US2693341A - Man hoist - Google Patents

Description

Nov. 2, 1954 ox 2,693,341

MAN HOIST Filed 001;. 25, 1950 v 3 Sheets-Sheet 1 (mag ATTORNEY Nov. 2, 1954 Filed Oct. 25, 1950 R. P. Fox

mm aors'r 3 Sheets-Sheet 2 INVENTOR.

F g barf F. Fax QMm-fiw ATTORNEY R. P. FOX

Nov. 2, 1954 MAN HOIST 3 Sheets-Sheet 3 Filed Oct. 25, 1950 INVENTOR Robe/'25 P Fox BY M mQN ATTORNEY MAN HOIST Robert. F014,, Duluth, Minn, asslguorto .Clyde Iron! Works, Inc., lz),uluth, Minn,, acorporationv of Minnesota Applieationzflctaher 2.5.1.1950, .senamo. 191,974.

' 7laims. (Cl;.254-.-187) {in object of. the. presentjnvention resides in the. PTO? vision of a hoist drum which may be selectively-driven in either direction by a source of power, such asan internal combustion engine. The device incorporates numerous safety features which make the apparatus useful .in .hoisting men as well as materials.

A feature of.the present inventionlies .in. the provision of a braking, system including two different. types. of.

brakes both of which are normally, applied, by. spring.

pressure p and which; resist rotation of j the,- hoisti'ng. drum.

During theoperation ofthehoish the brake system is connected to the operating control sothatasthe hoisting. drum starts rotation one or, both of thebrakes are; automatically released. In the event of failure of the power supply or of thesystem holdingthe brakes released, thebrakes will immediately be set to stop, the drum tat om.

A feature of. the. present invention, resides, in; the. provision ofga hoisting drum which,maylbe selectively driven in eitherdirectionthrough clutch mechanisms.

controlled by an airsystem In..case of failure ,-of the. air system, theclutche's areJautomaticzdly released so. as .to. disc onnec t the,hoisti ng drum; from theppwersource. Simultaneouslythe air holding thebrake orfbrakeshreleased is. cut off 'thereby permitting the. springsto set-.

the brakes,

A feature of the presentinvention resides. ,in- .the pro vision of ahoisting unit having an. air .systenrcontrolled by .theactuation oflan electrically:operatedyalve... The: circuit to th s valve .include a,,,series of switches. .all of which must be closeddn, orderthat, themachine may.

function.. The circuit-controlling the valyejnclflds an air, pressure switchwhich. is closed. only when sufiicient air s available to actuate the..brak.e. releases andgthe. air.

clutches. The circuit alsoincludcs a governor. controlled switeh' which opens. the control circuit :if the. ,srneed. of J the hoist drum. is excessive., The circuit, also includes.

upper and 'lower limit switches ,whic'hdimitj the. travel of the elevator cage by .breakingthe. circuitfas theelevator cage travels v upwardly or. downwardly too far... The circuit also, includes amanually. operable. switch which jsets thecircuit inoperation. v Openingofgany of.- the switches will thus stop the hoistingoperation and 1 set the brakes;

These and other objects. and. novel features. of] my invention will bemoreclearly and fully set forthrinthe following specification and claims. H y

In the drawings forming a part of myspecifi'cationz', Figure 1v is a side e1evational..view..of the. hoisting apparatus, showing the arrangement of parts therein.

Figure 2 is a top plan view of .the apparatus illustrated inFigu're 1'. Figure 3 isa diagrammatic viewshowingthe electrical A circuit controlling operation of-theapparatus.

The ;man-hoistis indicated in general by the letter A. This device is; preferably mounted. upon a frame of suitable design and construction to support-the apparatus.

. ring-shapedelement 45.encircling the-hub 43. The in- 3 1 2,693,341 Patented Nov. 2, 1954 The frame, 10, usually embodies a pair of generally parallel. beams 11 and 12 connected by suitable cross members suchas 13.

An. internal combustion engine of suitable design is indicated in general by the numeral 1'4;v This engine is designed to provide a suitable source of power for rotatingthe. drive shaft 15. The drive shaft 15 acts-through a chain, 16' to drive a counter-shaft 17. The countershaft17' extends transversely of the frame for a purpose which will be later set forth.

The frame 10 also-supports a pair of opposed bearings 19' which act. to. support. a drum shaft 20. The drum shaft. 20 rotates freely inthe bearings 19 to support the hoisting drum 21.. The. hoisting. drum 21 includes a relatively smaller diameter. center portion 22 onwhich the hoisting eableis wound. The drum. also includes. a larger diameter drum portion 23. for accommodation of. a foot.brake,, aswilli be. later described; The drum 21 is also. provided at. its. other end with a. largerv diameter drum, portion 24 which serves to accommodate a brake of a type which will. berlater. described. The drum-is suppoited atone end. by a. hub 25 mounted upon the shaft 20 to rotate inunison therewith The large diameter portion 23 of: the drum 21 is provided with an intur'ned marginal. flange 26 which is bolted or otherwise connected at. 27 to. a drive. gear. 29. The drive gear 29. is provided with aperipheraltoothed flange 30 which is connected by the body of the gear to a hub 31. keyed or otherwise fixed to the shaft 20. Thus the hoisting, drum 21 rotates in unison with its supporting shaft. 20. A counter-shaft 32 is supported by suitable bearings 33 upon the frame 10.

The shaft. 32 is provided witha pinion 34- connected thereto to rotate inunison therewith. The pinion 34 meshes with the. drive. gear 29 onthe drum shaft. Therefore, rotationv of the counter-shaft- 32 in either direction acts to drive the drum 21- in a corresponding opposite direction.

The. counter shaft 32. is-provided at opposite endswith two clutchunitsindicatedin:general by the numeral 35, 36.. The clutch unit 735 "includes ahub 37 freely rotatable about the shaft 32: and provided-with acylindrical flange 39 forming the clutch drum. The hub 37 is also connected to a cylindrical flange 40' which is externally toothed to form agear. A pinion41 is provided on the counter-shaft 17 and is. of sufficiently small diameter to pass-the" gearteeth onithe flange 40. constantmesh with an'zidler gear 42 which in turn contacts the gear 40: Thus asthe shaft 17 rotates in its driven clockwise direction as viewed-in Figure 2, the pinion 41 is.d'riven in a clock-wise direction acting to rotate the idler gear. 42. inacounter-clockwise direction. This, in turn, causes thegear 40 to rotatein a=clockwise direction. During the operation of. the hoist, as long as "power is being supplied by the engine 14 to the drive shaft 15, this gear40and the .clutch drum=39 connected thereto, rotate freely. inone. direction such as a clockwise direction. However, asthe hub 37 is not-connected to the shaft 32,- suchactiondoes not- .cause rotation of the shaft 32.

The clutch unit .35.also includes a hub 43 which is .keyed.orotherwisevafiixedto the shaft 32 for rotation therewith. The'hub. 43 supports: a circular flange 44, which in .turn supports an expandable and contractable terior of the expandable and contractable element 45'is connected tov asuitable source of air supply which will be later described in detail. so that, when desired, this member 45...may" be expanded into engagement with the drum 39.3 Rotation of the drum 39in a clockwise direction thus causes rotation. of the hub 43 and accordingly the counter-shaft32- Theclutch 36 comprises a similar unitat. the.oppositeendfofltheshaft 32. A-hub 46 is freely -,rotatableupon. the counter-shaft 32 This hub 46 actsthrough a ring-.likeflange 47 tosupport a clutch drum. 49.. The hub 46 alsoacts. to support a ring shaped g ar flange. 50 .which.is-providedwith external teeth. The. gear. 50 is. designed. to meshwith a pinion 51 on a counter-shaft 17. Rotation: of 'the' counter-shaft 17 in a clockwise directionthus drives the gear 50 ina counterclockwise direction. Howevenas the hub-46 is not keyed to.the shaft'32, this rotation is not-transferred to the shaft Thispinion 41 is in' 3 I 32 unless the clutch is in operation. The gear thus continually rotates about the shaft 32 in a direction of rotation opposite that of the gear 40 encircling the other end of the shaft. y z

A hub 52 is mounted upon the shaft 32 for rotation therewith. This hub 52 supports a circular flange 53, which in turn supports an expandable and contractable clutch member 54 encircling the drum 49. The expandable and contractable member 54 is connected in a manner which will be later described in detail to a suitable source of air supply so that when desired the element 54 may be expanded into contact with the clutch drum 49. Such expansion causes counter-clockwise movement of the shaft 32 in unison with the gear 59.

Thus it will be seen'that the hoisting drum 21 may be rotated in either direction by actuation of the clutch unit 35 or the clutch unit 36. Obviously the clutch units 35 and 36 are not simultaneously operable. As previously stated the enlarged diameter portion 23 of the hoisting drum is encircled with a foot brake. This foot brake is best illustrated diagrammatically in Figure 3 of the drawings. It will be noted that the drum portion .23 is partially encircled by a brake band 55 which is dead ended at 56. The other end of the brake band 55 is connected at 57 to one end of a bell crank lever 59 supported intermediate its ends upon. a transversely extending operating shaft 61. The other end of the bell crank lever 59 is connected at 60 to a spring arm 62 which is supported by a fixed bracket 63 and which supports a collar 64. A spring 65 is mounted between a fixed part of the frame and the collar 64, thus exerting an upward force upon the arm 62 and tending to rotate the bell crank lever 59 in a counter-clockwise direction. This action tends to tighten the brake band 55 about the drum 23. Thus the brake 55 is normally held wrapped tightly about the drum portion 23 by the spring 65.

As indicated in Figure l of the drawings, the shaft 61 extends through the frame 10 and is rotatably supported thereby. This shaft 61 is provided with a foot lever 66 by means of which the shaft 61 may be rotated in a counterclockwise direction. Thus the brake band 55 may be set by downward pressure upon the foot lever 66 and the brake may be manually controlled. An arm 67 is mounted upon the shaft forrotation therewith. A piston rod 69 is pivotally and slidably connected to the arm 67 and is connected to a piston with an air cylinder In Figure 3 of the drawings, the cylinder 70 is diagrammatically illustrated and is shown enclosing a piston 71. When air is applied to the piston 71 in the cylinder 70 a downward force is exerted upon the arm 67, thereby rotating the shaft 69 in a clockwise direction and releasing the brake 55 against the tension of the spring 66.

A post brake is also illustrated, this brake being shown diagrammatically in Figure 3 of the drawings. In the form of construction illustrated the post brake includes a pair of brake shoes 72 and 73 which are pivotally supported to the frame at 74 and 75 respectively. A bell crank 76 is pivotallv connected to the shoe 73 at77. A link 79 connects one end of the brake shoe 72 to one end of the bell crank 76. A rod 80 is pivotally connected to' the other end of the bell crank lever. This rod 80 extends through the upper end of an inverted U-shaped bracket 81 and a spring 82 is interposed betweenthe top of the bracket 81 and a collar 83 on the rod 80. The spring 82 thus tends to rotate the bell crank lever 76 in a clockwise direction about its pivot 77, thus drawing both of the brake shoes 72 and 73 against the enlarged portion 24 of the drum 21.

A pneumatic cylinder 84 contains a piston 85. connected by a connecting rod 86 to the lever 7 6. Air pressure below the piston acts to pivot the bell crank lever 76 in a counter-clockwise direction, compressing the spring 82 and releasing the brake shoes 72 and 73.

The operating system for operating my host includes the necessary internal combustion engine controls, not illustrated in the drawings. The device also includes a pneumatic electrical system which forms a part of the present invention. The air system includes an air supply tank or reservoir 87 which is kept. supplied with air by an engine mounted air compressor. The air reservoir 87 is connected by a tubular connection 89 to a pneumatic control valve 90 which is opened and closed by means of a solenoid 91. The valve 90 is always closed when there is no electrical current flowing through the solenoid coil and is always open whenv current does flow through this coil.

From the valve 90 the air flows through the tubular connection 92 to the air control valve 93. This valve is closed when in the central position illustrated and is pivotally arranged to selectively connect the air supply to a tubular connection 94 or to a tubular connection 95. When the control lever 96 of the control 93 is swung in a clockwise direction, as viewed in Figure 3, air flows through the connection 94 to the expandable and contractable clutch member 45, thus rotating the winding drum in a lowering direction. If the control lever 96 is pulledbackwardly in. a counterclockwise direction, the connection is opened, thereby communicating air pressure to the expandable and contractable member 54. Air pressure in the member 54 acts to rotate the hoisting drum 21 in a lifting direction.

When the connection 95 communicates with the air supply, air may also travel through the tubular connection 97 leading to the brake cylinder 84. When air enters the cylinder 84, it actsto release the post brake in a manner which has been previously described. Thus the post brakes are automatically released by the air system when the control lever is in position to wind cable upon the drum 21 to lift the load. With the control lever in the opposite position to lower the load, air is not communicated to the cylinder 84, and the spring 82 holds the post brakes engaged during rotation of the drum in a lowering direction, acting against the tension of the post brakes.

The air connection 92 is also connected by a tubular connection 99 to air cylinder 70 so that the foot brake is automatically released when air pressure is present in the system. Thus the brake56 is normally held in released position by the air cylinder 70, this action compressing the spring 65 and thereby counteracting the effect of the spring pressure. The brake 55 may then be set by means of the foot lever 66 so that the raising or i lowering of the load may be controlled by action of the operator, foot pressure on the lever 66 urging the shaft 61 in the same direction that said shaft is biased by the spring 65.

The circuit to the solenoid valve 91 includes a series of safety switches all of which must be closed in order to provide air in the system. One terminal of the solenoid coil 91 is connected by, the conductor 100 to the source of power supply 101. The other terminal of the power supply 101 is grounded as indicated at 102. The second terminal of the solenoid coil 91 is connected by a conductor 103 to a switch 104 by means of which the entire system may be placed into or out of operation. This switch 104 is always closed when the apparatus is in use. The second contact of switch 104 is connected by conductor 105 to a lower limit switch 106 which is arranged in the path of movement of the hoist platform so as to open the circuit in the event the hoist platform moves downwardly near the limit of its travel. In other words, the switch 106 forms a safety switch which opens the circuit when the hoist car on the platform drops too low.

A similar upper limit switch 107 is connected to the switch 106 by a conductor 109. The limit switch 107 has a capacity similar to that of the switch 106, the switch 107 tending to limit the upward movement of the hoist car or platform. This switch 107 opens the circuit to the solenoid 91 of valve 90 in the event of upward over-travel of the hoisting platform.

The switch 107 is connected by a conductor 110 to a governor actuated switch 111 actuated by the governor 112. Thus upon an increase in the speed of rotation of the engine or of the drum 21, the governor 112 tends to break the operating circuit and to stop the device from further operation.

The governor switch 111 is connected by conductor 113 to a pressure actuated switch 114 which is actuated by pressure in the air pressure system. The other terminal of the pressure switch 114 is grounded as indicated at 118. Thus, if insuflicient pressure is present in the system to actuate the necessary mechanism, the switch 114 will hold the device from operation by breaking the circuit to the solenoid 91.

A short circuiting switch 115 is connected between the ground 116 and the. conductor 103 leading to the solenoid coil 91. As a result, the system may be temporarily set into operation by closing the switch 115 if any of the other switches cease to function. For example, if the circuit is opened through the switch 106 or 107, the device may be set back into operation by temporarily closing the short circuit switch 115 which cuts out the various safety switches. Similarly, if the switches 111 or 114 should not function in the manner described or should either of these switches be opened, the circuit to the solenoid 91 is opened and the solenoid valve 90 de-energized to close the system from air.

It will be noted that my man hoist is virtually fool proof in operation and can not readily fail to function. The two sets of brakes are at all times urged toward closed position by suitable spring means and these brakes may only be held in open position by a supply of air. In the event the air system should fail, the springs would automatically set the brakes.

The hoisting operation is similarly controlled by air, the clutches being selectively actuated by air pressure. In the event air pressure should fail, the clutches will be automatically disengaged simultaneously with the setting of the brakes. Thus the hoisting operation or lowering operation can not continue to function in the event the air supply should fail.

The electrical system must also function in order to control the operation of the hoist. In the event the electrical system shall fail the air will not function and the brakes will be held in closed position. Thus in almost any type of accident the brakes on the hoist drum will hold the drum from rotation and the hoist drum will merely stop wherever it happens to be. Thus there is little likelihood of accident or of injury to the men or materials being hoisted.

In accordance with the patent statutes, I have described the principles of construction and operation of my hoist, and while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that obvious changes may be made within the scope of the following claIimls without departing from the spirit of my invention.

arm:

1. A hoisting system including a hoisting drum, a power supply for rotating said drum, a pair of fluid actuated clutches selectively connecting said power supply to said drum to selectively drive said drum in either direction, a control for selectively directing fluid to either of said clutches, a fluid s pply connected to said control, and a valve controlling e flow of fluid from said fluid supply to said controlgagpair of brakes independently operable to resist rotation of said drum, resilient means connected to each of said brakes to normally apply the brake, fluid operated means for'releasing each brake, one of said last named fluid operated means connected to said valve to urge the corresponding brake toward released position at all times when said valve is open, and means connecting the other of said fluid operated means to one of said clutches to release said other brake when said one clutch is subjected to fluid.

2. The structure described in claim 1 and in which said valve is electrically controlled and including a circuit including manually operable switch for controlling said va ve.

3. The structure described in claim 1 and in which said valve is electrically operable, and including a circuit for said valve including aseries of switches arranged in series.

4. A hoisting system including a hoisting drum, means for actuating said drum, a pair of fluid actuated clutches selectively connecting said drum with said power supply to selectively rotate said drum in either direction, a control for selectively directing fluid to either of said clutches, a source of fluid supply connected to said control, an electrically actuated valve for controlling opening and closing of the connection between said control and said fluid supply, circuit means including means for actuating said electrically operated valve, and pressure actuated switch means in said circuit for preventing the opening of said electrically operative valve if insufficient pressure is provided'in said fluid supply.

5. A hoisting system including a hoisting drum, means for actuating said drum, a pair of fluid actuated clutches selectively connecting said drum with said power supply to selectively rotate said drum in either direction, a control for selectively directing fluid to either of said clutches, a source of fluid supply connected to said control, an electrically actuated valve for controlling opening and closing of the connection between said control and said fluid supply, circuit means including means for actuating said electrically operated valve, a series of safety switches in said circuit, said switches being normally closed and operable when open to open the circuit to said electrically operated valve to close the valve, and a short circulating switch for actuating said valve when one of said safety switches is in open position.

6. A hoist comprising a hoisting drum, a pair of concentric clutch drums for driving said hoisting drum in one direction, a second pair of concentric clutch drums for driving said hoisting drum in a reverse direction, an expandable and contractible ring-shaped element interposed between each pair of clutch drums, a source of fluid supply for expanding said ring-shaped elements to provide a driving engagement between their respective clutch drums, a pair of independent brakes for holding said hoisting drum from rotation, fluid actuated means for holding said brakes inoperative, means connecting one of said last named fluid actuated means to one of said ring-shaped elements for operation in unison therewith, means connecting the other of said last named fluid actuated means to said source of fluid supply to operate when said fluid supply source is functioning, and means for selectively directing fluid to either of said ring-shaped elements.

7. The structure defined in claim 6 and including manually operable means for actuating one of said brakes in opposition to the said other fluid actuated means.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,012,003 Pearson Dec. 19, 1911 1,134,541 Lane Apr. 6, 1915 1,476,989 Massey Dec. 11, 1923 1,549,447 Castleman Aug. 11, 1925 1,621,700 Wilson Mar. 22, 1927 2,326,935 Ferguson Aug. 17, 1943 2,513,812 McClay July 4, 1950

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