US2405578A

US2405578A - Hoisting apparatus

Info

Publication number: US2405578A
Application number: US528314A
Authority: US
Inventors: Strang S Bartow
Original assignee: Ernest Holmes Co
Current assignee: Ernest Holmes Co
Priority date: 1944-03-27
Filing date: 1944-03-27
Publication date: 1946-08-13
Anticipated expiration: 1963-08-13

Description

E.. W. HOLMES HOISTING APPARATUS FiledMarch 27,1944 s sheets-sheet 1 IIIIIIILIIHH hun "PHL" llllll lllll j Emmi MMM@ Aug. H 1946. l E. w. HOLMES .2,405,573 I' HoIs'TING APPARATUS Filed March 27, 1 944 e sneets-sneptz ug. 13, 1946. E. w. HOLMES HOI S TING APPARATUS Filed Maron 27., '1944 e sheets-sheet 5 Aug. 13,l 1946,

E. W. HOLMES HOISTING APPARATUS ug. i3, 1946. y E. w. HOLMES 2,405,573

.HOISTING APPARATUS l Filed-March 27, 1944 esheets-sheet 5 u J J J v J u l u z u J M Aug E3, i946. vE. w. HOLMES u y 2,405,578

HOISTING APPARATUS Filed March 27, 194A 6 Sheets-Sheet 6 j? v f5.5

gmac/Mofa A mw Pff/262m@ j B342@ la Wg Patented Aug. 131, 1946 HOISTIN G APPARATUS Ernest W. Holmes, Chattanooga,

Tenn.; S.

Bartow Strang, administrator of said Ernest W. Holmes, deceased, assigner to Ernest Holmes Company, Chattanooga, Tenn., a corporation of Tennessee Application March 27, 1944, Serial No. 528,314

20 Claims. 1

The present invention reiates to improvements in hoisting apparatus, and more especially to wreckers of the type employed for handling disabled automotive and other vehicles and for other uses where hoisting, pulling, towing or similar operations are to be performed.

One of the primary objects of the invention is to provide novel and improved operating and controlling mechanism for the cable winding drums whereby the construction thereof is simplified and improved and the operation thereof is facilitated.

Another object is to provide novel and improved driving mechanism for the cable winding drums of apparatus of this character, and partie ularly wreckers, of the double boom type in which each boom has a drum for the boom cable and a drum for the hoisting or service cable, whereby one or more or all of the drums may be operated at any time under control of a single attendant and from a single power drive.

Another object of the present invention is to provide novel and improved hoisting apparatus which, when mounted on a wrecking truck or other vehicle, is readily accessible' as to all of its 4parts for inspection or servicing.

Another object is to provide a novel and improved frame in which the mechanism of the hoisting apparatus is accommodated compactly and jwhich enables narrow hoisting drums of large diameter to be used, with the advantage that fewer layers of cable requireto be wound thereon for a cable of given length than heretofore, and thereby avoiding or minimizing wedging of the cable between convolutions of a lower layer thereof, as frequently takes place in winding a large number of layers of a tensioned cable upon a drum, the frame being so designed that such narrow large diameter drums may be readily removed edgewisetherefrom, should such become necessary for servicing or other purposes. Further objects of the invention are to provide a novel and improved construction of driving mechanism for the cable drums which facilitates the manufacture thereof, minimizes stresses I thereon under load, enables the parts thereof to be 'readily removed for servicing or other purposes, and which is otherwise well adapted to meet al1 of the requirements of heavy-duty apparatus of this type.

ATo these and other ends, the invention consists in certain improvements, and combinations and arrangements of parts, all as will be hereinafter more fully described, the features of novelty being pointed out more particularly in the claims at the end of this specification.

In the accompanying drawings,

vention, the same being shown mounted on a truck and adapted to be employed as a wrecker;

Figure 2 is a top plan View ofa portion `of the apparatus shown in Figure 1;

Figures 3 and 3a are collectively a rear elevation of the apparatus on an enlarged scale, the booms being shown as swung from the opposite sides of the truck;

Figure 4 is a/detail View of one of the slings for the upper ends of the booms:

Figure 5 is adetail view in vertical section of the driving gearing for the boom and service cables of one of the booms;

Figure 6 is an elevation of the gearing as viewed from the right in Figure 5;

Figure 7 is a detail horizontal section taken on the line 1 1 in Figure 6; f

Figure 8 is an elevation of the transferVV or` transmission mechanism through which the driving gearings for the booms and the service cables are driven;

Figure 9 is a plan View of the transfer mechanism, with the cover thereof removed and parts shown in section;

Figure 10 is a section taken on the line lll-l0 f in Figure 8;

Figure 11 is an enlarged detailelevation of the lower portion of one side of the frame, showing the drums for the service and boom cables;

Figure 12 is a rear elevation of the structure Figure 14 is a detail view showing the manner of attaching the sling to the sheave yoke at the upper end of the boom;

Figures 15 and 16 are detail sectional views showing the mountings of the swivels for the boom cable guide sheave and the boom respectively; and

Figure 17 is a detail horizontal section on the line l1|1 in Fig. 11.

Similar parts are designated by the same reference characters in the several figures.

The hoisting apparatus, according to the present invention, comprises a frame l, a pair of swinging boomsl 2, and cable winding drums and ydriving mechanism therefor which form a complete unit. As shown in Figure 1,v this unit is a* adapted to be mounted on the chassis 3 of a motor truck so that the frame of the hoisting apparatus extends transversely of the truck immediately behind the drivers cab 4, all of the parts of the hoisting mechanism being readily accessiblefromf the rear and sides of the frame, as will hereinafter appear.

The frame I comprises a pair of parallel, spaced vertical columns 5 at each side, each column being composed preferably of channel iron, a pair of horizontal base members 6, also preferably composed of channel iron, to the outer sides of which the lower ends of the columns 5 are riveted, welded or otherwise iixed and a similar pair of horizontal members I connecting the respective columns 5 and similarly iixed thereto. Angle irons 8 extend horizontally between and connect the tops and diagonal braces S connect the ends `or the upper angle irons and plates IU riveted,

welded or Aotherwise xed to the lower portions of the columns 5. rlhe frame is supported rigidly on the truck chassis.

The booms 2 are each pivoted on a horizontal pivot' I I carried by a swivel I2 having a vertical stem I3 tted rotatably in upper and lower plates I4 bolted, welded or otherwise xed to the top ,and bottom respectively of the base members t spanning the space between them, the booms being thus mounted to swing upwardly and down- Wardly about the horizontal pivot I I and to swing laterally about the vertical stem I3 as an axis. The upper end of each boom is provided with a sheave l5l over which the hoisting or service cable I6 passes, this cable being equipped at its 'end with a hook Il or other suitable means for engaging it with an automobile 'or other vehicle' or object to be hoisted or hauled, the sheave being journaled on a horizontal shaft I3 in a yoke i9 swiveled in the upper end of the boom, a cable guide I?!a being connected to this yoke for causing it to swivel in the end of theboom when a load isr being pulled from either side thereof. The upper end of each boom is also equipped with means'vfor attaching a boom'cable Ythereto for raising and lowering it. The boom cable is attached at one end by a pin 2l to a sheave carrier 22, the latter Abeing pivoted by the horizontal pin 23 to a swivel 24, the'latter having a hollow vertical stem 25 which is mounted rotatably in plates 26 which span the spaces betweenand are bolted, riveted, welded or otherwise fixed to the tops of the angle irons 8 and the upper and loweredges of the channel irons '1. Each sheave carrierhas a sheave 21 journaled therein, around which the boom cable passes, the boom cable also passing around a pair of sheaves 28 journaled on a pin 29 in a yoke 30.

The present invention provides novel means for attaching the boom cable yoke 30 to the upper end of the boom whereby the load on the boom'will be distributed and sustained equally at opposite sides of the service sheave I5, and such attaching means will avoid fouling with the upper end of the boom when the latter is raised. Such attaching means comprises a yoke 3I which is hooked by its intermediate portion in the yoke 30 and carries a pair of sheaves 32 which are journaled on a pin S3 in the'yoke 3 l. The sheaves '32 are connected to the upper end of the boom by a sling composed of a suitable length of ilexible cable 34 the ends of which are connected to form a loop, the intermediate portions of the loop being passed around the respective sheaves 32 and the ends of 'the loop being passed around groved segmental bosses 35 on the outer sides of CII the yoke I9, the pivot pin I8 for the service sheave passing through these bosses and being removable without disturbing the support of the boom by the sling. Clamps 35 are preferably employed to bind together the ends of the loop adjacent to the sheave pin I8. By this arrangement, the load on the boom is divided between and sustained by the ends of the sling at opposite sides of the service sheave, and the portions of the load sustained by the ends of the sling are equalized by the sheaves 32, especially when the yoke i9 swivels in the upper end of the boom, as takes place while the service cable is pulling a load from a side of the boom, thus equalizing the tension on all of the boom supporting cables. The ends of the sling straddle the upper end of the boom as'the latter is raised, as shown in Figure 3a, thus avoiding interference with the raising of the boom to its extreme height. An Outrigger leg 4!) is preferably provided for supporting the load on one or the other side of the frame while the boom at that side of the frame is swung laterally from the truck to lift a load at a side thereof. Each of these legs, as shown, comprises a pair of telescopic sections 4I and 42 adapted to be held adjusted to different lengths by a pin 43 which may be inserted through holes in the section 4I and the appropriate pair of opposite holes 44 spaced longitudinally of the section 42. The lower section Vof the leg is provided with a foot I2a to bear on the ground Ywhen the leg is extended laterally of the truck and the section 42 lowered. The upper section of the leg is pivoted on a horizontal pin 45 in a swivel .16 and the latter is provided with a vertical stem or journal which is rotatable in plates 23 and 25a spanning the space between and secured to the frame members 1. The universal pivoting of the legs 20 to the frame enables each leg to be extended at any angle laterally from the truck, as shown in Figure 3, to bring it beneath the respective boom and sustain a side pull or load, spreading of the lower end of the leg being prevented by a chain 41 which may be attached to lthe lower end of the leg and one of the base members of the frame, and when the leg is not in use it may be folded against a side of the truck, as shown in Figure 3a, and locked by a spring plunger 4B.

The service cable extends from the boom sheave IS over a sheave 50 journalled in a swivel 5I' having a 4hollow vertical stem 52 rotatably mounted in a pair of the plates 2S of the frame, this cable passing through the stem 52 and winding on a hoisting or service drum 55. The boom cable passes from one of the sheaves 28 over a. f

sheave 5l and downwardly through the respective swivel stem 25, then around a guide sheave 58 and winds on a drum 59.

Each service cable drum 55 is of relatively large diameter and of relatively short axial length, thus enabling a given length of cable to be wound thereon with a fewer number or lay ers of the cable than is possible with a drum of relatively small diameter, thus avoiding tendency of the service cable, while under load, to become wedged between convolutions of an underlying layer, and the narrow dimension of the drum enables it to be accommodatedl between the upright columns 5 at the respective sides of the frame. This drum 55 is mounted to rotate on or with a shaft 5B supported in bearings 60 in the relatively fixed plates I0 and from which it is removable axially, and the drum 55 carries a driving gear SI which meshes with a pinion 62 loOSe- 1y mounted on a driving-shaft 63 and is coupled thereto by splines |63 and a clutch collar |63a slidable thereon, the shaft 63 being journaled in bearings 64 supported by the plates |0, and being removably retained in said bearings by a plate l 638L secured to. the end of the shaft 63 by a cap screw 63h. A band brake 65 is preferably provided for controlling the slack in the service cable, this brake extending partly around the gear 6| and being drawn into frictional engagement with it by a tension spring 66, one end of which is attached to the frame and the other end of which is connected to an arm 6`| fixed to and projecting radially from a shaft 68, the vlatter being mounted rotatably in the columns 5 of the frame and having a yoke 69 fixed thereon and connected to one end of the brake band 65, the other end of this band being connectedfat'f to a suitable part' of the frame. A loop extends radially from the shaft 68 and is urged toward the portion of the service cable between the drum and the sheave 50. While theservice cable is under tension, as while a load is'thereon or this cable is being pulled to unwind it from the drum, it will engage or swing the loop to rotate the shaft 68 against the action of the spring 66 and in a direction to release the brake band 65 from the gear'l and thus avoid a drag upon the drum during lifting or lowering a load or while the service cable is being pulled manually from the drum,.but as soon as the service cable becomes slack, the loop deflects the cable under the actionof the spring 66 and the latter rotates the shaft 68 in a direction to frictionally engage the brake band 65 with the periphery of the gear 6|, thus avoiding over-running of the drum and consequent disarrangement of the cable thereon,

The drum 59 for winding the boom cable is removably mounted, by splines 59a, on a shaft '|5 which is journaled in bearings 'I6 supported by the relatively xed frame plates I9, and removably retained therein by a plate |6a secured to the end of the shaft 15 by a cap screw 15a.

' vThe pinion shaft 63 for driving the service cable drum and the shaft '|5 on which the boom cable drum is splined extend rearwardly from the frame and have worm wheelsv Tl and "I8 respectively keyed or otherwise removably v'fixed thereon for driving them in relatively opposite directions to wind lthe cables on the

respective drums

55 and 59. According tothe present invention, the worm wheel meshes with a worm 19 keyed or otherwise xed on a shaft 80, and the worm vwheel 18 meshes with a worm 8| keyed or otherwise fixed on a shaft 82 adjacent and parallel to the shaft 80. The worm shafts 80 and'82, which are driven in relatively opposite directions, are mounted in bearings 83 which sustain the radial and axial loads on these shafts, these bearings being preferably of theV annular ball bearing type and mounted removably in a casing 84 which contains or encloses the worm wheels" and 18, this ycasing having bearings 85 in which the shafts 63vand '|5 carrying the worm wheels are journaled. By so mounting the worm shafts in the casing and providing the casing with bearings for the worm wheel shafts, the casing and worm shafts are supported on or suspended from vthe worm wheel shafts independently of the main frame I, and by removably mounting the drum 59 on the shaft '|5 and removably mount- -ing the pinion 62 on the shaft 63,v the casing 84 together with thev worm gearing therein can be removed as aunit after the plates 63a and 16a have beenremoved and the torque screws 96 and 6. 91 loosened,4 for inspection or repair of these units or adjacent parts in the frame. As the cable winding drum is mounted rotatably on the shaft 56 and the latter is removable axially from its bearingsdn the plates I6, this drum may be readily removed edgewise from the adjacent side of the frame after removal of its shaft. The torque reaction between the casing 84 and the worm wheel or '|8 while being driven by its respective worm is sustained by thrust screws 96 and 9`| which are adjustable in brackets 498 and 99 xed to the rear side of the main frame, these screws being adjusted to bear against the resective ends of the casing 8.4, although, while -both worm wheels are being driven simultaneously, the torque reaction upon the casing 84 in one direction will neutralize the torque reaction thereon in the other direction, due to the opposite directions of rotation of the worm wheels 11 and 18. l Y The casing 84 is preferably composed of a pair of duplicate halves 84a and 84h united by anges 86 which may be bolted together, as shown, this design of the casing enabling a single pattern to be used for both and otherwise facilitating the manufacture thereof. The bearings83 for the worm shafts are removable axially, thus enabling the worm shafts and theworms thereon,l which are of smaller diameter than the bearings, to be removed axially from the casing for servicing or replacement.` The bearings 83 are retained in the casing by end plates 8l which are bolted or otherwise removably secured thereon, these end plates sustaining the end thrust of the Worms.' In order to prevent unintentional lowering of the boom or unwinding of the service cable, due to tendency of the worm gearing to back off under a load, because of the low resistance of the anti-friction bearings for the worms, each of the

worm shafts

86 and 82 which operate the service and boom cable drums 55 and 59 respectively is preferably provided with a friction brake which will prevent unwinding of the service or boom cable from its respective drum, but will not interfere with the normal lifting and lowering operations of these cables. Each friction brake comprises, in the present instance, a friction cone 90 which is keyed on the' respective worm shaft and abuts against a shoulder 9| thereon, and an outer cone 92 which is movable axially on the worm shaft and is urged against the cone 96 by a compressed coil spring 93 which encircles the worm shaft. The periphery of the outer cone92 is provided with a pair of axially extending ribs 94 between which a pin95 threaded into the casing projects, this pin and the ribs .permitting axial movement of the outer cone 92 but preventing rotation thereof, whereby the reaction off the frictional braking torque applied to the Worm shaft by the inner cone 98 will'be sustained. The present invention provides novel and improved transfer orv transmission mechanism whereby power may be applied to either service or boom drum or to any number or all of these drums, as may be desired. Such mechanism, as shown in the present instance, comprises pairs of axially alined shafts |09 and |0| journaled in bearings |92 and |83 respectively, which are bolted or otherwise rigidly fixed in the opposite side walls of a casing |04 having a removable cover |649. `The outer vends of the shafts |60 are connected by couplings |66 to the worm shafts 80 which drive the drums 55 for the service cables for the respective booms, and the outer ends 'of 7 the shafts IDI are connected by couplings |01 to the worm shafts 82 which drive the drums 59 for the boom cables for the respectivebooms. The inner ends of the shafts have jaw clutch members .|08 and |09 splined thereon to shift axially although connected to rotate therewith, and the inner ends of the shafts |0| have similar jaw clutch members |I0 and ||I splined thereon to shift axially although connected to rotate therewith. A shaft ||2 is interposed between the inner ends of the shafts |0| in axial alinement therewith, the ends of this shaft being reduced and journaled rotatably in the inner ends of theshafts |0|, and the shaft IIZ has a jaw clutch member I i3 and a gear I I4 keyed or otherwise fixed thereon, the gear I|4 having jaw clutch teeth ||5 fixed thereon, the clutch member I3 and clutch teeth |I5 being companions tothe clutch members ||0 and III respectively, and being engageable therebtT to connect the shaft ||2 to the respective shafts |0I. A shaft |16 similar to the shaft II2 is interposed between the inner ends of the shafts |00 in axial alinement therewith, and has reduced ends journaled rotatably in the inner ends of the shafts |00, and the shaft ||6 has a jaw clutch member I I1 and a gear I I8 keyed or otherwise fixed thereon, the gear ||8 having clutch teeth ||9 thereon, the clutch member ||1 and the clutch teeth on the gear ||0 being companions to the clutch b members |00 and |09 respectively, and being engageable thereby to connect the shaft I|6 to the respective shafts |90. Power is applied to the shaft ||2 by a shaft |20 which is journaled in a bearing |2| bolted or otherwise fixed in an end wall of the casing |04, the shafts ||2 and |20 being connected by bevel gears |22 and |23 keyed or otherwise xed to the respective shafts, and the gears ||4 and ||8 fixed on the shafts H2 and 6 mesh with one another whereby the shaft I I6 is driven from the shaft I I2 but in the opposite direction of rotation. The shaft preferably receives power for rotating it in one or the other direction for lifting or lowering operations from any suitable or well known form of power take-olf from the usual truck engine, as, for example, from asprocket wheel |24 driven in one or the other direction by any usual or conventional form of reversible power take-off from the transmission |25 of the truck, a chain f |26 driven fromv said sprocket wheel, and a sprocket Wheel |21 fixed to the shaft |20. p Thefour jaw clutches thus provided in the transfer` mechanism enable any one or more or all of the shafts |00 and |0| to be driven by power from the single power shaft |20, and meansris provided for controlling these clutches from a remote point, preferably the cab of the truck. Such controlling means, as shown in the present instance, comprises a set of Bowden wires I3I, |32, |33 and |34, the outer tubes or casings of which areheld, kas bya clamp |35, on thedtop of the casing |04 .and the inner wires of whichextend into the cab where they arevconnected to levers, knobs or other appropriate control members within convenient reach of an attendant in the cab. The other ends of the wires are operatively connected to levers |30, 31, |38 and |39 above the cover |04a of the casing |04, these levers being xed to the upper rends of shafts |49, '|4I, |42 and |43, respectively, journaled in suitable bearings in the casing |04. The shafts |40, I4I, |42 and |43 have forks |44,'|45, |46 and |41, respectively, xed thereon, these forks cooperating with grooved collars on the sliding clutch members |08, |09, ||0 and ||I, re-` spectively, whereby rotation of each shaft in one or the other direction by pulling or pushing its respective Bowden wire .will slide the respective sliding clutch member into or out of engagement with its companion clutch member. Means is preferably provided for yieldingly retaining each sliding clutch memberv in engaged or disengaged position, such means, in the present instance, comprising a bowed spring |48 pivotally connected at one end to a hook |49 fixedin the` adjacent end of the casing |04 and pivotally connected at its other end to a pin |50 fixed in the respective clutch shifting fork. The spring |48 normally tends to contract or close, thereby biasing ,the pin |50 on the respective clutch shifting fork in a direction toward the hook |49, and the hook |49 and pin |50 are so located on opposite sides of the respective clutch shifting Shaft that the pin |50 will move to one or the other side of a dead center position as the respective shifter fork is rotated to engage or disengage the respective sliding clutch member, each spring thus serving to yieldingly retain the respective sliding clutch member in engaged or disengaged position. p

The transfer mechanism, as shown, is so designed that its mechanism may be readily removed from the casing |04 for servicing or other purposes. The bearings |02 and |03 are bolted or otherwise removably fitted in the opposite sides of the casing, and by removing these bearings and their shafts, the latter are withdrawn from the ends of the shafts ||2 and IIB, thereby releasing these latter shafts for removal freely through the open top of the casing |04 While the cover |04a thereof is removed. As the sliding clutch members are splined removably on the inner ends of the shafts |00 and |0|, they alsoare readily removableefrom the open top of the casing. The axial thrust on the shaft ||2 from the bevel gear |22 is sustained by an antifriction thrust bearing which abuts at one side against the inner end of the respective bearing |03 and at its other end against a shoulder |50 onthe respective shaft |0I, and this shaft contains an anti-friction thrust bearing- |51 against which the adjacent end of the shaft ||2 abuts whereby the amal thrust from the.. beve1 gear |22 is ktransferred from the shaft ||2 to the respective shaft |0| and from the latter through the bearing |55 to the adjacent bearing |03. The axial thrust of the other bevel gear |23 is sustained by the inner end of the bearing I2I through an anti-friction thrust bearing |58 which is interposed between its inner end and the gear |23. Oil Seals |59 are provided for the shafts |00 and |0| whereby an oil bath may be maintained in the casing |04 and leakage therefrom prevented.

In some instances, it may be desirable to tie together the upper or free ends of the booms andA thus providexa rigid structure and the hoisting, towing, pulling orY hauling may be done conjointly by both booms, one 'of the booms being provided for such purposes with an apertured lear |60 projecting from a side thereof and the other boom with a socket IISI to receive said ear when the boomsY are brought together, a spring actuated locking pink |92 being carried by the socket and engageable in the aperture of the ear, substantially like the boom locking arrangement disclosed in my prior Patent Reissue No. 14,720, granted September 2, 1919.

The construction .and operation of the various elements of the apparatus having beendescribed in detail, the generaloperation of the 'complete apparatus is as follows: Normally, or whilelthe apparatus is in transit, both booms are preferably swung to the vrear of the truck and tied together by the locking of the servicev or boom cables from their' drums under the inuence of the load being prevented by the friction brakes 9d, 92 on the shafts of the worms which drive the service and boom cable drums 55 and 59.

The hoisting, towing, pulling, hauling or other operations may be performed either whilev the booms are tied together and sustain the load .conjointly, or such operations may be performed by either or both of the booms operating separately, as while one boom is being employed to hoist, pull, haul or otherwise operate upon a load sustained by one ofthe booms while swung to one side of the truck while the other boom is swung to the other side of the truck and itsserv- 'ice cable is attached to an anchor so that this service cable acts as a guy for the other boom whichsustains the load.

Assuming the booms have been arranged'ap- -propriately for the operation to be performed, the

power take-off from the transmission of the truck will ybe put into operation for lifting, the power shaft |28 being thereby driven continuously in the appropriate direction by power taken vfrom the usual engine of the truck. In order to lift one or the -other b-oom, the Bowden 4wire |33 or |34 is pulled, thereby shifting the respective sliding clutch member H or to couple the shaft l2 to the respective shaft liil, in consequenceof which the respective worm 8| will drive its cooperating worm wheel 'I8 in a direction to rotate the boom operating drum 59 in a direction towind the respective boom lifting cable 20 thereon, thus lifting the respective boom, and when ,such boom reaches the desired height, the clutch member which was engaged will -be disengaged from its companion clutch member by pushing the respective Bowden wire |33 or |34, thus stopping the boom lifting operation, and the boom will be held in its adjusted position by the irreversible action of the respective worm 8| and cooperating worm wheel 18; or when both booms are to be raised simultaneously, both clutch members l0 and are engaged at the same time.

y After the boom employed for hoisting, pulling, hauling or similar operation has been thus adjusted to the` desired height or angle, the apprpriate Bowden wire |3| or |32 is pulled, thereby shifting the respective, sliding clutch member |8 or |69 into engaged position and therebyl coupling the shaft 6 to the respective shaft |00, causing operation of such shaft Vto drive the respective worm 19 and thereby drive its cooperating worm wheel l1 in a direction to rotate the drum 55 to wind the service cable lli'thereon. Since the load to be lifted or pulled is attached .to the hook on the service cable, the load will pin- |B2,ounintentional unwinding f either or both booms and operate 'either' or both be lifted or lpulled until the respective clutch` `member |08 or |99 is disengaged from its companion clutch member by pushing the respective Bowden wire |3| or |32, whereupon the lifting or pulling vof the load will be stopped, and the load will be supported by the irreversible action of the respective worm -'|9 and worm wheel 11.

When both service cables are employed at the same time for hoisting, pulling or similar operations, both clutch members |08 and |09 are engaged at the same time by simultaneously pulling both Bowden wires l3| and |32.

In some instances, it may be desired tolift event, it is merely necessary to pullgthe appropriate ones or all of the Bowden wires,qall; oi the power for these operations being .provided bythesingle power shaft-IML e In order to lower one or the other boomorto lower the'service cable tov which the-load is attached, the power take-off from the triuck transmission is reversed or set tov drive vtheshaft'lZll yin the opposite direction to thatfor lifting, and

the sliding clutch member corresponding to the boom or service cable to be lowered' is engaged with its companion clutch member by pulling 'the respective Bowden wire, thereby causing power to be taken from the shaft v|20 to rotate thefrespective worm and cooperatin'g'worm v.wheel to rotate the corresponding boom' drum or vservice drum in a direction to unwind the respective boom or service cable, and, obviously, one or more or all of the boom and servicedrums may vbeadriven simultaneously, if desired the 'power therefor being supplied from the single. power `'shaft-'Hitt The torque reaction between the worm wheel T! or 'i8 and the casing 84 will be sustained -by the stops or adjustable screws 93 and Qlgwhich-abut against the ends of the respective casing 8d, although `y`when bothv worm wheels-'Ill and i8 `are driven simultaneously to raise the, 4resrnective boom and lift or pulla load on the. servicefcab-le for that boom, the torque reaction on thejcasing B4 from one worm will be neutralized more or less by the torque reaction from the othernworm wheel, it being noted that the worm wheels and 'I8 are driven in opposite directions to windthe cables on the

drums

55 and 59, res1:xectively.L

Also, as the axial thrusts'of the worms '19 and 8| are in oppositel directions during theirgoperation to raise the boom and lift the service. cable, the reactions of such aXialthrusts are distrib.- uted between the opposite vsides of ,the casing 83, thus enabling this casing to be constructed of r.el atively light weight,- and the torque/sustaining screws for thisy casing 'may also be lofrelatively light weight. As each casing-84 is mounted on the respective worm wheel shafts B3 and 15 and may each be removed asa unit therewith as hereinbefore described, these units and also the rear side of the frame in the region in;which.the drums 55 and 59v are located are readily made accessible. f

The large diameter service drums 55 employed not only enable a suiiicient length vof service cable to be wound thereon in a minimum numberof layers, thus avoiding wedging of the cable between the convolutions of the layerslwound on vthe-drum under tension of the load, butI also enable` drums length to be employed. Such narrow'drums'may be accommodated in a narrow frame 'which may be conveniently mounted transversely on a truck immediately behind the'cab, thus renderingr the rear side of the frame accessible for servicing of the mechanism therein andl leaving the rest' of the truck body available for loading or lother purposes, and the narrow service drums, as well as the boom operating drums 59, may be-'readily removed edge wise from the respective' en dsof the frame,l after removal of their shafts, vfor servicing or other purposes.

The employment vof wormsand worm wheels for driving the service and boom winding drums greatly simplifies the'apparatus since these worms and worm wheels are irreversible, thatv is, the worms will hold theworm wheels against retro,- graderotation under the loads imposed upon-the service and boom winding drums, 'and will automatically hold the load and the boom at anyheight to which the same are lifted, thereby obviating the necessity of employing complicated ratchets for locking the drums, and releasing and controlling means for unwinding the cables from the drums, as heretofore. Also, the present invention provides a novel transfer mechanism whereby the power for driving the drums to both wind and unwind the service and boom cables may be derived Vfrom a single power shaft which may .be driven conveniently by the usual engine of the truck on which the apparatus is mounted.

The present invention provides a heavy duty apparatus of great :power and strength for performing efcietly and rapidly a variety of operations, such as lifting, pulling, hauling or towing disabled automobiles -or other vehicles or apparatus, in vwhich all of the power required is supplied from a single source and may be controlled conveniently, as from the cab of a truck, and the various parts of the apparatus are readily acces- Y siblefor inspection, :removal or other servicing.

I claim as -my invention:

.1. 4Hoisting apparatus comprising a frame, a boommounted thereon, service and vboom operating .cables cooperative with the boom, drums for winding the respective cables, shafts mounted on the frame and connected to the respectivedrums for driving them, a worm wheel fixed to each of said shafts, a casing supported directly by said shafts independently of the frame, worms mounted in said casing and vcooperative with the respective worm wheels for operating them, and means on the frame and cooperative with said casing for sustaining the torque reaction of said worm wheels thereon.

2. Hoisting apparatus according to claim 1, wherein said torque reaction sustaining means comprises abutment members on the frame engaging opposite portions of said casing.

3. Hoisting apparatus according to claim 1, wherein said torque reaction sustaining means comprises a pair o'f alined screws mounted on the frame and adjustable into abutting relation with opposite portions of said casing. Y

4. Hoisting apparatus according to claim 1, wherein said worm wheels rotate in relatively opposite directions to operate the respective drums to 4wind the cables thereon.

5. Hoisting apparatus according to claim l, wherein said worms are mounted in parallel relation in said casing and rotate said worm wheels in relatively opposite Adirections to wind the respectivev cables thereon, and means for sustaining the thrust of said worms against the respective ends of said casing.

6. Hoisting apparatus comprising a pair of booms, service and boom operating cables for each boom, drums for winding the respective cables, gearings individual to said drums for the respective booms for operating them, a power shaft, and transfer mechanism interposed between said gearings and driven by said power shaft and comprising clutches for individually connecting the power shaft to the respective gearings for selectively operating the service and boom cable drums for both booms from said power shaft.

7. Hoisting apparatus according to claim 6, wherein said transfer mechanism comprises a pair of shafts, gearing connecting them to rotate in relativelyreverse directions, one of said shafts being connected to said power shaft to be driven thereby, clutch members on said pair of shafts,

12 companion clutchrmembers connected respectively to said gearings, and means individual to said clutch members and companion clutch members for engaging and disengaging them.

8. Hoisting apparatus according to claim 6, wherein said transfer mechanism includes means for each of said clutches for yieldingly holding the same in engaged and disengaged conditions.

9. Hoisting apparatus comprising a boom, service and boom operating cables cooperative therewith, drums for winding and unwinding the '-respective cab1es,'worm wheels disposed in different but adjacent planes land connected to the respective drums for operating them, a casing composed of similar halves enclosing the respective worm wheels, and a pair of worms journaled 'in the ends of the respective casing vhalves in acljacent parallel relatlon and engaging the respective worm wheels.

10. YHoisting apparatus comprising a frame, a pair of booms .mounted thereon, service and boom operating cables cooperative with the respective booms, drums mounted in the frame for winding and unwinding the cables, gearing including worm wheels connected to the drums for each boom and a pair of worms meshing respectively With the worm Wheels for the respective boom, transfer mechanism comprising a casing, a power shaft journaled therein, a pair of driving shafts connected to the power shaft and provided with clutch members, pairs of driven shafts journaled in the opposite sides of the casing in alinement with and supporting the respective driving shafts and having sliding clutch members on their inner ends to cooperate with the .respective clutch members on said driven shafts,

Yand having `parallel upright columns providing openings vat 'the opposite ends of the frame and at the respective sides of the truck, booms swiveled on the frame adjacent to its opposite ends, service and boom operating cables cooperative with each boom and extending into the respective ends of the frame, 'drums for winding said cables movable edgewise into and out of operative positions between the columns through said openings at the respective ends vof the frame, and shafts mounted in the frame for removably supporting the drums therein for rotation in a common plane. I

12. Wrecking apparatus for mounting on a truck transversely and behind the cab thereof, comprising a 'relatively narrow frame having drums 'mounted in a common plane in each end thereof at the respective side of the truck for winding a servi-ce cable and a boom operating cable, a boom swiveled on a vertical axis adjacent to each end of the frame and cooperative with said service and boom operating cables, sets of gearings at a side of the frame and'adjacent to the respective ends thereof for operating the drums for the service cable and boom operating cable for the respective booms, and transfer mechanism mounted at said side of the frame midway between its ends and between said sets of gea-rings and connected to Said sets of gearings for operating them.

13. In hoisting apparatus, 'a boom, a sheave for a service cable swiveled in the end of the boom for rotation about the longitudinal axis of the boom as a center, a boom operating cable, a supporting sheave having a shaft connected to the boom operating cable, and a sling having its ends connected to the outer` end of the boom at opposite sides of said sheave, and having a portion thereof between its ends extending around said supporting sheave connected to the boom operating cable.

14. In hoisting apparatus, a boom having a sheave mounting swiveled in the end thereof for rotation about the longitudinal axis of the boom as acenter, a service cable sheave supported by said mounting for rotation on a substantially horizontal axis, a boom supporting cable, a pair of supporting sheaves having a shaft connected to said cable, and a sling having its ends looped and engaging the sheave mounting at opposite sides of the service cable sheave, and having its intermediate portions extended around said pair of supporting sheaves.

15. Hoisting apparatus comprising a boom, service and boom operating cables cooperative therewith, drums for winding the respective cables, worm and worm wheels connected to the respective drums for rotating them to wind and unwind the respective cables, power means for operating the worms, and a friction brake cooperative with each worm for holding it against rotation independently of the power means, said friction brake comprising inner and outer conical members, one of which is fixed to turn with the respective Worm, and means including a pin cooperative with the other conical member to permit axial movement but prevent rotation thereof.

16. Hoisting apparatus comprising a narrow elongated frame, a pair of booms mounted respectively on the ends thereof, service and booml operating cables for each boom, drums mounted in the respective ends of the frame for Winding the respective cables, gearings adjacent to the respective ends of the frame and individual to said drums for operating them, a power shaft mounted between the ends of the frame, and transfer mechanism mounted adjacent to and driven by said power shaft and comprising clutches for individually connecting the power shaft to the respective gearings, and means connected to said clutches for controlling them from a remote point.

17. Hoisting apparatus comprising a frame, a boom pivotally mounted thereon, a service cable carried by the boom, a boom supporting cable connected to the boom, a pair of drums mounted in said frame adjacent to the pivotal mounting of the boom for winding the respective cables, a casing adjacent to the pivotal mounting of the boom, a pair of worm wheels mounted in the casing and connected respectively to said drums, a pair of worms mounted in the casing and cooperating respectively with the worm wheels, a power shaft, means operable by the power shaft 14 for rotating said worms in relatively opposite directions to operate the drums to wind the respective cables, and clutches between the power shaft and said Worms for selectively connecting the latter to the power shaft.

18. Hoisting apparatus comprising a frame, a boom pivotally mounted thereon, a service cable carried by the boom, a boom supporting cable connected to the boom, a pair of drums mounted in the frame adjacent to the pivotal mounting of the boom for winding the respective cables, a casing adjacent to the pivotal mounting of the boom, a pair of worm wheels mounted in the casing in overlapping relation and in adjacently located planes, a gear connected to one of the worm wheels and cooperative'with one of the drums, a shaft connected to the other of said worm wheels and connected directly to the other drum, said gear and shaft rotating the drums in the same cable winding direction by rotation of the worm wheels in relatively opposite directions, a pair of worms mounted in said casing and meshing with the respective worm wheels, a power shaft, and worm driving shafts having means for connecting them to the power shaft to rotate the worm wheels in relatively opposite directions to wind the cables on the respective drums.

19. Hoisting apparatus comprising a frame, a pair of booms pivotally mounted at opposite ends thereof, service cables carried respectively by the booms, boom lifting cables for the respective booms, service and boom cable operating drums mounted in the respective ends of the frame adjacent to the pivotal mountings of the respective booms thereon, a pair of gearings at a side and adjacent to the respective ends of the frame and connected to the respective adjacent drums for operating the drums, a power shaft mounted intermediately between the ends of the frame, pairs of shafts extending longitudinally at said side of the frame, means for connecting the shafts of each pair respectively to the gearings for operating the service and boom cable drums adjacent to the respective ends of the frame, and means including clutches for selectively connecting the shafts of said pairs to the power shaft.

20. Hoisting apparatus comprising a boom, service and boom operating cables cooperative therewith, drums for winding the respective cables, worm wheels disposed in different but adjacent planes and connected to the respective drums for rotating them to wind and unwind the respective cables, worms mounted on adjacent parallel axes and cooperating with the respective worm wheels, power means for operating the worms, clutches for connecting and disconnecting the worms and power means, and friction brakes constantly acting on the respective Worms to resist rotation thereof and thereby hold them against rotation under the influence of the respective worm wheels while the worms are disconnected from the power means.

ERNEST W. HOLMES.