US2489913A

US2489913A - Hoist control mechanism

Info

Publication number: US2489913A
Application number: US670640A
Authority: US
Inventors: Henry H Logan
Original assignee: Logan Engineering Co
Current assignee: Logan Engineering Co
Priority date: 1946-05-17
Filing date: 1946-05-17
Publication date: 1949-11-29
Anticipated expiration: 1966-11-29

Description

Nov. 29, 1949 Filed May 17. 1946 H. H. LOGAN HoIs'r CONTROL. MECHANISM 5 Sheets-Sheet l Nov. 29, 1949 H. H. LOGAN HIST CONTROL MECHANISM 5 Sheets-Sheet 2 Filed May 17, 1946 5 Sheets-Sheet 3 Filed May 17, 1946 Nov. 29, 1949 H. H. LOGAN 2,489,913

HOIST CONTROL MECHANISM Filed May 17. 1946 5 Sheets-Sheet 4 Nov. 29, 1949 H. H. LOGAN HOIST CONTROL MECHANISM 5 Sheets-Sheet 5 Filed May 17, 1946 Patented Nov. 29, 1949 UNITED STATES PATENT OFFICE 2,489,913 Y nois'r CONTROL MECHANISM Henry H. Logan, Chicago,

Engineering Co., Chicago, Ill., a corporation of Illinois Ill., assignor to Logan Application May 17, 1946, Serial No. 670,640

` with other electrical and mechanical hoist control apparatus for automatically controlling certain phases of the hoist operation.

One of the objects of this invention is to provide a hoist control mechanism adapted to be driven from the hoist drum for electing automatic control of hoist movements and wherein the operating parts are so constructed and arranged that they function within an enclosure and are readily lubricated.

As another object my invention comprehends the provision of a hoist control mechanism which, although adapted to compact construction and the occupation of a relatively small space, eiects accurate and consistent control of a hoist without requiring extreme accuracy in the machining of incorporated parts.

It is a further object of my present invention to provide a hoist control mechanism wherein cams are utilized to eifect automatic control ot the hoist operation after the hoist is manually started by an operator, and wherein said cams remain stationary during the major portion oithe hoist travel and are rendered effective for. control purposes near and at the ends of the hoist travel.

An additional object of the invention is to provide a hoist control mechanism of the type referred to in which the automatic control of the mechanism may be supplemented at any time by the manual control of the operator.

Other objects and advantages Of the invention will loe apparent from the following description and the accompanying drawings, in which similar characters of reference indicate similar parts throughout the several views.

Referring to the drawings, of which there are five sheets,

Figs. 1, 2 and 3 are, respectively, front, side and rear elevational views of a hoist control mecha nism embodying a preferred form of my present invention;

Fig. 4 is a fragmentary side sectional view of 'a portion of the mechanism shown in Figs. 1, 2 and 3, wherein the section is taken substantially on a line 4-4 of Fig. 5 and in the direction indicated by the arrows;

Fig. 5 is a front elevational view or a portion of the mechanism shown in Fig. 4 with the cover removed so that the view is effectively taken substantially on a line 5-5 of Fig. 4 and in the direction indicated by the arrows; and

Fig. 6 is a fragmentary and partially diagrammatic view which illustrates schematically a portion of the hoist-operating and control parts with which my preferred control mechanism is adapted i to operate.

The hoist control mechanism disclosed herein for illustrative purposes is adapted to operate in conjunction with a part of the hoist-operating mechanism, such as the hoist drum, which has a position correlated to that of the hoist. In its operation my disclosed control mechanism functions in conjunction with other parts of the hoist control apparatus, such as the electrical controls for an electrically operated hoist, to supplement the manual control of the hoist by affecting automatic control of the hoist deceleration and speed during its travel and automatically stopping the hoistrat predetermined normal positions. In my preferred construction, however, the automatic control effected by the disclosed mechanism may be supplemented by manual control when such manual control is necessary or desirable because of an abnormal condition or circumstance.

As a practical matter, the acceleration and deceleration of the hoist normally occur at the extremities ofY its movement between the predetermined stopping positions. The speed of the hoist inV the intermediate portion of the travel between those positions is virtually uniform. It, therefore, follows that if the controlling portion of the hoist control mechanism travels continuously during the movements of the hoist. it must be unduly large, especially in instances in which the holst travel is long, in order to provide the required accuracy and rate of control near and at the ends of the movements. In the present exemplary embodiment of my invention, I have disclosed a hoist control mechanism in which the controlling portions of the mechanism are not only accurate and positive in their action, but the size of the mechanism is materially limited by virtue of the fact that those controlling portions function by movement only during the desired variable portions of the hoist travel.

In addition to the foregoing features, the construction and arrangement of my hoist control mechanism are such that its mechanical driving parts operate within an enclosure with an adequate supply of lubricant and so as to be protected from dirt.

Having reference to the accompanying drawings, and particularly to Figs. 1, 2 and 3, my hoist control mechanism has a base lll which provides a main support for the operating parts and inportion I2 by which the suitable foundacludes 'a iianged lower mechanism may be secured to a tion.

On one end of the base I9 and intermediate the top and bottom thereof, a flanged gear box I3 is removably secured thereto by fastening means, such as cap screws I4. Removably secured to the outer end of the gear box I3 by cap screws I5 is a flanged end cover I6. A shaft I1 extends through an opening in the end cover I6 and is journaled in bearings IB and I9 supported in spaced relationship within the end cover i6 and gear box I3, respectively. Within the gear box and adjacent a shoulder on the shaft I1 a pinion 22 is drivingly connected to the shaft and disposed between the bearings I8 and I9. The shaft I1 projects outwardly from the end cover I6 and is desirably provided with a keyway 23 so that it may be connected to a portion of the hoist mechanism, which is continually dependent upon the hoist position, to be driven thereby.

At its top the base I8 has a main bearing bore 24, as shown in Fig. 4, the axis of which is parallel to the axis of the shaft I1. In the disclosed structure, sleeve bearings 25 and 26 are mounted in opposite ends of the main bearing bore 24 and rotatably support a hollow hub 21 which is coaxial with and projects from one end oi a substautially cylindrical drum 28. Desirably, the

hub 21 is integrally formed with the drum 28 and is connected thereto through an intermediate supporting web 29. A shoulder 36 on the supporting web 29 adjacent the inner end of the hub 21 engages a projecting flange 32 at the inner end of the main bore 24 axially to locate the drum and hub relative to the base. At the outer end the hub is secured in place by fastening means, such as a removable collar or nut 33. which abuts a shoulder 34 on the hub and extends radially to overlap the base at the end of the bore 24 opposite the projecting flange 32.

By preference, a circumferential channel 35 is provided in the interior of the main bearing bore 24 between the bearings 25 and 26 and radial passages 36 extend through the hub 21 to provide communication for the flow of lubricant from a circumferential channel 31 in the mid-portion of the interior of the hub 21 to the channel 35 and thence to the surfaces of the bearings 25 and 26.

Sleeve bearings 3B and 39 are mounted in the opposite ends of the hollow hub 21 rotatably to support a shaft 40 in coaxial relationship to the hub 21 and bearings 25 and 26. At each end the shaft 48 extends beyond the ends of the hub. A gear 42 is mounted on the outer end of the shaft 46 and is drivingly connected thereto by means, such as a key 43. The gear 42 meshes with the pinion 22 so that the shaft 49 is driven by force applied through the shaft I1. As illustrated in Fig. 2, an upper housing 44 adjoins the upper portion of the gear box I3 and the upper portion of the base adjacent the end of the main bearing and provides an enclosure for the gear 42.

The other end of the shaft 49 extends into the interior of the cylindrical drum 28 and has a pinion 45 drivingly secured thereto by means, such as a key 46, as shown in Fig. 4. A spacing washer 41 is desirably provided at the end of the shaft 49 between the pinion 45 and the inner end of the hub.

At a position displaced from the axis of the shaft 40, the supporting web 29 of the drum carries a stud shaft 48 which extends axially of the drum and has portions 49 and 58 of different diameters connected by a tapered mid-portion 52.

For supporting and securing the stud in position relative to the supporting web 29, in the present instance, I have provided an integral and axial extension 53 on the end of the stud adjacent the portion 49 which extends through a. bore 54 in the supporting web and has its end threaded to receive a nut 55 which holds the stud in piace. By preference, a spacing washer 56 is mounted on the axial extension 53 of the stud and is secured between the inner face of the supporting web 29 and a shoulder 51 on the stud. The washer 56 extends outwardly beyond the periphery of the portion 49 0f the stud.

A cluster gear 58 has an axial bore 59 of diameters such that it ts over the portions 49, 50 and 52 of the stud and has

sleeve bearings

69 and 92 secured in opposite ends thereof for rotatably supporting the gear on the portions 49 and 50 of the stud. At its inner end the cluster gear 58 is spaced from the supporting web 29 of the drum by the face of the Washer 56 which extends radially beyond the periphery of the stud portion 49. The cluster gear 58 includes as integral parts a gear 63 and a pinion 64. The gear 63 is substantially flush with the inner end of the cluster gear and meshes with the pinion 45 on the inner end of the shaft 49 to be driven thereby. At the outer end of the stud 49 and adjacent the end of the pinion 64, additional support is provided for the outer end of the stud by a bearing block 65 which has a bearing bore 66 through which the end of the shaft extends and which is secured by fastening means, such as screws 61, to suitable bosses on the interior of the drum (Figs. 4 and 5).

As depicted in Figs. 4 and 5, a bracket 6B is integrally formed on the interior of the drum and has side walls 69 extending in an axial direction into the drum from the supporting web 29. In the disclosed structure, the position of the bracket 68 is eccentric to the axis of the drum and displaced toward the side of the drum opposite that upon which the stud 48 is secured. The side walls 69 of the bracket are spaced from opposite sides of the shaft 4II and pinion 45. A plate 10, having a stud shaft 12 integral therewith, is secured to the projecting ends of the walls 69 by fastening means, such as cap screws 13. The axis of the outwardly projecting stud shaft 12 is parallel to the axis of the drum and eccentrically disposed relative thereto.

A driven gear 14 has a sleeve bearing 15 rotatably carried on the stud shaft 12 and is axially spaced from the surface of the plate 19 by a spacing washer 16. At its outer end, the gear 14 is held in place on the stud 12 by a cap 11 which is removably secured to the end of the stud by fastening means, such as a screw 19, and has a marginal portion overlapping the end of the gear hub. Rotation of the cap 11 relative to the end of the stud is desirably prevented by means, such as a pin 19, extending through the cap and axially into the end of the stud shalt at one side of the screw 18. When thus mounted, the gear 14 meshes with the pinion 64 of the cluster gear to be driven thereby.

The outer marginal portion of the driven gear 14 adjacent the teeth thereof is provided with a faced front surface which faces outwardly toward the end of the drum. In the mid-portion of the faced surface 89, a circumferential T slot 92 is provided to retain a plurality of outwardly projecting fastening elements, such as cap screws 83. At at least one position around the gear, an opening 84 extends from the T slot to the rear surface of the gear through which,

sensatie S the fastening elements are inserted into the slot. The fastenlngelements, thus held in the sl'ot and movable circumferentially of the gear, are utilized for adjustably securing stops and 86 against the facedsurface 00 of the gear.

Axially of the drum, the

stops

85 and 86 are aligned With the side surfaces 0512 and 653/ of the bearing block 65. The stops 85 and 86 have outwardly projecting portions 61 and 88, respectively, which are adapted to engage the opposite side surfaces 65a: and 653/ of the bearing block 65 when the driven gear is rotated to either of the positions for effecting such engagement. One of the stops engages one side of the bearing block upon rotation of the gear in one direction and the other of the stops engages the other side of the bearing block upon rotation of the gear in the opposite direction. When such engagement of either of the stops with one side of the bearlng block 65 occurs during the rotation of the driven gear, that driven gear is no longer free to rotate relative to the drum 2B and the stop 'serves as a driving connection to the drum and through which the drum is driven by the conti'nuetl application of driving force through the shafts and 40 and the various gears. Thus the drum-driving mechanism, which comprises the various shafts and gears, provides for an intermediate period 4of rotation of the gears when they are actuated by the hoist-driving mechanism, which intermediate period of rotation is terminated at either end by a period in which the drum is driven in response to the hoist movement.

In order to provide a sealed closure Within the 'drum 28 to protect the parts enclosed therein from dirt and to hold-a supply of lubricant for the gears and bearings, an end plate 39 is secured to the outer end surface of the drum by fastening means, such as a series of screws 90. A knob 92 at the mid-portion of the outer surface of the end plate '89 provides a handle for the removal and placement of the end plate.

Although there are various ways in which the drum 28 might be biased to a normal position of rest, I prefer to accomplish this result by the use of suspended Weights, such as 93, which are connected to the drum through a flexible cable 94 and a coupling yoke 95, as shown in Figs.

1, 2 and 3. The yoke 95 is rotatably connected to a lug 96 by a pin 81, which lug ls secured to the periphery of the drum at the end of the drum which is adjacent the base l0. At the top of the base I0 a bracket 98 is secured thereto by suitable fastening means, 'such as cap screws 99, and has at its topV pulley-carrying arms |00 and |02 extending toward opposite sides of the base and optionally usable, depending upon the side of the base at which the weights 93 may be more conveniently suspended. In the present instance, and as shown Ain Figs. 1, 2 and 3, guide pulleys |03, |04 and |05 are rotatably mounted upon the bracket arm |02 by suitable supporting pins |06, |01 and |06, respectively. The pulleys |03, |04 and |05 are Vmounted in positions and are so angularly` disposed that they guide the cable 94 upwardly from the lug 96 and to a position of suspension at one side of the base such that the Weights 93 Vare free to move vertically with the cable.

When the drum 2l is free to turn, as in an instance when it has been driven to an extreme position in one direction and then the driving force is reversed, the biasing force of the weights moves the drinn to a position such that the lugY 981s adjacent' one side of the piliey |03. The biasing force of the weights 93 also holds the drum in its normal position when neither of the stops or 46 ls in engagement with the side surfaces 65m and 651/ of bearing block 65. However, a groove |09 is provided in the periphery of the drum in alignment with the lug 96 so that when thedrum is rotated by force applied through the drum-driving shafts and gears, the cable 94 will be wound around a portion of the periphery of the drum and retained in the groove. With the particular biasing system disclosed, the movements of the drum are preferably limited to less than one-half of a revolution from the normal position in either direction.

On its outer surface, the drum 28 has a plurality of axially separated and radially projecting cam-carrying flanges H0, |`|2 and ||3. One of the radial faces of each cam-carrying flange H0, ||2 and l I3 has therein a circumferential T slot adapted slidably to receive a plurality of axially projecting fastening elements, such as bolts ||4 (Fig. l); said T slots in the respective flanges being designated by the numerals H5, H6 and IIT. In at least one circumferential position on each of the flanges, a bore IIB (Fig. 4J opens into the wider portion of each of the T slots to provide an opening for the insertion of the fastening elements into the slots.

As shown in Figs. 1 and 2, cams ||9 and |20 are adjustably secured in circumferentially and axially displaced positions upon the cam-carrying flanges ||0 and ||2, respectively, by the fastoning elements ||4 and coacting nuts |22. In like manner, in the instance of the presently disclosed structure, a plurality of cams |23 and |24 are adjustably secured in circumferentially displaced positions to the cam-carrying flange ||3.

In the disclosed embodiment of my invention, cam followers comprise rocker arms |25 and |23 mounted for swinging movement on a shaft |21 whichv is secured to and projects from the base iii in a direction parallel to the axis of the drum and in a position displaced to one side of the drum. The rocker arms |25 and |26 have intermediate bearing portions |28 and |29, respectively, mounted on the shaft. One end of the bearing portion |28 abuts a boss |30 on one side of the base and the two bearing portions are separated by a spacer collar |32. At the outer end of the shaft a collar |33 holds the bearing portions in their positions upon the shaft. On opposite sides of the bearing portion |23 of the rocker arm it; oppositely projecting arms |34 and |35 carry cam-following rollers |36 and |31, respectively, which are aligned for coaction with the earns 9 and |20. The rocker arm |26 desirably has only one laterally projecting arm |38 and carries a roller |39 aligned for coaction with the surface of either of the cams |23 or |24. In each instance the rollers are rotatably secured to their respective arms by means, such as pins |40.

As indicated in Fig. 1, compression springs |55 and |52 encircle portions of each of the control operating rods |46 and |41 on opposite sides of the respective connector blocks and each have an end abutting one of the blocks. At the opposite ends of the springs, collars |53 and |54 are adjustably secured to the control operating rods and abut the outer ends of the springs to hold those springs against the ends of the connnector blocks. The compression of the springs |50 and |52 in each instance is adjusted to an amount such that it will transmit sufficient force to the control operating rods from the rocker arms normally to actuate the respective control operating rods and the hoist control apparatus connected thereto. However, the springs |50 and |52 provide suiiicient flexibility in the connection between the control operating rods and the respective rocker arms that in some necessary and somewhat abnormal circumstances the control operating rods can be actuated manually to positions other than those effected by the control mechamsm.

In the illustrated embodiment of my invention, the cams i9 and |20 each have a contour adapted to control the deceleration of the hoist 'in one of its directions of movement. To eiect such control. one of the rollers |36 or |31 is biased toward its respective cam by force applied to the rocker arm |42 through the control rod |46. The subsequent movements of the rocker arm |42 and control operating rod |46, which are effected by the movements and proles of the cams H9 and |20 actuate appropriate control apparatus, such as electrical controls (not shown) which in turn determines the speed and deceleration of the hoist.

The cams |23 and |24, which are mounted in coplanar relationship, actuate the rocker arm |26 to effect control of the hoist-braking mechanism at separated hoist-stopping positions. Since the hoist-braking mechanism has only two extreme positions, i. e., off" or on, and intermediate variable positions for each stopping position of the hoist, it may be controlled by a single cam follower and circumferentially separated cams |23 and |24 in the same operating plane.

Referring to the diagrammatic illustration in Fig. 6, my hoist control mechanism is connected through coacting gears |55 and |56 to be driven in dcnite and predetermined relationship from the hoist cable winding drum |51: the gear |55 being drivingly connected to the shaft |1 of the control mechanism and the gear |56 having positions continually related to the hoist position. Thus, the movements of the cam-carrying drum 28 are determined by the position of the hoist. Since there is no normal need for the application of the hoist brakes during the intermediate portion of the hoist travel and since that intermediate portion of the hoist travel may be at a substantially constant speed, the disclosed hoist control mechanism need not eiect any variations in the hoist speed or brake setting during the time of the intermediate portion of the hoist travel. On the other hand, to promote accuracy in the hoist control at and near the ends of the hoist travel without extreme accuracy in the cam profiles and positions, the cam-carrying drum 28 desirably travels through a considerable arc of movement at and near the stopping positions of the hoist. To effect such operation of the camcarrying drum, whereby it is driven only at the 8 ends of the hoist travel and at rates proportional to that of the hoist, the stops and B6 on the driven gear 14 are adjusted to positions such that they engage the bearing block 65 to drive the drum when the hoist is approaching one of its limits of movement.

As the hoist moves away from one of its stopping positions, the reversal of the rotation of the shafts and gears of the hoist control mechanism from those which followed the movement of the hoist toward that position, tends to move the last

engaged stop

85 or 86 away from the bearing block 65. Due to the biasing force of the weights 93, which are connected to the cam-carrying drum, the drum follows the reversed movement of the stop until it reaches its normal position determined by the position of the lug 96 thereon. Subsequent continued movement of the hoist in the same direction rotates the shafts and gears of the hoist control mechanism without turning the drum until the other one of the stops B5 or B8 engages the bearing block 65. It may thus be understood that the positions of the

stops

85 and 86 are selected to effect the rotation of the cam-car- Y rying drum when the hoist is near its limits of travel.

The positions of the hoist speed and deceleration control cams I9 and |20 are so selected that both are ineiiective during the intermediate portion of the hoist travel, and each eiects control of the deceleration of the hoist during its movement in one direction. The brake control cams |23 and |24 have positions on the drum such that they each effect application of the hoist brakes as they approach a stopping position in one direction. The brake control cams also retain the brake application while the hoist is stopped.

With the rocker arms |25 and |26 in the positions depicted in solid lines in Fig. 1, the hoist would be stopped at one of its stopping positions. To start the hoist from that position the brake would be manually released by force applied against the biasing force of the spring |58 and the rocker arm |25 would be moved to a position such as that illustrated in dot and dash lines at |25a, which movement of the rocker arm |25 would place the roller |36 in a position such as that indicated at |36a. wherein it is aligned for engagement with the cam I I9. The initial movement of the hoist produces the resultant movement of the cam-carrying drum which moves the brake control cam away from the following roller |39 so that the biasing force of the spring |50 and brake-releasing force applied through the control operating rod |41 move the rocker arm |26 to a position such as that indicated in dot and dash lines at |26a, in which latter position the brakes remain released until the following roller |39 is engaged by the other of the brake control cams.

As indicated diagrammatically in Fig. 6, the manual force for starting the hoist in either direction is applied to the control operating rods |46 and |41 by suitable manually operable elements, such as levers |58 and |59, respectively.

`The lever |58, which is connected to the hoist speed control rocker arm, has three normal operating positions. The neutral position, in which the hoist is stopped, is shown in solid lines, while the positions for effecting upward and downward movements of the hoist are indicated in dot and dash lines at |58a and |5811, respectively. The brake control lever has two limiting positions; one of which is indicated in solid lines and the other of which is shown in dot and dash lines at |59a. After the hoist is started, the manual control levers follow the positions determined by the speed and brake control cams.

With the springs |50 and |52 interposed between the rocker arms and their respective control operating rods, the holst may be moved by manual control in either direction from either of the positions at which it is stopped by the automatic control of the disclosed hoist control mechanism. Although the springs |50 and |52 are sufficiently strong to effect normal movement of ,the control operating rods, their respective biasing forces may be manually overcome to move the control operating rods after they have been actuated to their hoist-stopping positions by the control mechanism. In any instance, the release of the brake during the starting of the hoist is effected by actuation of the control operating rod |41 against the biasing force of one of the compression springs |50 or |52.

From the foregoing description of a preferred embodiment of my hoist control mechanism, it may be readily understood that I have provided a mechanism which renders accurate, dependable and effective control of the hoist speed and brakes, which control is continuously dependent upon the position of the hoist. The disclosed control mechanism further provides accurate control of the hoist in relation to its position without being unduly large in size and without requiring extreme accuracy in the cams and their adjusted positions. The mechanism permits manual control of the hoist position under circumstances such as the premature stopping of the hoist while it is carrying an abnormally heavy load or the like. In addition, the working parts of the mechanism are enclosed for eil'ective lubrication and to protect them from dirt.

While I have illustrated a preferred embodiment of my invention, many modications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details oi' construction set forth, but desire to avail myself of all changes within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

l. A hoist control mechanism adapted to be driven from the hoist drum and comprising in combination, a base providing a main support and having a main journal bearing therein, a substantially circular drum having an integral hub disposed coaxially therewith and projecting from one end thereof, said hub being journaled in said main bearing to support the drum for rotation relative to the base, and said hub having an axial opening therethrough and bearings carried therein, a shaft journaled in the last mentioned bearings and projecting from both ends of the hub, a drive gear drivingly connected to the end of said shaft opposite the drum, a pinion secured to the other end of the shaft within the drum, a driven gear, means for rotatably supporting the driven gear within the drum with its axis of rotation eccentric to that of the drum, gear and pinion means within the drum and drivingly connecting said driven gear to said pinion on the shaft, stop means within said drum and secured thereto, stop means adjustably secured to said driven gear and disposed for engagement with the stop means in the drum so that when one stop means engages the other relative rotation between the driven gear and drum is stopped and said drum is rotated by force applied to said gear and pinion means by said pinion on the shaft, means for biasing the drum to a predetermined position relative to the base, cam means carried at peripherally adjustable positions on the exterior of the drum, cam followers carried by the base and aligned with each of said cam means, means connected to each of said cam followers Vfor controlling the operation of the hoist, and means for rotating said drive gear in direct relationship to the rotation of the said hoist drum so that the operation of said control mechanism is directly related to the position of the hoist.

2. A hoist control mechanism adapted to be driven from the hoist drum and comprising, in combination, a base providing a main support, a substantially circular drum, means for supporting the drum relative to the base for rotation about its central axis, a shaft, means rotatably supporting the shaft ccaxially with the drum, a pinion at one end of the shaft and driven thereby, means for driving said shaft from the hoist drum. a driven gear, means on said drum for rotatably supporting said driven gear, gear and pinion means supported for rotation relative to the drum and drivingly connecting said driven gear to said pinion on the shaft, stop means mounted at a predetermined position on said drum, stop means adjustably secured to said driven gear and disposed for engagement with the stop means in the drum during rotation of the driven gear so that when one stop means engages the other relative rotation between the driven gear and drum is stopped and said drum is rotated by force applied to said gear and pinion means by said pinion on the shaft, means for biasing the drum to a predetermined position relative to the base, cam means carried at a circumferentially adjustable position on the drum, a cam follower movably supported by the base in alignment with said cam for coaction therewith during rotation of the drum, and means connected to the cam follower for effecting control of the hoist operation.

3. A hoist control mechanism adapted to be driven from the hoist drum so as to have positions correlated to those of the hoist and comprising, in combination, support means, a drum, means for supporting the drum relative to the support means for rotation about a central axis, a shaft, means rotatably supporting the shaft in coaxial relationship to the drum, means for drivingly connecting the shaft to the hoist drum, a pinion cn said shaft and driven thereby, a rotary driven element, means on said drum for rotatably supporting said driven element, intermediate drive means carried by said drum for drivingly connecting said pinion to the rotatable driven elemen stop means secured to said drum at a predetermined position, additional stop means secured to said driven element and disposed for engagement with the first mentioned stop means during rotation of the driven element so that when one stop means engages the other relative rotation between the driven element and drum is arrested and said drum is rotated by force applied through said pinion, means for biasing said drum to a predetermined position relative to the support means, cam means carried by said drum, coacting cam means supported at a fixed position relative to the drum. and means connected to one of said cam means for effecting control of the hoist operation.

. A hoist control mechanism as defined in claim 3 wherein said means for the drum to a predetermined position relative to the support means comprises pulley means rotatably carried by the support means. ilexible means extending over said pulley means and having one end connected to said drum at a predetermined position, and a weight suspended at the other end of said flexible means.

5. A hoistcontrol mechanism adapted to be driven from the hoist drum so as to have positions correlated to those oi the hoist and comprising, in combination, a cam-carrying drum. means for rotatably supporting said cam-carrying drum for movements between predetermined limiting positions. a pair of similarly shaped cams secured to the cam-carrying drum in oppositely disposed and symmetrical relationship to one another, means for biasing the cam-carrying drum to a predetermined position, a cam follower ior each of said cams, driving means including a series of gears for drivingly connecting said gears to said hoist drum for operation at a rate proportional to movements oi' the hoist drum and in a direction dependent upon that of the hoist drum, separated means on one of the gears of said driving means effective during opposite directions of movement oi said one of the gears for drivingly connecting said one of the gears and said cam-carrying drum to eect movement of the cam-carrying drum away from said predetermined position, the separation of said separated means being such that said one oi the gears has a period of rotation relative to the cam-carrying drum during movement of the drum between said limiting positions in each direction, and hoist control means responsive to movements of each of the cams.

6. A hoist control mechanism adapted to be driven from the hoist drum so as to have positions correlated to those of the hoist and comprising, in combination, a cam-carrying drum, means supporting said cam-carrying drum for rotary movement through less than half of one revolution in each direction from a predetermined position. means for biasing the cam-carrying drum to said predetermined position. a pair of hoist speed control cams secured to the cam-carrying drum in axially displaced positions thereon, a pair oi hoist brake control cams secured to the cam-carrying drum in circumferentially displaced relationship to one another, a iirst cam follower means having rollers spaced circumierentially of the camcarrying drum, each of said rollers being aligned axially of the drum with one of the hoist speed control cams. a second cam follower means having a roller aligned axially of the drum with said brake control cams, means biasing one or the other of the rollers of said rst cam follower means toward the path oi' the cam with which it is aligned, the one of said rollers thus biased toward the cam path being dependent upon the direction of operation of the hoist. means for biasing said roller of the second cam follower means toward the path of the brake control cams duringr movement of the hoist in either direction, hoist control means responsive to each of said cam follower means, means driven by the hoist drum. and means effective at a predetermined position of the last mentioned means during movement of the holst in each direction for rotating said camcarrying drum.

'7. A hoist control mechanism adapted to be driven from the hoist drum so as to have positions correlated to those of the hoist and comprising, in combination, a cam-carrying drum,

means supporting said cam rotary movement through less than half of one revolution in each direction from a predetermined position, means for biasing the camcarrying drum to said predetermined position, hoist control cam means secured to the camcarrying drum, cam follower means aligned for coaction with said cam means, means for biasing the cam follower means toward the path of the cam means when the hoist is in operation, hoist control means responsive to movements of said cam follower means. means driven by the hoist drum, and means effective at predetermined positions oi the last mentioned means during movements of the hoist for rotating said cam-carrying drum.

8. In a hoist control mechanism adapted to be driven from the hoist drum so as to have positions correlated to those oi' the hoist. drive means for a rotary control drum comprising a shaft. means rotatably supporting the shaft in coaxial relationship to the drum, means for drivingly connecting the shaft to the hoist drum, a pinion on said shaft and driven thereby, al rotary driven element, means on said drum for rotatabLv supporting said driven element, intermediate drive means carried by said drum for drivingly oonnecting said pinion to the rotatable driven element, stop means mounted at a predetermined position on said drum, additional stop means secured to said driven element and disposed for engagement with the rst mentioned stop means during rotation of the driven element so that when one stop means engages the other relative rotation between the driven element and drum is arrested and said drum is rotated by force applied through said pinion, and means for biasing the control drum to a predetermined position` 9. In a hoist control mechanism adapted to be driven from the hoist-lifting mechanism so as to have positions correlated to those of the hoist, the combination of drive means for a rotary control drum comprising a rotary driven element, means on said drum for rotatably supporting said driven element, means for drivingly connecting the driven element to the hoist-lifting mechanism, a first stop mounted at a predetermined position on said drum. and a second stop secured to said driven element and disposed for engagement with the first stop during rotation of the driven element so that when one stop engages the other relative rotation between the driven element and the drum is arrested and said drum is rotated by force applied through the stops.

l0. 'I'he combination deined in claim 9 wherein said second stop is circumferentialiy adjustable relative to the driven element and engages the nrst stop during rotation of the driven element in one direction, and a third stop is adjustably secured to the driven element for engaging the ilrst stop during rotation of the driven element in the opposite direction.

11. In a hoist control mechanism adapted to be driven from the holst-lifting mechanism so as to have positionscorrelated to those of the holst, the combination of a cam-carrying drum, means supporting said cam-carrying drum for rotary movement through less than halt of one revolution in each direction from a. predetermined position, means for biasing the cam-carrying drum to said predetermined position, a pair o! hoist speed control cams secured to the cam-carrying drum in axially displaced positions thereon, a pair oi hoist brake control cams secured to the cam-carrying drum in circumferentially disdrum tor 13 placed relationship to one another. a ill-st cam follower means having rollers spaced circumferentially of the cam-carrying drum, each oi said rollers being aligned axially of the drum with one ot the hoist speed control cams, a second cam follower means having a roller aligned axially of the drum with said brake control cams, means biasing one or the other of the rollers of said first cam follower means toward the path of the cam with which it is aligned, the one of said rollers thus biased toward the cam path being dependent upon the direction of operation of the hoist, means for biasing said roller oi the second cam follower means toward the path of the brake control cams during movement of lthe hoist in either direction, hoist control means responsive to each of said cam follower means, and resilient means interposed between each said hoist control 14 means and the cam follower to which it is responsive so that each hoist control means can be actuated against the force of said resilient means and independently of the said hoist control mecha- 5 nism.

HENRY H. LOGAN.

REFERENCES CITED The following references are of record in the 10 ille of this vpatent:

UNITED STATES PATENTS Number Name Date 868,604 Glessner Oct. 15, 1907 l5 1,560,057 Hunter Nov. 3, 1925 1,867,452 Hallenbeck July 12, 1932 1,877,171 Hallenbeck Sept. 13, 1932