US2966338A - Hoisting apparatus - Google Patents

Description

Dec. 27, 1960 H. s1MoNs i 2,966,338

HOISTING APPARATUS Filed May 5, 1956 5 Sheets-Sheet 1 Harold S'imns MMM A ttorney Dec. 27, 1960' H. SIMONS HOISTING APPARATUS 3 Sheets-Sheet 2 Filed may s, 1956 nvenfor Harold Simons Attorney Dec. 27, 1960 H. slMoNs HOISTING APPARATUS Filed May 3, 1956 3 Sheets-Sheet 3 Inventor Harald" Simons Harney United States Patent HOISTING APPARATUS Harold Simons, 21 Cranham Road, Woodhouse Park, Manchester, England Filed May 3, 1956, Ser. No. 582,626

2 Claims. (Cl. 254-150) This invention relates to hoisting apparatus of the type in which the load is lifted through the medium of a cable adapted to be wound upon a drum by manual or other power.

In such apparatus, especially When hand-operated, it is known practice for reverse rotation of the drum under load to be resisted by a brake which cornes into action automatically as soon as the winding torque is relaxed, and sometimes a governor is provided to control the rate of unwnding of the cable on manual release of such brake.

It is frequently necessary, of course, to pay out the cable n unloaded condition prior to connection thereof to the load, and hitherto, unless the cable has carried a hook or other load-suspension device heavy enough to draw the wound cable off the drum, such paying-out has necessitated pulling manually upon the free part of the cable, any attempt at positive rotation of the drum in the unwinding direction merely loosening the turns of cable thereon and causing them to tangle or jam, especially when the drum is wholly or partly enclosed.

The use of a heavy hook or its equivalent as aforesaid may, however, be rendered impracticable by reason of the fact that the cable needs to be led through a restricted opening, such circumstances arising, for example, when the load requires to be raised to the underside of an aircraft wing in which it is undersirable to provide an opening of more than (say) 1 inch diameter.

The object of the present invention is to provide, for use in cases such as that above cited, and otherwise, an improved construction of hoisting apparatus in which the cable is positively discharged from the drum on reverse rotation of the latter.

According to the invention, hoisting apparatus of the type referred to is characterised in that a concentric shroud rotating with the winding drum provides just sufcient radial clearance around the latter to permit the accommodation of a single layer of cable turns thereon, said drum being provided with an anchorage to which said cable is led through a duct at one end of said shroud and being moved endwise automatically and positively during rotation so that, for each revolution thereof in the unwinding direction, the cable anchorage is advanced towards said duct an axial distance corresponding to the diameter of the cable used.

The duct aforesaid may be formed tangentially of a circumferential rebate or scroll in a non-rotary ring which receives the outermost cable turn, and preferably the automatic traversing of the drum is effected through the medium is eiected through the medium of a non-rotary leadscrew and a nut thereon whereby the drum is slidably connected to a concentric driving member.

In the accompanying drawings:

Fig. 1 is a part-sectional side elevation of one form of the improved hoisting apparatus;

Figs. 2 and 3 are sections on the lines 2 2 and 3-3, respectively, of Fig. 1;

Fig. 4 is a sectional side elevation of a preferred form 2,966,338 Patented Dec. 27, 1960 of load-suspension device for use with the apparatus aforesaid.

Fig. 5 is a schematic sectional side elevation showing an alternative method of driving the winding drum illustrated in Fig. 1.

Fig. 6 is a part-sectional side elevationof a preferred form of crank handle for use with the hoisting apparatus, and

Fig. 7 is an end view of the crank handle, as seen from the left-hand side of Fig. 6.

In the construction illustrated in Figs. 1 to 3, the hoisting apparatus is enclosed within a casing 10 formed of aluminium or light alloy castings and having at one side a drum-shaped extension 11.

A cover plate 12 closing the outer end of this extension 11 serves to retain a ball-bearing 13 in alignment with a similar bearing 14 in the adjacent sidewall of the casing 10, and in these two bearings is journalled a hollow shaft 15.

A winding drum 16 having a plain cylindrical surface is slidably mounted upon this shaft, within which is a coaxial lead-screw 17 fixed to the cover plate 12. A nut 18 engaged by the lead-screw is formed with diametrically-opposed trunnions 19 whose inner parts fit longitudinal slots 20 in the shaft 15 and whose outer ends are retained (by means of a ring 21 and snap-ring 22) in radial slots 23 in the adjacent end of the drum 16. In this way the latter is angularly located with reference to the shaft 15, whilst being movable longitudinally thereof under the control of the nut 18 when the shaft is rotated as hereinafter described.

` At the end of the drum 16 remote from the nut 18 is a circumferential flange 24 whose depth is slightly greater than the diameter of the cable 25 to be wound on such drum.

Adjacent this flange the drum has a tangentially-disposed hole 26 which snugly accommodates a nipple 27 fixed to the cable end and is intersected by a second hole 28 drilled parallel to the drurn axis, this hole 28 containing a plug 29 forked to embrace the cable 25 behind the nipple 27 and providing an anchorage for the latter. A screw 30 held captive by a ring 31 and snapring 32 passes through a coaxial extension of the hole 28 and engages a tapped bore 33 in the plug 29. The latter is angularly located by reson of a flat 34 thereon engaging a pin 35 inserted radially into the drum 16, so that, after entry of the nipple 27 in the hole 26, the plug 29 can be advanced into locking engagement therewith by operation of the screw 30.

It will be assumed that, after the nipple 27 has been anchored as aforesaid, a suitable length of the cable 25 is wound helically upon the drum 16 in a single layer of juxtaposed turns, which latter are closely embraced by a cylindrical sheet-metal shroud 36 fitting around the drum flange 24 and fixed at one end to a disc 37 keyed to the shaft 15 within the main part of the casing 10.

The parts are so designed that, when the slidably mounted drum 16 is at the inner end of its permitted travel (i.e. in contact with or adjacent the disc 37), the whole of the wound cable 25 is confined by the sheetmetal shroud 36 and the outermost turn thereof is snugly engaged within a circumferential rebate 38 in a Phosphor bronze abutment ring 39 fixed within the casing extension 11. Preferably this rebate is of progressively-increasing depth in one angular direction, so that it forms a scroll conforming to the helical arrangement of the cable turns upon the drum 16.

A tangential groove leads from the rebate 38 to the the cable 25 fits snugly and which is directed axially of 3 a circular mouthpiece 41 formed on the casing extension 11.

This mouthpiece contains a further cable guide in the form of a longitudinally-grooved plug 42 contained in a shouldered bushing 43, both of these parts being pinned in position at 44.

Bolted at 45 between lugs 46 at opposite sides of the mouthpiece 41 is a socket member 47 adapted for spigotal engagement with a tubular column 48 and slotted to receive a radial stud 49 on the latter, a handnut 50 applied to this stud cci-operating with a seating 51 at the exterior of the socket 47 to secure the column 48 in a readily detachable manner.

Mounted concentrically within the column 48 is an inner tube 52 forming a guide for the cable 25. A block 96 is provided near the upper end of socket member 47 to assist in guiding cable 25.

It will be appreciated-that, when the drum 16 and shroud 36 are rotated by the shaft 15 in a direction to unwind the cable 2-5, the drum 16 is automatically traversed, through the medium of the lead-screw 17 and nut 18, so that the flange 24 thereon approaches the rebated ring 39.

The pitch of the lead-screw 17 is made exactly equal to that of the cable turns upon the drum 16, with the result that, for each revolution of the latter, a complete turn of cable is unwound therefrom and fed positively through the tangential duct 40 and guide 412, the rest of the cable remaining closely confined by the shroud 36 through which the drum 16 is progressively advanced.

The outward limit of the drums travel is defined by a screw 53 in its outer face engaging the end of the cas ing extension 11, and it will be appreciated that the cable 25 may be Arewound in normal manner, the guiding means above described ensuring that the cable turns are laid evenly and closely around the drum 16.

The guide tube 41 is of large enough diameter to permit the passage therethrough of a second nipple 272 at the free end of the cable 25, this outer nipple being detachably secured to some form of loadsuspension means.

In the case of a hoisting apparatus whose cable 25 requires to be fed through an opening 54 in (say) an aircraft wing which is too small to admit a hook the nipple 272 may be detachably engaged with a spherical or part-spherical end fitting of appropriate size.

One example of such a fitting is shown in Fig. 4 and comprises a spherical body 5 with a cylindrical shank 56 grooved circumferentially to receive a gapped spring ring 57, the fitting having a radial slot 58 which is counterbored at its outer end to receive the nipple 272 after the cable 25 has been laid in the slot 58 and its escape prevented by rotation of the ring 57.

The end fitting above-described is intended for detachable engagement with a suspension hook as a suitable formation on the article to be lifted, after passage through the restricted opening 54.

For operating the hoisting apparatus, manual torque is applied to the projecting end of a shaft 59 journalled in ball-races 60 at opposite sides of the casing 16 and disposed parallel to the axis of the drum shaft 15, being connected to the latter by suitable reduction gearing.

In the convenient arrangement, shown, a small sprocket 61 integral with the shaft 59 is engaged by a roller chain 62 which also passes around a larger sprocket 63 fixed to the end disc 37 on the shaft 15.

To enable a still more powerful torque to be applied to the drum 16, a second winding shaft 64, also parallel to the axis of the shaft but closer thereto than the shaft 59, is connected to the latter through the medium of a roller chain 65 engaging a large sprocket 66 fixed to the shaft S9 and a small sprocket 67 fixed to the shaft 64, which is jourualled in ball-races 68 in the casing 10 with one end projecting therefrom.

For rapid paying-out 0f the cable 25, the manual torque aforesaid will normally be applied to the shaft S9,

and during this operation it is important when dealing with a stranded wire cable, to avoid any axial compressive stress thereon such as may result from the free movement of the end nipple 272 being obstructed in some way.

With this in mind, the column socket member 47 is provided at opposite sides with slots 69 through either of which the cable 25, if compressed, can loop outwards in the event of the nipple 2.72 failing to run freely through the guide tube 52 or elsewhere, the escaping bight of cable being readily visible to the operator.

Having cleared the obstruction, the operator winds in the bight aforesaid prior to resuming the paying-out operation, and to ensure that any twist which may develop in such bight will not cause the cable 25 to jam in the adjacent slot 69, each of such slots is normally closed by the inturned extremities of two double-ended spring blades 70 which are secured to the exterior of the socket member 47 at opposed positions. It will be appreciated that the juxtaposed spring ends separate readily to permit escape of the cable bight as aforesaid, but offer sufficient resistance to its return movement to remove any twist therefrom.

I Operatively connected with the low-speed winding shaft 64 as hereinafter described is a brake-drum 71 embraced by a friction-lined band 72 which normally grips it so as to prevent rotation of such shaft (and hence of the drum 16), a load raised by the cable 25 being thereby automatically sustained on relaxation of the winding torque.

As shown in Fig. 2, one end of the band 72 has an adjustable anchorage to the casing 10 at 73 whilst the other end is attached to a block 74 on a release lever 75 pivoted at 76 and provided with a thumb-piece 77 at its outer end. This thumb-piece is disposed externally of the casing 10 and guided for sliding movement in suitable proximity to a hand-grip 78 whereby the apparatus may be supported.

When it is desired to lower the load, the thumb-piece 77 is pressed inwards against a compression spring 79, thereby slackening the band 72 and allowing the brakedrum 71 to rotate.

A free-wheel mechanism interposed between the brakedrum 7|1 and the shaft 64 allows the latter (and equally the shaft 59) to be rotated freely in the Winding direction, but causes each of such shafts to be checked by the band 72 immediately when the winding torque is relaxed, the descent of the load being thereafter controlled by means of the thumb-piece 77 aforesaid.

In the convenient arrangement shown in Figs. 1 and 2, an enlarged portion 64a of the shaft 64 is formed with four radial sockets 80 each containing a spring 81 and slidable pawl 82 adapted to co-operate with ratchet teeth at the inner periphery of an annular plate 84 fixed concentrically to one end of the brake-drum 71 which is freely mounted upon the shaft 64 through the medium of ball-races 85.

Each pawl 82 preferably consists of a round pin with a diametral slot 86 milled across its outer end at a suita-ble angle, the sides of such slot engaging those of the annulus 84 so that the pin is angularly located.

To control the rate at which the load descends when ,the brake is released, there is provided a governor comprising a disc 87 freely rotatable (through the medium of ball-races 88) upon the shaft 59, and a plurality of sector-shaped blocks 89 disposed between pegs 90 which project from one face of such disc at angularly-spaced positions.

The disc 87 has Vfixed to the opposite side thereof a small sprocket 91 co-operating with a roller chain 92 which also engages sprocket teeth 93 provided around the outer periphery of the annular plate 84.

When the cable 25 is being drawn ot the drum, the governor disc 87 and associated blocks 89' are rotated at a relatively high speed through the medium of the three chain drives 62, 65, 92, so that the centrifugal force acting upon the blocks 89, coupled with the radial components of the forces exerted upon the inclined faces thereof by the driving pegs 90, causes friction facings 94 on such blocks to be pressed against a cylindrical surface 95 provided within the casing 10 in concentricity with the disc 87.

It will be appreciated that the arrangements above described are capable of modification in various ways within the scope of the invention.

For example, various components such as one wall of the casing 10, the outer end of the extension 11, the drum-shaft disc 37, and the abutment ring 39, may be formed as sheet-metal pressings instead of being cast.

Furthermore, the governor disc 87 and brake-drum 71 may be made integral with one another or otherwise coaxially united, and the brake release lever 75 may have a separate actuating member, in which case it is convenient to employ a two-armed lever with both ends of the band 72 anchored to the arm adjacent the actuating member and the other arm acted on by a spring.

Fig. shows an alternative means for preventing compressive stresses being set up in the cable 25, more particularly for use in heavy-duty apparatus where the cable is too stili to escape through a slot such as that shown at 69 in Fig. 2.

It will be seen that the outer face of the drum-shaft end disc 37 is formed with radial slots 97 containing square-section pawls 98 which are retained by a ring 99 and urged outwardly by springs 100 into engagement with ratchet teeth 101 at the inner periphery of the associated sprocket 63, the arrangement being such as to provide a solid drive in the winding direction Whilst permitting the sprocket 63 to slip relatively to the drum shaft should the positive payingout of the cable 25 be obstructed.

For applying manual torque to either of the winding shafts 59, 64, the form of crank-handle illustrated in Figs. 6 and 7 is preferred, inasmuch as it is designed to slip relatively to the shaft at a predetermined torque and so prevent accidental overloading of the cable 25 or other parts of the apparatus. It has the additional merit that, although automatically operative when grasped by the operator, it has no driving connection with the associated shaft at other times and can thus be left permanently in position without risk of its striking the operator should the shaft rotate rapidly following release of the brake.

As will be seen from Fig. 1, the projecting end of each winding shaft is squared at 102 to receive a dog member 103 which is held in place by a coaxial set-screw 104 in washer 105, two faces of the squared extremity being milled longer than the others so as to leave diametrically-opposed teeth 106 which enter recesses 107 in the inner end of the member 103.

The handle crank 108 is hinged at 109 upon a radial lug 110 on a separate hub member 111 which is adapted to embrace, and to rotate freely upon, the cylindrical exterior of the dog member 103. The member 111 is detachably positioned upon the latter by means of a spring-pressed ball 112 or other detent which enters a circumferential groove 113 in the member 103 when the member 111 has been slid thereon up to a stop shoulder 114.

The hinged crank 108 extends across the outer end of the hub member 111 and is formed, directly opposite the latter, with a hollow boss 115 containing a plunger 116 provided with a cross-pin 117 and held captive by a screw 118 which is coaxially slidable in the boss 115.

Slidably mounted upon the plunger 116 is an annular clutch plate 119 which is pressed against the cross-pin 117 by means of a strong coil spring 120, the other end of the latter engaging a washer 121 with a set-screw 122 which co-operates with the outer end of the boss 115 for adjustment of the spring pressure.

The clutch pllate 119 is notched at its periphery to engage locating pegs 123 carried by the crank 108 and also has a diametral V groove 124 for receiving the crosspin 117.

A spring 125 acting between the hub lug 110 and crank 108 normally holds the latter with the cross-pin 117 clear of the dog member 103, but the natural effect of the handle 126 being grasped by the operator is to move the hinged crank 108 inwards so that the cross-pin 117 enters a diametral slot 127 in the member 103.

Thus, on the crank 108 being rotated, a drive is transmitted therefrom to the dog member 103 and associated winding shaft by way of the pegs 123 and the grooved clutch plate 119 located thereby.

In the event of an overload being encountered, however, the adjustable spring yields to permit the clutch plate groove 124 to ride past the cross-pin 117, and thereafter the crank 108 and hub member 111 are rotated without alecting the dog member 103.

I claim:

1. In a hoisting apparatus comprising a casing, a shaft journaled in said casing, a drum Slidably mounted on said shaft, means for rotating said shaft, a single layer of cable on the face of said drum, a shroud covering said layer to conne the same, a duct in said casing through which said cable is adapted to be led, means rotated by said shaft and connected to said drum for moving said drum longitudinally of said shaft at such a rate that for each revolution of said shaft the drum advances a distance approximately equal to the diameter of the cable, the improvement which comprises a guide tube for said cable attached to a socket member, said member being attached to said casing and an aperture in said guide casing to permit the escape of a bight of said cable.

2. An apparatus according to claim l wherein coacting spring blades close said aperture, said blades being yieldable to permit said escape and which remove twist from said bight during rewinding of said cable.

References Cited in the le of this patent UNITED STATES PATENTS 652,893 Herdrnan July 3, 1900 1,118,270 Dahl Nov. 24, 1914 1,706,109 Dodge Mar. 19, 1929 2,257,476 Morgan Sept. 30, 1941 2,284,532 Napier May 26, 1942 2,327,163 Barrett Aug. 17, 1943 2,495,804 Berchtold Jan. 31, 1950 2,630,299 Troche et al Mar. 3, 1953 2,726,755 Moser Dec. 13, 1955 2,783,025 Scheidt 1 Feb. 26, 1957 2,868,504 Minty Jan. 13, 1959

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