use in a log handling operation, the

boom including a swivel supportI for the boom stick whereby the boom stick is free to twist duringl thelog handling operation so that no torsion in the boom stick results nor are torsional or bending moments transferred from the boom stick to the boom through the boom stick support,

Another object of this invention is to provide an improved boom for shovels to be used in log handling lopera tions, the boom including a boom support having slidably received therein a boom stick, the boom support supporting a swivel action of the boom stick as well as the sliding movement so that racking of the boom stick and the boom is prevented. .Y

'Still another object of this invention is to provide an improved boom construction for use in conjunction with shovels during a log handling operation, the boom construction including a swivel support for the boom stick, and there being provided a suitable crowd mechanism whereby the boom stick may be operated with respect to the boom in the normal manner and at the same time the racking of the boom stick and the boom is eliminated.

Another object of this invention is to provide an improved crowd mechanism for use in conjunction with a swivelly mlounted boom stick, the crowd mechanism including a pair of cables connected to opposite ends of the boom stick and being anchored by means of a drive mechanism which will simultaneously foreshorten one of the cables while paying out the other of the cables so that the boom stick may be moved in the desired direction through the support thereof carried by the boom.

A further object of this invention is to provide an irnproved crowd mechanism for use in conjunction with swivelly supported boom sticks of a shovel boom, the crowd mechanism including a rack on the boom stick and a pinion gear carried by the support for the boom .stick and engaged with the rack whereby through the pinion gear and the rack the boom stick may be extended or retracted as is desired. f

These together with other objects and advantages which Patented Oct. 17, 1961 ICC will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described, and claimed, reference being hadto the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout and in which: FIGURE 1 is a side elevational view of a shovel particularly adapted for a log handling operation and shows the particular boom structure which is the subject of this invention, the boom stick being provided with a -log handling tong assembly;

FIGURE 2 is an enlarged fragmentary sectional view taken substantially upon the plane indicated by the section line 2 2 of Figure 1 and shows the specific details of the connection between the boom stick and the boom, as well as the crowd mechanism for retracting and extending the boom stick with respect to the boom;

FIGURE 3 is an enlarged fragmentary sectional view taken substantially upon the plane indicated by the section line 3 3 of FIGURE 1 and shows the connection between the forward end of the boom stick and the log handling tong assembly;

FIGURE 4 is an enlarged fragmentary sectional view taken substantially upon the plane indicated by the section line 4--4 of FIGUREl :and shows the specific details of the swivel suppoit for the boom stick;

FIGURE 5 is an enlarged fragmentary vertical sectional view taken through a modified form of boom construction and shows the `specific details of another form of crowd mechanism;

FIGURE 6 is an enlarged fragmentary side elevational View of another form of boom assembly with portions of the boom thereof being broken away in order to illustrate the specific details of still another form of `crowd mechamsm; A Y

FIGURE 7 is an enlarged fragmentary sectional'view taken substantially upon the plane indicated by the'section line 7--7 of FIGURE 6 and shows further the details of the construction of the crowd mechanism;

FIGURE 8 is a fragmentary horizontal sectional View Von a large scale showing still another modified form of boom assembly, the View being similar to FIGURE 2 and shows the specific details of the boom assembly;

-FIGURE 9 is an enlarged fragmentary sectional vie taken through the boom stick support of the boom assembly of FIGURE 8 and shows thev specific details thereof;

FIGURE 10 is an enlarged fragmentary horizontal sectional view similar to FIGURE 8 and shows the details of still another form of boom assembly; and

FIGUIRE l1 is an enlarged perspective View of a boom stick 'supporting member of the boom stick support of FIGURE 10. Referring now to the drawings in detail, it will be seen that there is illustrated in FIGURE l a shovel which is re- .ferred to in general by the reference numeral 10, and

which is particularly adapted for use in a log handling operation. The shovel 10 includes a crane body 12 which has pivlotally connected to the lower forward part thereof the boom assembly which is the subject of this invention, the boom assembly being referred to in general bythe reference numeral 1-4. The boom assembly 14 includes a boom 16 which is pivotly connected to the crane body Vas at 18 and which is provided at the upper end thereof with suitable sheaves 20 over which there are entrained cables 22. The cables 22 are in turn entrained over sheaves,` 24 carried by `an A frame 26 mounted on the train body 12 to effect the raising and lowering of the boom 16.

Carried by an intermediate part of the boom 16 VisV a boom stick support, which is referred to in general bythe reference numeral 28. The boom stick support 28, in turn, supports a boom stick 30. Carried at the forward end of the boom stick 30 is a log handling tong assembly 32 which in itself plays no part in the present invention.

In order that the log handling tong assembly 32 may he raised andlowered to the pivoting of the boom stick 30, there is provided a't the upper end of the boom stick 16 sheaves 34 over which thereis entrained a cable 36. The cable 36 also passes over a sheave 38 carried 'by 'the ylog handling tong assembly. 32. The cable V36 terminates in the crane body 120m one of the drums (not shown) thereof.

Referring now to FIGURE 2 in particular, it will b Vseen that the boom 16 is formed of a pair of transversely spaced parallel boom members llwhich` :are `conr`nected together at spaced intervals by transverse members. The boom members V488 are illust-rated as being channel-shaped in cross-section, but may be of any desired configuration.

Referring now to FIGURE 4in particular, it will be seen that the boom stick support 28 includes an .outer fitting 42 which is rhollow and which `has extending .from opposite .sides thereof aligned trunions 44. The `tzt-unions 44 are rotatably journaled 'in suitable bearing assemblies 46 carried by the boom members 38. It is to be noted that the outer fitting 42 is spaced inwardly yof the boom members 38 for a reason to be set 4forth in more detail hereinafter.

Extending generally vertically through the outer support fitting 42 are aligned pivot members 48 which are :disposed normal to the axis of the trunnions 44. `Pivotally mounted on the pivot members 48 within the outer support fitting 42 is an inner support fitting 50. The inner support fitting 50 is provided with a bore 52 therethrough. The hoornA stick 30 conforms in crossvsection to the bore 52 and is slidably received therein;

From the foregoing -description of the boom stick support 28, it will be seen that the boom stick 30 is mounted for both sliding and rotational movement with respect piston (-not shown) to which there is connected an extensible piston rod 86. The piston rod 86 is conto the boom stick support 28 .and that the'boom :stick Y support 28 permits pivoting of the boom stick in a vertical plane passing through the boom 16 aswell as about an axis lying within that plane. the 'boom stick 30 is swivelly .mounted with .respect to the boom 16 rso that racking thereof is eliminated.

Referring now to FIGURE .3 in particular, it will be seen that the forward end of the boom stick 30 is bifurcated `to provide a pair of vertically spaced parallel plate portions 54. These plate .portions 54 are suitably secured to a casting 56 of the log handling tong assembly 32. Also extending through the plate portions 54 is 4a shaft forming member 58 on which there is mounted a generally horizontally disposed sheave 60. 'Ihe sheave 60 is disposed intermediate the plate portions 54 and is spaced therefrom -by means of spacers 62.

Referring once again to FIGURE 2 .in particular, it will be seen that carried by one of the transverse frame members is a sheave 64. Also, the `rear portion of the bucket stick (30 includes a pair l`of plate portions 66 similar to the plate portions 54 through which there passes a shaft forming member 68 supporting a sheave 70.

Anchored to the bucket stick support 28 as at 72 is one vend of a cable 74. The cable 74 passes about Ythe sheave 70 and is entrained over a sheave 76 which is rotatably journaled on one of the trunnions 44, as is best shown in FIGURE 4. 'Ihe cable 74 then passes about the sheaves 64 and is entrained over a sheave 78 carried by the other of the trunnions 44, as is also best shown in FIGURE 4. The cable 74 then passes about the sheave 60 and is finally anchored to the bucket stick support 28 as at 80.

Secured to one of the boom members 38 is a hydraulic motor of the extensible type, the hydraulic motor being referred to in .general Vby the reference numeral 82 and includes a cylinder 84 on which there is mounted a nected to an intermediate part of the cable 74 intermediate the

sheaves

64 and 78 by means of a fitting 88. The hydraulic motor 82V is of the double acting type and has connected lto opposite ends of the cylinder 84 thereof hydraulic lines .90 and 92 which fextend into the crane body 12 and lare `connected to a suitable pressurized hydraulic system (not shown).

By extending or retracting lthe 'piston rod 86, the bucket stick 30 may be extended or retracted with respect to the boom 1'6, as is desired. Thus the numerous sheaves described, the cable 74 and the fluid motor 82 combine to form a crowd mechanism which is referred to in general by the reference knumeral 94. lThis crowd mechanism will `be operated by suitable controls within the crane body 12.

At this time it is pointed out that Ythe log handling tong assembly 32 is operated by a hydraulic system which includes a pair of

hydraulic lines

96 and 98. rPhe

hydraulic lines

96 and 98 pass through the bucket stick 30, as is best shown in FIGURE 4 and are connected to the pressurized .hydraulic system within the crane 4body 12.

Referring now to FIGURE 5 in particular, it will be seen that there is illustrated a slightly modified form of crowd mechanism which is referred to in .general .by the reference numeral A100. I The crowd mechanism -100 is mounted lon a boom 102 which lis identical with the boom 16 and is connected to a-boom stick 104 which is identical with the boom stick l30. Also, the boom stick 104 is supported relative to the boom 102 by means of a boom stick support 1.06 which is identical to the boom stick support 28.

The boom 102 includes a pair of spaced parallel boom members 108 which have extending therebetween a shaft 110 which has the opposite ends thereof journaled in suitable bearing assemblies 112 carried by the boom members 108. The shaft 110 has drums 1'14 and 116 mounted thereon.

Carried by the boom members 108 yand extending therebetween is a plate 118. The plate 118 has mounted thereon a hydraulic motor 120 of the rotary type which includes a drive shaft 122 'on which there is mounted a sprocket '124. Aligned with the sprocket l124 is a sprocket 126 .carried by an input shaft 128 of a reduction Vgear unit 130. Connecting together the

sprockets

124 and 126 is a drive chain 132. VThe vreduction gear unit 130 is mounted on the plate 118.

The reduction gear unit 130 also includes an l.output shaft '134 on which there is mounted a sprocket36. 'The sprocket 136 is aligned with the sprocket 138 and is drivingly Vconnected thereto by ymeans `of a drive 'chain 140.

In order that the hydraulic motor 120 may be driven, there is provided suitable .hydraulic lines VV142 which will be connected to the pressurized hydraulic suppply of the crane body 12. Suitable controls will be .provided within the frame body 12.

Reeled yon the drum 114 is la cable 144 which corresponds to the forward part of the cable 74. Reeled on the drum 116 is a cable l146 which corresponds to the rear half of the cable 74. Thus the crowd mechanism 100 'will operate lin the same general manner as the crowd mechanism 94, but will be driven by a :different type of drive mechanism.

Referring lnow to FIGURES 6 and 7 in particular, it will be seen that there is illustrated a modified form of boom assembly which is referred to in general by the reference numeral 148. The boom assembly 148 includes a boom 150 which is identical with the boom 16. Carried by the boom 150 is a boom stick support 152. The boom stick support 152 in turn carries `a boomstick 154. e

ano/1,6%

The boom stick support 152V is very similar to the boom stick support 28 and includes an outer support fitting 156 which will be identical with the outer support fitting 42.V Pivotally mounted Within the outer support fitting 152 by pivot members identical to pivot members 48 in FIGURE 4, is an inner support tting 158, the bottom pivot member head being visible in FIGURE 7, while the heads of both pivot members being visible in FIGURE 6. The inner support fitting 158 differs from the inner support fitting 50 primarily in that it is of a greater4 length that the inner support fitting 50 and in lieu of a bore 52 it is provided with a partial bore 160, as is best shown in FIGURE 7, which opens into an enlarged opening 162in the bottom part of the inner support fitting 158.

The boom stick 154 differs from the boom stick 3i) only in that there is secured to the underside thereof an elongated rack 164. It is the purpose of the opening 162 to provide clearance for the rack 164 and thus provide for limited rotation of the boom stick 160 relative to the inner support fitting 158.

Extending transversely `of the inner support fitting 158 and supported thereby is a shaft 166. The shaft 166 is provided with a pinion gear 168. The pinion gear 168 is meshed with the rack 164 to effect the extension and retraction of the boom stick 160 as desired. The rack 164 has a relatively wide circumferential eX- tent so as to permit a slight rotation of the boom stick 160 within the inner support fitting 158.

In order that the shaft 166 may be driven, there is mounted on the upper rear part of the inner support fitting 158 a reduction gear unit 170 to which there is connected a rotary hydraulic motor 172. The reduction gear unit 170 is provided with an output shaft 174 disposed parallel to the shaft 166. The output shaft 174 carries a sprocket 176 which is aligned with a sprocket 178 on the shaft 166. The

sprockets

176 and 178 are connected together by a drive chain 180.

The hydraulic motor 172 is provided with suitable hydraulic fluid supply lines 182. The hydraulic iiuid supply lines 182 will. be connected to the pressurized hydraulic supply system of the cranebody 12. Suitable controls will be provided to facilitate the operation of the crowd mechanism, which crowd mechanism will be referred to in general by the reference numeral 184.

Referring now to FIGURES l and ll in particular, it will be seen that there is illustrated a modified form of boom stick support which is referred to in general by the reference numeral 186. The boom stick support 186 may be mounted in the boom 16'in the manner described above with respect to the boom stick support 28. However, the construction of the boom stick support 186 differs from that of the boom stick support 28.

The boom stick support 186 includes a two-piece outer support fitting 188 which is` provided with suitable trunnions 190 which journal the outer support fitting 188 in the boom 16. The internal construction of the outer support fitting 188 is such to provide a partial spherical socket 4192 inV which there 'is positioned a partial spherical member 194 which forms a part ofthe inner support fitting 196. The inner support fitting 196 is best illustrated in FIGURE ll and includes an elongated sleeve portion 198 through which the boom stick 200 passes. At this time it is pointed out that the boom stick 200 is illustrated as being square and the sleeve 198 as having a square cross-sectional opening therethrough. It is not necessary that the boom stick 200 rotate relative to the inner support fitting 196. However, the cross-section of the boom stick 200 may be that desired.

The crowd mechanism utilized in conjunction with the boom stick support 186 may vary as desired and may be any one of those illustrated in FIGURES 2, and 6.

Referring now to FIGURES 8 and 9 in particular, it will be seen that there is illustrated a modified form of boom assembly which is referred to in general by the reference numeral 202. The boom assembly 202 utilizes a boom identical with the boom 16. The boom assembly 202, however, utilizes a modified form of boom support 204 and a modified form of boom stick The boom stick support` 204 includes an outer support fitting 208 which is identical with the outer support fitting 188. The outer support fitting 208 is suitably journaled in the bearing units 46 of the boom 16. Swivelly` mounted in the outer support fitting 208 .is a modified form of inner support fitting 210. The inner support fitting 210 includes a generally spherical par-t 212 in which there is formed a pair of sleeve portions 214. VThe sleeve portions 214,have.extending therebetween a shaft 216 on which there are journaled sheaves 218 and 220'which correspond to -the sheaves 78 and-76, respectively.'

The boom stick 206 includes at pair of spaced parallel members 222 which are connected together at their rear ends by a member 224 and which have their forward ends connected to` the log handling tong assembly32. The sections 222 are slidably disposed in the sleeves 214, as is best illustrated in FIGURE 9.

The member 224 is provided with a shaft 226 which carries a sheave 228. The sheave 228 Vcorresponds to the sheave 70. i, 2 i

Connected to the bottom 16 'andv theboom stick 206 is a crowd mechanism which is referred to in general by the Ireference numeral 230 and which, with the exception of the particular placements of the sheaves 218, 220 and'228, is identical Vto the crown ,mechanism of FIG- UREV 5. Accordingly, a further description of the crowd mechanism is believed to be unnecessary.

From the foregoing description of the present invention, it will be seen that there have been devised several forms of boom assemblies which include various forms of crowd assemblies, which boom assemblies are such in nature whereby pivoting and twisting of thebooin stick is permitted with respect to the boom in order to prevent racking of the boom stick and the-connection between the boom stick and the boom. Also, the crowd mechanisms are of such a nature wherebythe boom stick may be extendedY and `retracted as is necessary in the operation thereof.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modificationsand equivalents may be resorted to, falling within the scope of the invention as claimed.

vWhat is claimed as new is as follows: Y n

1. A log handling boom assembly for shovels, said boom assembly comprisingva boom, a support tting mounted on said boom intermediate the Vends thereof, a boom stick supported by said support fitting including means for universally pivotally mounting and slidably receiving said boom stick while permitting free lateral displacement thereof, and crowd means carried by said support fitting and said boom stick for advancing and retracting said boom stick through said support fitting.

2. A log handling boom assembly forshovels, said boom assembly comprising a boom, a support fitting mounted on said boom intermediate the ends thereof, a boom stick supported by said support fitting including means for universally pivotally mounting and slidably receiving said boom stick while permitting free lateral displacement thereof, and crowd means carried by said support fitting and said boom stick for advancing and retracting said boom stick through said support fitting, said crowd means including a hydraulic drive unit.

3.A log handling boom assembly for shovels, said boom assembly comprising a boom, a support fitting mounted on said boom intermediate the ends thereof,V a boom'stick supported by said support fitting for sliding and pivotal movement, and crowd means carried by said support fitting and said boom stick for advancing and retracting `said boom stick through said support fitting, said support fitting including anouter support fitting and first support means mounting said outer support fitting for pivotal movement in a vertical plane passing through said boom, an inner support fitting, second support means pivotally mounting said inner support fitting for pivotal movement relative to said outer support fitting.Y

4. A log handling boom assembly for shovels, said boom assembly comprising a boom, a support fitting mounted on said boom intermediate the ends thereof, a boom stick supported by said support fitting for sliding and pivotal movement, and crowd means carried by said support fitting and said boom stick for advancing land retracting said boom stick through said support fitting, saidsupport fitting including an outer support fitting and first support means mounting said outer support fitting for pivotal movement in a vertical plane passing through said boom, an inner support fitting, second support means pivotally mounting said inner support fitting for pivotal movement relative to said outer support fit-ting, said inner support fitting including a sleeve portion, said boom stick corresponding in cross-section to said sleeve portion and slidable therethrough.

5. The combination of claim 4 wherein said crowd means includes a rack on said boom stick and a drive pinion supported by said support fitting. t

6. A log handling boom assembly for shovels, said boom -assembly comprising a boom, a support `fitting mounted on said boom intermediate the ends thereof, a boom stick supported by said support fitting including means for universally pivotally mounting and slidably receiving said boom stick while permitting free lateral displacement thereof, and crowd means carried by said support fitting and said boom stick for advancing and retracting said boom stick through said support fitting, said crowd means including a pair ofcables,'one of said cables being connected to one end of said boom stick, the other of said cables being connected to the opposite end of said'boom stick, anddrive means connected to said cables for simultaneously paying out on one of said cables while reeving in on the other.

7. A log handling boom -assembly for shovels, said boom assembly comprising a boom, a support fitting mounted on said boom intermediate the ends thereof, a boom stick supported by said support fitting including means for universally pivotally mounting and slidably receiving said boom stick While permitting free lateral displacement thereof, and'crowd means carried by Vsaid support fitting and said boom stick for advancing and retracting said boom stick through Vsaid support fitting, said crowd means including a pair of cables, one of said cables being connected to one end of said boom stick, the other of said cables being connected to the opposite end of sai-d lboom stick,and drive means connected to said cables for vsimultaneously paying out on one of said cables while reeving in on the other, said -drive means being mounted on said boom. Y

8. AAlog hand-ling boom assembly for shovels, said boom assembly comprising `a boom, a support 'fitting mounted on `said boom intermediate the ends thereof, a boom stick supported by said support fitting including means 'for universally pivotally mounting and slidably receiving said boom stick while permitting free lateral displacement thereof, and crowd means carried by said support fitting and said boom stick for advancing and retracting said boom Lstick through said support ffitting, said crowd means including arpair of cables, one of said cables being connected to one gend of said boom stick, the other of said cables being connected to the opposite end of said boom stick, and drive means connected to said cables for simultaneously paying out `on oneV of sai-d cables 'while reeving in on the other, said support lfitting including trunnions extending transversely of said boom .8 sheaves carried by said trunnions, said cables passing over said trunnions, said drive means being mounted on said boom. i'

9. A loghandling boom assembly for shovels, said boom assembly comprising a boom, a support fitting mounted on said boom intermediate the ends thereof, a boom stick supported by said support fitting for sliding and pivotal movement, and .crowd means carried by said support fitting and said boom stick for advancing and reti-acting said boom stick through said support fitting, said support fitting including an outer support fitting and first support means mounting saidouter support fitting for pivotal movement in a vertical piane passing through said boom, an inner support fitting, second support means pivotally mounting said inner support fitting for pivotal movement relative to said outer support fitting, said second support means being in the formk of a universal swivel fitting. t

l0. A log handling boom assembly for shovels, said boom assembly comprising a boom, a support fitting mounted on said boom intermediate the ends thereof, a boom stick supported by said support fitting universally pivotally mounting and slidably receiving said boom stick whilel permitting free lateral displacement thereof, and crowd means carried by said support fittingA and said boom stick for advancing and retracting said boom stick through said support fitting, said crowd means including a drive unit mounted on said boom.

l1. A log handling boom assembly for shovels, said boom assembly comprising a boom, Va support Vfitting mounted on said boom intermediate the ends thereof, a boom stick supported by said support fitting for sliding and universal pivotal movement, and crowd means carried by said support fitting and said boom stick for advancing and retracting said boom stick through said support fitting, said support fitting including an outer sup port fitting and rst support means mounting said outer support fitting for pivotal movement in a vertical plane passing through said boom, an inner support fitting, secondsupport means pivotally mounting said inner support fitting for pivotal movement relative to said outer support fitting, said crowd means including a pair of cables, one of said cables being connected to one end of said boom stick, the other of said cables being connected to the opposite end of said boom stick, and drive means connected to said cables for simultaneously paying out on one of said cables while reeving in on the other.

12. A log handling boom assembly for shovels, said boom assembly comprising a boom, a support fitting mounting on said boomV intermediate the ends thereof, a boom stick supporte/:l by said support fitting for sliding and pivotal movement, and crowd means carried by said support fitting and said boom stickfor advancing andretracting said boom stick through said support fitting, said supportfittingY including an outer support fitting and first support means mounting said outer support fitting for pivotal movement in a Vertical plane passing through said boom, an inner support fitting, a second support means pivotally mounting said inner support fitting for pivotal movement relative to said outer support fitting, said vsecond support means being in the form .of a universal swivel fitting, `said crowd means including a pau' of cables, one of said cables being connected to one .end of said boom stick, the other of said cables 'being ,connected to the opposite'ends of said boom stick, and `drive means connected to -said cables for simultaneously paying out on one of said cables while reeving in on the other.

13. A log handling boom assembly for shovels, said boom assembly Vcomygnising a boom, a support fitting mountingV on said boom intermediate the ends thereof, a boom stick supported by said ysupport `fitting for sllding and pivotal movement, .and Vcrowdmeans carried -by said support fitting and said boom stick for advancing and retracting said 'boom 'stick through said, support fitting, said support fitting including an outer support titting for pivotal movement in a vertical plane passing through said boom, an inner support iitting, a second support means pivotally mounting said inner support tting for pivotal movement relative to said outer support itting, said second support means being in the form oi a universal swivel tting, said crowd means including a pair of cables, one of said cables being connected to one end of said boom stick, the other of said cables being connected to the opposite ends of said boom stick, and drive means connected to said cables for simultaneously paying out on one of said cables While reeving in on the other, said support fitting including trunnions extending transversely of said boom, sheaves carried by said trunnions, said cables passing over said trunnions, said drive means being mounted on said boom.

14. A log handling boom assembly for shovels or the like, comprising a boom, a boom stick, supporting means mounted on said boom for universally pivotally mounting and slidably receiving said boom stick while permitting free lateral displacement thereof, and mechanism operatively connected to said supporting means and boom stick for effecting sliding movement of said boom stick relative to said supporting means.

15. The assembly as dened in claim 14, wherein said mechanism includes means anchored to said supporting means for effecting the sliding movement of said boom stick and a power source mounted externally of the assembly for energizing said mechanism.

References Cited in the le of this patent UNITED STATES PATENTS Re. 21,405 Stiehl Mar. 19, 1940 1,907,442 Rauch May 9, 1933 2,569,458 Davidson Oct. 2, 1951