US1555094A

US1555094A - Hoist

Info

Publication number: US1555094A
Application number: US646511A
Authority: US
Inventors: Thomas E Adams
Original assignee: Individual
Current assignee: Individual
Priority date: 1923-06-20
Filing date: 1923-06-20
Publication date: 1925-09-29
Anticipated expiration: 1942-09-29

Description

Sept. 29, 1925. 1,555,094

, T. E. ADAMS HOIST Filed June 2 1923 4vsheets sheet 1 Sept. 29, 1925.

T. E. ADAMS HOIST \Filed June 20. 25 4 Sheets-Sheet 2 Sept. 29, 1925. 1,555,094

T. E. ADAMS HOIST Filed June 20, 1923 4 Sheets-Sheet S I ii km a 4a Sept. 29, 1925. 1,555,094

'r. E. ADAMS HOIST Filed June 20, 1923 4 Sheets-Sheet 4 film M MM Patented Sept. 29,, 1925.1

UNITED v STATES THOMAS E. ADAMS, or CLEVELAND, 01110.

HOI-ST.

Application filed June 20, 1923. Serial No. 646,511.

To all whom it may concern. I Be it known that I, ,THoMAs E. ADAMS,

a citizen of the United States, residing at.

Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Hoists, of which the following is a full,-clear, and exact description, reference being had to the accompanying drawings.

My invention relates to hoisting machinery, and in particular to a portable electric hoist,-. although certain of its features are of more general application as will hereinafter appear. I

In fact, the fundamental thought which constitutes the essence of my invention and.

the nucleus of the improvements and de-.

velopments herein disclosed; is that of provlding an. internal worm gear and a worm cooperating therewith the arms of wh1ch is in substantially the central plane of "the wheel; and the wide range of utility of an arrangement of this kind is self-evident. As to this basic thought, the objects in view are to greatly increase the efficiency and holding power of worm gearing; to render the same more compact; to improve the lubricating facilities of such gearing; and to provide an arrangement which adapts itself more readily to certain circumstances, and to a greater number of uses, than prior forms of worm gearing.

That the nature of my invention as it pertains to improvements in portable hoists may be better understood and its advantages more fully appreciated, brief reference may be made to prevailing types of portable hoists by way of comparison. For example, one object of m invention is compactness, and another is lightness, where as little has heretofore been accomplished in these direc tion s-in the designing of hoists of the class to which my invention particularly relates. Another object is to provide a hoist that will sustain any load within the range of its lifting capacity with absolute certainty without the aid of a brake. In the case of my improved hoist a brake is employed only for the purpose of obtaining accuracy in the stopping of a load in suspension. 1

Another object of my invention is to pro vide a unique gear arrangement characterized by two sets of worm gears in series which effects the highly desirable gear reduction and increased power without the objectionable number of gears usually employed in the attainment of these ends. This feature contributes to the compactness and lightness of the structure and is responsible for the positiveness with which the hoist sustains its load. As will be gathered from this, this gear arrangement is especially suitable for the purpose at hand, although its adaptability to other uses will be apparent.

Further objects of the invention are to provide a hoist of the aforesaid character that is very powerful for one of its size and weight, and is substantial and durable; to provide a portable hoist that may be readily handled by one man in that by engaging the liftingcable to a support in the vicinity of the one from which it is desired to sus pend the hoist, the hoist may beoperated to cause it to climb the cable so that all the operator need do after it has attained the desired elevation is to engage its suspension hook with the trolley or other support from which the hoist is to be hung; to provide for various cable and pulley arrangements whereby the hoist may be caused to lift light loads quickly and heavier loads more slowly with a proportional increase of power; to provide an electric hoist that will safely hold its maximum load whenever the electric power ceases; to provide means for stopping the hoistautomatically when the load has reached a given elevation thereby to prevent damage should the operator through any cause fail to shut off the power; and to provide an electric hoist wherein, by the use of a single element or cable, the operator may start, stop or reverse the motor, or apply the brake for effecting an accurate stop.

The foregoing objects, with others hereinafter appearing, are attained in the embodiments of the invention illustrated in the accompanying drawings wherein Fig. 1 is a sideelevation of my improved portable electric hoist with a part of the casing broken away to reveal eertain structural features; Fig. 2 is a perspective view of the control element or cable; Fig. 3 shows, more or less diagrammatically, the manner of elevating the hoist to position for use; Fig. 4 is a central vertical section through the hoist at right angles to the plane of Fig. 1 and on a .scale considerably enlarged over that of Fig.

1; Fig. 5' is an enlarged sectional detail of the combined "worm and worm wheel and its mounting; Fig. 6 is a sectional detail,

substantially on the line'66 of Fig. 4,

' stator 3 is supported in a plane transverse theinclined axis of the casing, and the edges of the casing sections come together about the stator. The primary winding 4 is suitablyengaged within slots or grooves of the stator, while the secondary winding, so-

called, is made up of conductor rods 5 which extend through the laminations of the rotor 6 and are connected at their ends to the end rings 7 and 8. The latte'r ring 8 (Fig.

4) insteadof being flat, as usual,-1s cylindrical .so as to serve as a brake drum, as will presently appear. From this brief description of the rotor it will be recognized as one of the well known squirrel-cage type. While on this point it may be explained that end ring 7 might also be made cylindrical and have associated with it a magnetic brake which, according to common practice, is automatically set by a spring.

when the current to the motor is'shut oil, and maintained in indl'ec'tive condition as long as the current flows; it being remembered that in brakes of this character the windings of the brake mechanism and motor are in series. Illustration of this is deemed unnecessary as it would require only the changing of ring 7 to a form substantially like that of ring'8 and the supplying of the well known magnetic brake mechanism.

The rotor is clamped between flanges 10 and 11 upon the motor .shaft 12, the flan 10 engaging an abutment 13 on the sha t, while a nut 14, thatis applied to a threaded portion of the shaft, engages the flange 10.

The respective upper and lower ends of the shaft 12 are journaled within'suitable antifriction bearings 16 and 17 which are contained within cavities formed in the casing sections, the cavity which housesthe hearing 16 being closed-by a cap 18 containing a washer 19 of suitable packing material so that lubricant supplied to the bearing 16 will not find its wayto the electrical elements of the motor.

A suitable distance below the stator, the casing is divided by a partition 25 having acentral aperture through which the lower end of the motor shaft extends, and the partition incorporates a housing 26 within which an anti-friction bearing 27 is con tained which serves to support the motor shaft intermediate its ends. In a reduced annular portion of the housing 26 is contained a washer 28 of packing material which prevents lubricant, present in the compartment below the partition 25, from passingfrom the under to the over side of the partition should -the hoist be inverted during handling. 7 P

A worth 30 is secured to the lower end of the motor shaft and meshes with a worm gear 31 that is formed about the waist or. equator of what I shall term a. combined worm and worm gear 32, the end portions whereof are provided with threads. This combined worm and worm gear isgin effect, a worm having the central portion of its thread interrupted, the lead of the threads at the two ends being one and the same, and therefore, in efiect, continuous.

A hoisting drum 35, shown as provided with the usual cable groove, surrounds the motor casing and is supported therefrom through ball bearings 37 which operate between inner and outer races 38 and 39, respectively, the former being fitted to annular shoulders 40 of the motor casing, and the latter having their peripheral portions threaded and screwed into the internally threaded edge portions of the drum 35. Near their inner edges, and on their inner sides, the ball races 39 are grooved to receive expanding spring rings 41 which constitute abutments for the inner edges of the inner ball races. 7 Preferably the ball races are stamped from sheet metal of suitable gauge and quality, such a method of production insuring accuracy and uniformity,

as well as cheapness. Rings 42, of suitable packing material, are interposed between the inner edge portions of the outer ball races and the adjacent portions of the motor casing for the purpose ofexcluding dust from, and retaining lubricant within, the casing.

An internal worm gear 45 extends about the interior of the drum 35 and is preferably --formed integral therewith, and the teeth of said worm gear mesh with the threaded portions 32 of the combined worm and worm gear 31. The lower casing section 2 is provided with brackets 46 (Figs.

1 and 5) which overhang theworm gear 45 and support a? stub shaft 47 whereon the combined worm and worm gear 31 is mounted through. anti-friction bearings 48. Suitable means,.such as a cotter pin 49, extending through registering holes in one of the brackets 46 and the shaft 47 and serves to retain the shaft against longitudinal displacement.

Frames 50 are disposed on opposite sides of the motor casing and are secured thereto by bolts 51 and 52 which passthrough the casing and through portions of said frames. The frames are further secured to the motor casing by bolts 53 which assist in securing the sections 1 and 2 of the motor casing together. To lugs 55 of the frames 50 are pivotally connected the ends of a yoke 56 which has swiveled to it the suspension hook 57 by .means of which the hoist is hung from a suitable sustaining structure. A loop 60 is Obviously, in lieu of the cable arrangement just described, a second sheave block may be hung from the loop 60, and the cable 64 en gaged over it and the hook 63 suitably connected to the sheave block 67, thus decreasing the speed with which the load would be lifted when the motor is running at a given speed, while proportionately increasing the power. Or, a double sheave block could be substituted for the sheave block 67 and a single sheave block suspended from the loop 60, with an appropriate arrangement of the 'cable 64, which would further increase the lifting power of the hoist. Thus, by using multiple sheave blocks, the power may be in creased to whatever is desired. The obviousness of these arrangements make specific illustration unnecessary.

An expanding non-magnetic brake shoe 70 (Fig. 6) is located within the end ring 80 which, as previously stated, constitutes a brake drum. To the inner side of the central portion of the shoe is attached a bifurcated fitting- 71 which embraces a stub 72 that is secured to and rises from the partition 25 (Fig. 4). A spring 73, which has its ends connected, through fittings 74, with the ends o the brake shoe, tends to contract the shoe and engage opposed abutments 75, shown as formed integral with the fittings 74. with the. opposite sides of a cam 76 that is mounted upon a stud 77. An arm 78, which is fixed with respect to the cam 76, has its free end pivotally connected to one end of a link 79, the other end of the link being simi larly connected at 80 to a lever 81 that is pivoted at 82 to the motor casing. A spring 85 tends to maintain the lever normally in close proximity with the casing. The free end" f the lever 81 is shown as provided with; an eye 86 for the connection, as through a snap 87, of a brake control element or cable 88.

lVithin a hollow boss 90 that is formed in one side of the upper section 1 of the motor casing are supported contact posts 91, which h ve connection, through the leads'92, with certain sections of the primary winding 4,

in accordance with usual construction of three-phase induction motors. The posts 91 are preferably supportedupon and insulated from a substantial stool 94, the legs 95 whereof extend out over the adjacent portion of the winding 4 and are secured to the stator 3. A plug 96 is designed to fit within the boss 90 and contains sockets 97 for the reception of the contact posts 91.

The plug 96 may be fitted into the boss 90 in either of two positions which are 90 apart. \Vhen the plug 96 occupies one of its two angular positions within the boss 90, connections are established which will cause the motor to run in a given direction; but when the plug is inserted into the boss 90 in v its other position it will establish connections causing the motor to run in a reverse direction. This will be readily understood by those familiar with the type of motor in question, and the arrangement of contacts is a matter of electrical expediency.

In Fig. 3 I have shown more or less diagrammatically a track 100 on which a trolley 101 is mounted. The trolley may be shifted to any position along the track, but at all times maintains electrical contact, through shoes or brushes shown conventionally at 102, with electrical conductors 103. A connection similar to that just decribed as comprised, generally, of the posts 91 and sockets 97 occurs at 104 on the trolley 101. 105 indicates a cord or cable containing electric wires or conductors through which electrical connection is made between the trolley and the motor.

This cord or cable terminates at one end in branches 106 and 107 (Fig. 2) the former having connection with the block 96, and the latter with a block 108 which constitutes a part of the previously mentioned connection 104 of the trolley 101. The opposite end of the cord or cable 105 has branches 110 and 111 which carry. respectively, a socket member 112 and a plug member 113, of a separable switch. For convenience and the avoidance of confusion when operating the hoist, the brake control cord or cable 88 may be incorporated in the cord or cable 105.

When the hoist is suspended from the trolley 101 and is in readiness for use, the plug 108 is inserted in the trolley connection 104 and the plug 96 inserted in the boss 90 of the motor casing. Now, when it is desired to lift a load, thelifting hook or grapple is engaged with the load and the plug member 113 is inserted within the socket member 112 of the separable switch with the

indications

112 and 113 of the

respective members

112 and 113 opposite each other. Current will be directed through the motor to cause it torotate the drum in a direction to lift the load. As soon as the

switch members

112 and 113 are separated, the load will be stopped. To prevent moverse to that wherein the

indications

112 and 113 are in register.

To guard against damage which would occur should the operator through carelessness or other cause fail to open the switch when hoisting a load, I provide the following mechanism: 115 is a stub shaft jour, naled within a boss 116 that is formed on the motor casing, and to one end of the shaft is secured a lifter 117 while an arm 118 is fastened to the other end thereof. The free end of the arm 118 is so disposed to the edge of the drum 35 as to be engaged and depressed by the cable 64 when the latter arrives at the adjacent edge of the drum. The free end of the lifter 117 normally reposes beneath one end of an elongated head 120 wherewith the plug 96 is equipped, the opposite end of said head extending over a rib 121 that is formed on the adjacent frame 50. Consequently, when the load has been elevated at distance determined by the entrance of the cable 64 into the last convolution of the drum 35, the arm 118 will be depressed by the cable thereby to elevate the lifter 117 and kick the plug 96 out of the boss 90 and open the circuit, the head 120 of the plug rocking upon the rib 121 during the operation. The load will then be held suspended, without danger of coasting due to the effective locking of the worm gears, until the operator again inserts the plug 96 within the boss 90. WVhen this is attempted, he is restrained, by the elevated condition of the lifter 117, from placing the plug in its former position and is compelled to insert it in its other position which will result in reversing the motor and lowering the load.

A convenient method of elevating the hoist to its suspended position is illustrated in Fig. 3. The cable 64 may. be run oif the drum 35 and carried up a ladder 125 and engaged about a support, such as a beam 126. The plug 108 is inserted in the trolley connection 104, while the switch member 112, through a suitable adapter (not shown), may be engaged with the boss 90 of the motor, thus placing the motor in circuit with the electrical conductors 103 and causing it to operate in a direction to wind up the cable on the drum and by so doing lift the hoist to the desired elevation. The operator then engages the suspension hook 57 of the hoist with the elevis 127 of the trolley, or with any other support from which he desires to hang the hoist. When this is done, he removes the adapter carried by the switch member 112 from the boss 90 and inserts the plug 96, at the same time snapping the brake control cord or cable 88 to the lever 81.

In the manually operated hoist, illustrated in Figs. 8 and 9, the drum is designated 130, and it is supported, through a ball bearing 131, from a frame 132 made up of two side members between which the ball supporting and retaining ring 131 is clamped. A shaft 133 is supported by the which enclose the threaded ends of the worm I 134 and provide lubricant'chambers. Packing rings 139 are interposed between the portions of the casings 137 which surround the openings through which the worm is engaged and adjacent smooth portions that are formed on the worm, thereby to prevent egress of the lubricant and ingress of dust or grit. The two halves of the frame 132 are connected together by bolts 140, the one occurring at the top of the frame mrving as a means for connecting a yoke 141 to the frame, A suspension hook 142 is swiveled to the yoke. connected a loop 143 through which a hook 144, connected to one end of the cable 145, is engaged. The other end of the cable is fastened to the drum, as indicated at 146. It is evident that the present modification To another of the bolts 140 is is susceptible to the same sheave block and cable arrangements as were mentioned in connection with the former embodiment.

Having thus described my invention, what I claim is':

1. In combination, a drum, an internal worm gear carried by the drum, a worm meshing with the worm gear, and means for driving the worm.

2. In combination, a drum, an internal worm gear carried by the drum, a worm meshing with the worm gear, and driving mechanism inside the drum and having operative connection with the worm.

3. In combination, a supporting structure, a drum rotatably supported thereby, an internal worm' gear carried by the drum, a worm rotatably sustained by the structure in mesh with the worm gear, and means for driving the worm. I

4. In combination, a supporting structure, a drum rotatably supported thereby, an internal worm gear carried by the drum, 9.

worm rotatably sustained by the structure in mesh with the wormgear, and driving mechanism carried by the structure and having operative connectionwith the worm.

5. In combination, a supporting structure, a drum rotatably supported thereby, 3.1'1'111- ternal worm gear carried by the drum, a worm rotatabl sustained by the structure in mesh with t e worm gear, said worm incorporating a circumferential, gear, and means for rotating the latter gear.

6. In combination, a supporting structure, a drum rotatably supported thereby, an in-' ternal worm gear carried by the drum, a worm rotatably sustained by the structure in mesh with the worm gear, said worm having a Worm gear about its equator, and driving mechanism sustained by the structure and incorporating a worm meshing with the equatorial worm gear.

7. In combination, a drum, a supporting structure having bearings spaced apart axially of the drum and through which said drum is rotatably su ported by the structure, an internal worm gear extending about the interior of the drum, a worm meshing with the worm gear, and means for rotating the worm.

8. In combination, a drum, a supporting structure having bearings spaced apart axially of the drum and by which said drum is rotatably supported, an internal worm gear extending about the interior of the drum, a worm sustained by the supporting structure in mesh with the worm gear, driving mechanism supported by said structure, and operative connections between said driving mechanism and the worm.

9. In combination, a drum, a supporting structure having bearings spaced apart axially of the drum and by which said drum is rotatably supported, an internal worm gear extending about the interior of the drum, a worm supported by the structure in mesh with the worm gear, said worm in corporating a circumferential gear, driving mechanism carried by the structure, and diving connections between said mechanism and said circumferential gear.

10. In combination, a drum, a supporting structure having bearings spaced apart axially of the drum and by which said drum is rotatably supported, an internal worm gear extending about the interior of the drum, a worm rotatably supported by the structure in mesh with the internal worm gear, said worm having a worm gear extending about its equator, and driving mecha nism carried by the structure and incorporating a worm meshing with the equatorial worm gear.

11. Ina hoist of the class set forth, the

combination of a motor, a drum surrounding the motor and rotatably supported thereby,

an internal worm gear extending about the interior of the drum, and a worm driven by the motor and meshing with the worm gear. 12. In a hoist of the class set forth, the combination of a motor involving a casing, a drum surrounding the motor casing','sai casing having bearing portions in parallel planes spaced apart axially of the drum and whereon said' drum is rotatably supported, an internal worm gear surrounding the interior of the drum, a worm supported by the casing in mesh with the internal worm gear, said worm having a worm gear extending about its equator, and a worm on the motor shaft meshing with .the equatorial worm ear. c 13. In a hoist of the classset forth, the combination of a motor involving a casing, a drum surrounding the motor casing, said casing having bear ng portions in parallel planes spaced apart axially of the drum and whereon said drum is rotatably supported, an internal worm gear surrounding the interior of the drum, a worm supported by the casing in mesh with the internal wormgear, said worm having a worm gear extending about its equator, a worm on the motor shaft meshing with the equatorial worm gear, a brake drum carried by the rotating element of the motor, a brake member supported in operative relation thereto, and vmeans for actuating the brake member.

14:. In a hoist of the class set forth, the

combination of an electric motor of the induction type having a so-called squirrel cage rotor winding in which one'of the end rings is constituted of a cylindrical member serving as a brake drum, the motor involving a casing, a drum surrounding the motor casing, the casing having bearing portions in' a parallel planes spaced apart axially of the drum and through which the drum is rotatably supported, an internal worm gear extending about the interior of the drum, a worm rotatably supported by and within the motor casing in mesh with the internal worm gear, said worm incorporating a'circumferential gear, and driving connections between said circumferential gear and the rotating element of the motor, a brake shoe supported by the motor casing in operative relation to the aforesaid brake drum, and

means exterior of the motor casing for actuating said brake shoe.

15. In a hoist of the class set forth, the combination of an electric motor involving a casing, a drum surrounding the motor cas-' ing, anti-friction bearings throughwhich the drum is rotatably supported upon the motor casing, an internal worm gear extending about the interior of the drum, a worm meshing with the worm gear, and drivin connections between the motor shaft an said Worm.

16. In a hoist of the class set forth, the combination of an electric motor involving a casing, a drum surrounding the motor casabout its equator, the axis of the motor beingthe drum is rotatably supported from the motor casing, an internal worm gear extending about the interior of the drum, a worm enclosed and su ported by the motor casing and meshin with the internal worm gear, said worm aving a worm gear extending inclinedto the plane of the internal worm gear thereby to dispose one end of its shaft alongside said worm, and a worm mounted upon said end of the motor shaft for cooperation with the equatorial worm gear.

17. In a hoist of the class set .forth, the combination of an electric motor involving a casin a drum surrounding the motor casing, all races extendin about the motor casing and spaced apart axially of the drum, ball races fitted to the drum in opposed relation to the former ball races, balls interposed between the opposed ball races, "an internal worm arextending about the interior of the rum, a worm enclosed and supported by the motor casing and meshing with the internal worm gear, said worm having a worm gear extending about its equator, the axis of the motor being inclined to the plane of the internal worm gear thereby to dispose one end of its shaft alongside said worm, and a. worm mounted upon said end of the motor shaft for cooperation with the equatorial worm gear.

18. In a hoist of the class set forth, the

' combination of an electric motor involving a substantially spherical casin a drum surroundin the motor casing, t e motor casmg havmg annular shoulders in parallel planes spaced apart axially of the drum, ball races mounted upon said shoulders, ball races carried by thedrum in opposed relation to the former ball races balls interposed between the opposed races, an internal worm gear extending about the interior of the drum, a worm enclosed and sup orted by the motor casin in mesh with t e internal worm gear, said worm having a worm gear extending about its equator, the axis of the motor being inclined to theplane of the nternal worm gear so as to dispose one of ts ends alongside said worm, and a worm mounted upon said end of the motor shaft andmeshing with the equatorial worm gear.

19. In a hoist of theclass set forth, the combination of, an electric motor involving a casing, a drum surrounding the motor casmg, bearings extending about the exterior of the motor casing andspaced apart axially of the drum and through which the drum is rotatably supported, aninternal worm gear extending about the interior of the drum, a worm within and supported by "the motor casing and meshing with the internal worm gear, one end of the motor shaft being disposed alongside the worm, driving connections between said end of the motor shaft and the worm, and a partition dividing the motor casing into a lubricant containing compartment, enclosing said worm and the driving connection between it and the motor shaft, and a second compartment enclosing the electrical elements of the motor, said partition having an aperture through which the motor shaft extends.

20. In a hoist of the class set forth, the combination of an electric motor involving a casing, a drum surrounding the motor casing, bearings extending about the exterior of the motor casing and spaced apart axially of the drum and through which the drum is rotatably supported, an internal worm gear extending about the interior of the drum, a worm within and supported by the motor casing and meshing with the internal worm gear, one end of the motor shaft being disposed alongside the worm, driving connections between said end of the motor shaft and the worm, a partition dividing the motor casing into a lubricant containing compartment, enclosing said worm and the driving connections between it and the motor shaft, and a second com partment enclosing the electrical elements of the motor, said partition having an aperture through which the motor shaft extends, and av guard surrounding said aperture to prevent passage of lubricant from the first to the second of said compartments.

21. In a hoist of the class set forth, the combination of an electric motor involving a casing, a drum surrounding the motor casing, bearings extending about the exterior of the motor casing and spaced apart axially of the drum and by which the drum is rotatably supported, an internal worm gear surrounding the interior of the drum, a worm within and supported by the motor casing and meshing with the internal worm gear one end of the motor shaft being disposed alongside the worm, driving connections between said end of the motor shaft and the worm, a partition dividing the motor casing into a lubricant containing compartment, enclosing said worm and the driving connections between it and the motor shaft, and a second compartment enclosing 'the electrical elements of the motor, said partition havin an aperture through which the motor sha t extends, and a guard surrounding said aperture to prevent passage of lubricant from the first to the second of said compartments, a brake member carried by the rotating element of the motor, a second brake member carried by said partition for cooperation with the first mentioned brake member, and means exterior of the casing for actuating the second brake member.

combination with a supporting structure, a drum rotatably supportedthereby, an electric motor carried by the structure, brake mechanism for controlling the motor, and a control element including electrical conductors and a switch through which current is supplied to the motor, said element havcontrol element.

In testimony whereof, I hereunto aflix my signature.

THOMAS E. ADAMS.