US2475983A

US2475983A - Hoist

Info

Publication number: US2475983A
Application number: US446378A
Authority: US
Inventors: Robert C Osgood
Original assignee: Joy Manufacturing Co
Current assignee: Joy Manufacturing Co
Priority date: 1942-06-09
Filing date: 1942-06-09
Publication date: 1949-07-12
Anticipated expiration: 1966-07-12

Description

July l2, 1949, R. c. osGooD 2,475,983

July 12, 1949.

Filed June 9, 1942 @ggf R. c. osGoQD 2,475,983

Borsa:

6 Sheets-Sheet 3 wif/f July 12, 1949. R. c. os'GooD 2,475,983

HOIST Filed June 9, 1942 6 Sheets-Sheet 4 R C. OSGOOD July 12, 1949.

HOIST 6 'Sheets-Sheet 5 Filed June 9, 1942 July l2, l949 R. c. osGooD 2,475,983

HoIsT Filed June 9, 1942 e sheets-sheet e combination of parts.

Patented July 12, 1949 UNITED STATES PATENT OFFICE nors'r Robert C. Osgood, Claremont, N. H., assigner to Joy Manufacturing Company, a corporation o! Pennsylvania Application June 9, 1942, Serial No. 446,378

` drum type.

In hoists-of the kind adapted for special applications, such as bomb hoists used in loading bombs into airplanes, it is desirable to provide a pair of cable winding drums having individual driving means and certain types of special controls. Such driving means and controls must be completely foolproof and embody features which result in safety in operation, due to the particular functions involved. In one form there may. be associated with the hoist drums special devices for controlling the Winding of the cables on the drums, and in another form means may be provided for controlling the tensioning of the cables. Further, in both forms above referred to, it is desirable to provide automatic braking devices associated with the drums for controlling the lowering of the load, and for holding the load when drum rotation is discontinued.` It is also desirable in one form to provide a friction safety clutch set under a predetermined load, for preventing substantial overloading of the hoist parts and cables. Also, in one form, the hoist may be constructed in separable parts which may be readily dismantled, thereby to facilitate transportation of the hoist from place toplace, and which may be easily assembled. In one form an automatic limit switch actuated by means driven concurrently with the drum, may be provided to control the drum driving motor, so that the motor may be automatically stopped upon elevation of the load a predetermined distance, thereby to prevent overtravel.

It is an object of the present invention to provide a novel hoist embodying several of the par-- ticular features above mentioned. A further object is to provide an improved cable tensioning device and cable guide for a hoist. A further object is to provide a novel hoist which is completely foolproof and which results in safety in operation. A still further object is to provide an improved hoist having a novel arrangement and How these and other objects are accomplished. and the advantageous features of the invention, will be best understood from the following detailed description wherein preferred and modified illustrative embodiments are set forth, reference for the purpose being had to the accompanying drawings, in which:

Fig. 1 is a plan view of a hoist constructed in accordance with an illustrative embodiment of the invention.

2 Fig. 2 is an end elevational view of the hoist shown in Fig. 1.

Fig. 3 is an enlarged horizontal sec-tional View taken substantially on line 3-3 of Fig. 2.

Fig. 4 is an enlarged horizontal sectional View taken on line 4-4 of Fig. 5.

Fig. 5 is an enlarged vertical sectional view taken substantially on line 5-5 of Fig. 1.

Fig. 6 is a horizontal sectional view taken on line 6-6 of Fig. 5. l

Fig. 7 is an enlarged horizontal sectional view taken on line 1-1 of Fig. 5.

Fig. 8 is an enlarged vertical sectional view taken substantially on line 8-8 oi' Fig. 1, illustrating the cable guiding and tensioning device.

Fig. 9 is a detail vertical sectional view taken substantially on line 9-9 of Fig. 10,'with parts in full.

Fig. 10 is an enlarged detail sectional view taken substantially on line lli-i0 of Fig. 8, with certain parts broken away and others in full to facilitate illustration.

Fig. 11 is an end elevational view, looking oppositely from Fig. 2, illustrating a modified ernbodiment of the invention.

Fig. 12 is an enlarged horizontal sectional view taken substantially on line |2-I2 of Fig. 11.

Fig. 13 is a fragmentary plan view of the left hand unit of the hoist shown in Fig. 11, with parts shown in horizontal section.

Fig. 14 is a fragmentary elevational view of a part of the hoist shown in Fig. 11, illustrating features of the automatic druml control.

In both illustrative embodiments of the invention there is shown a hoist of the double-drum type having driving means individual to each drum, and individual drum control means.

In the embodiment shown in Figs. l to 10, inclusive, a base frame l has journaled thereon

cable winding drums

2 and 3 driven respectively by

motors

4, 4 individual thereto. The base frame is adapted to be secured, as by bolts, to any suitable form of support. The

drums

2 and 3 are arranged in parallel side by side relation and have at one

end transmission housings

5, 5 by which the

lmotors

4, 4 are respectively carried. Associated with the drums are cable guiding and tensioning devices 8, 6, and the cables wound on the drums are designated 1. Since the vdrums and their drives and the cable guiding and tensioning deviceV for each drum are similar in design, a description of those associated with one drum will suffice for both.

As shown in Fig. 3, a horizontal shaft 8 is suitably journaled in

bearings

9, 9 supported within end brackets I attached to the base frame. The drum has hubs II keyed at I2 to the shaft, and also keyed to the shaft is a driving gear I3. The motor 4 has its casing flanged at I4 for attachment, as by bolts, to the transmission housing',

`and xed to the motor powervshaft is a lmotor pinion I5 meshing with a spur gear I6 suitably journaled within the housing. The gear I8 has rotatable therewith and drives a spur pinion I1 meshingwitha spur gear I8. As shown in Fig. 6,

the gear I8 is mounted on a horizontal shaft I9 herein preferably arranged parallel to the motor power shaft and suitably journaled within the housing, and the hub 20 of this gear has screwing with a spur gear 23, the latter being secured to a horizontal shaft 24 suitably journaled. within the housing. Secured to and driven bythe shaft 24 is a spur gear 25 meshing with. the spur gear I3 secured to the drum shaft (Figs. 3, 5 and 6).

, As shown in Figs. '5 and 6, journaled on the hub 20 of the spur gear I8 is a circular plate 26, while secured to the shaft I9 is a circular plate 21 herein arrangedin adjacency to the plate 26, in the manner shown in Fig. 6. The plate 26 is provided at its opposite faces with suitable frictlonal material 28, so that when the gear I8 is moved axially in an outward direction relative to the shaft I8, the gear and plates 26 and 21 are brought into frictional engagement, thereby to brake rotation of the shaft It when the plate 2t is held stationary. When the drum driving motor is reversed to eect unwinding of the hoist cable, if -there is no load on the cable, the gear i8 will be moved in an inward direction against a plate 2e mounted on the shaft I6, and when the gear hub is against this plate the gear and shaft i9 will rotate together while the plate 26 is out of frictional contact with the gear and plate 21.

Thus at this time the brake is automatically re` leased. If there is a load on the hoist cable, there will be a partial release of the braking action, and lowering of the load at a controlled rate, when the motor is rotated by power in a load-lowering direction. The plate 26 is provided at its outer periphery with ratchet teeth 38 with which a spring-pressed pawl or dog 3| is engageable. This pawl slips over the ratchet teeth during rotation of the, drum in cable winding direction, i. e. during raising of a load, and automatically engages the ratchet teeth to hold the plate 26 against rotation in cable unwinding direction, i. e. during tion whenever the motors are stepped and serve to supplement the automatic brakes 26,'21, 28.

Upon starting of the motors these magnetic.v

brakes are automatically released. Theseauto.- matic brakes may, if desired, be under manual control.:

To enable manual operation of the hoisting drums there is provided for each drum a shaft 32 (Fig. 7) suitably journaled within the transmission housing and carrying a gear 33 meshing with the gear I8. The shaft 32 is formed with a vpolygonal portion 34 adapted for engagement by a suitable turning instrument, such as a hand crank, indicated in construction lines in Fig. 2. A detachable cap 35 encloses the polygonal portion 34- of the shaft whenmanual drum rotation is not desired. This manual drum operating means is used only in the event of an emergency, and

during operation of the drum under the control of the manual drum rotating means it is necessary to throw out of operation the automatic magnetic brakes which act on the motor shafts. It is sometimes desirable to detach the motors from the lowering of a load. Thus whenever the motor is stopped and the hoist drum is under load, the brake automatically holds, the load. The load may be lowered simply by reversing the motor and driving the gear 20 in a, direction such as to move it inwardly along the shaft I9, thus permitting slipping of the frictional connection with the pawl-held plate 26. The fact that the load tends to drive the shaft I9 `faster than the motor does the gear 26 explains the automatic prevention of overspeeding during power-lowering of a load.

The drum driving motors are also provided with automatic brakes (not shown) of the conventional magnetic type which are enclosed within the motor housing. These brakes are automatically applied to hold the motor shafts against rotav projections 38 (see Fig. 3) integral with the drum v brackets I0, I0. These brackets are swivelly mounted to swing about axes coincidentwith the axis of drum rotation-and are connected together by a tie bolt 39. The brackets have split caps 36' adjustable by screws 31' for clamping the brackets I in `adjusted position. Arranged parallel to the tie bolt and journaled on the brackets 36 is a screw shaft with which a traveling nut 6I is threadedly engaged. vThis nut is integral with a guide block 62 guided for rectilinear movement on the tie bolt 39 and has a guide opening 43 through which the (able passes. A spur gear M keyed to the drum shaft 8 meshes with a spur gear 65 journaled on a stub shaft 46 secured to the adjacent end bracket. The gear 45 meshes with and drives a gear 41 fixed to the Vscrew shaft 40. Thus when the drum is driven, the guide block 42 is moved concurrently across the drum to effect even laying of the cable on the drum.

.Associated with the cable guide is a cable tensioning device comprising a pair of rubber-faced

rollers

48 and 49 mounted on shafts 58 suitably journaled on the end brackets 36. The roller 48 is driven from the drum shaft through

spur gears

5 I, 52, 53, the latter being fixed to the roller shaft. The other roller 49 is adjustable toward and from the power driven roller by means of an adjusting screw 5t. To permit adjustment of the roller 49 with respect to the power driven roller, the shaft of the roller 49 is journaled at its ends within slide blocks mounted in guideways 56 on the brackets. The cable passes between these rollers and since one of these rollers is power driven at the same speed 'as thecable winding speed of the drum, the cable gripped by lto enable adjustment of the roller speed to correspond exactly to the cable winding speed ol' the drum. Thus the cable is always maintained under tension between the roller and the drum. If desired both of the rollers may be power driven, in lieu of the single one disclosed, and both rollers may be adjustably mounted. The guide brackets 3l are swingable into different angular positions about their pivotal mountings -at 31 to permit guiding of the cables even when the latter are extended in different angular directions within predetermined limits with respect to the drums, as indicated in dotted lines in Fig. 2.

In the modified embodiment of the invention shown in Figs. 1l to 14, inclusive, the hoist disclosed is generally similar to that above described. In this instance, however, certain important differences are present. In this construction a base frame 99 is adapted to be secured to any suitable support and has journaled thereon cable winding drums Il and 32, similar to the

drums

2 and 3. 'I'hese drums are journaled in parallel relation on the frame, but, in this instance, the axis of rotation of the drum 3| is arranged in a position on the frame slightly lower than theaxis of rotation of the drum l2. Such drum arrangement enables the cables on the drums to be extended in various directions with respect thereto, and, in one position, the cable on the drum I! may be extended laterally above the drum 3|, as indicated in dotted lines in Fig. 11. As in the other embodiment of the invention, the motors 33 are detachably mounted on transmission housings 3l, but in this instance the housing 64 is detachably secured, as by bolts 65, to the base frame; and the base frame is made in two parts secured together at 66 at the vertical center of the hoist,

as by bolts 61. Thus the hoist is separable into at least four major portions, two of the'portions carrying the drums and the lother two portions carrying the motors and transmissions. The separable frame parts and the transmission housings carrying the motors` are provided with

handles

39 and 99 whereby the hoist parts when separated maybe readily transported from place to place.

The driving means for the drums Bi and 32 are similar and therefore a description of one will suillce for both. As shown in Fig. 12, the motor power shaft has fixed thereto a spur motor pinion 1l meshing with a spur gear 1I, and rotatable with and driven by the gear 1i is a spur pinion 12 meshing with a spur gear 13. The gear 13 drives a shaft 14 suitably journaled within the housing, and secured to and driven by this shaft is a spur gear 1l meshing with a spur gear 13. The gear 18 connected by a friction clutch 11 to a shaft 13 likewise suitably Journaled in the housing, and secured to and driven by this shaft is a gear 19 meshing with a spur gear 39 connected as later explained to the drum shaft 3l. An automatic clutch and braking device, generally designated 92, similar to that above described in connection with the gear Il, is associated with the gear 13. 'I'he clutch 11 is set to slip at a predetermined load by means of a setting device I3 of the screw and nut type, and this clutch .is yieldingly held applied by means of a spring plate 34. In the event the drum for any reason becomes overloaded, the clutch 11 automatically slips, to prevent breakage of the hoist parts and cable. This overload clutch is necessary in a hoist of this character since, without its provi sion, the hoist parts andcables might break due to overload, in the event the load is suddenly placed on the cable. As shown in Fig. 12, the hub 3l of the gear 30 is journaled in a bearing 39 supported within the housing, and secured within a bore I1 in the gear hub is a cylindric portion 39 of a stub shaft 39 journaled within a bearing 99 likewise suitably supported within the housing. The shaft 3| ls splined at 9| within the gear hub, so that when the housing is detached from the frame the gear hub may be readily slid from engagement with the drum shaft.

Associated with each drum is an automatic control device, generally designated 92, comprising a screw shaft 93 suitably journaled on the end brackets by which the hoist drum is supported. This screw shaft is driven from the drum through a spur gear 94 secured to the drum and meshing with a spur gear 9B fixed to the screw shaft. Arranged parallel with the screw shaft and likewise supported within the4 drum brackets, is a guide rod 96. A traveling nut 91 is threadedly engaged with the screw shaft and has guided engagement with the guide rod, so that when the screw shaft is rotated, the nut may move across the drum. Mounted'- on the adjacent drum I bracket is a switch 99 having an .operating plunger 99, and this plunger is engageable by the traveling nut 91 to eifect stopping of the drum driving motor ,at a predetermined time. The plungers are adjustable to permit alteration of the times when the motors are stopped. In this instance the hoist driving motor is automatically stopped when the load carried by the hoist cable has been elevated a predetermined distance.

In hoists of the character disclosed, the drum driving motors, which are herein preferably of the reversible electric type, are controlled by push-'button operated switches so that the drums may be concurrently operated or may .be operated independently of each other. These switches have conventional push-button controls which must be manually heldin during operation of the motors and which automatically move into a position to effect stopping of-the motors when released by the operator. Such push-button operated switches are necessary in a bomb hoist since it is not only desirable to effect winding in or paying out of both cables concurrently, but also` at times to operate one drum independently of the other. Such manner of control is particularly necessary during the loading of a bomb within the bomb rack of an airplane when the bomb is not only raised into a position near the level of the rack but is also turned slightly about its longitudinal axis to fasten the bomb within the rack. It is accordingly evident that the pushbuttons for operating the switches must be manually held in to effect running of the motors and the motors are automatically stopped whenever the push-buttonsl are released.

The general mode of operation of the improved hoist is as follows. In the embodiment shown in Figs. l to l0, inclusive, the hoist cables 1 are extended upwardly from the adjacent sides of the cdrums, in the manner shown in full lines in Fig. 2, and the cables pass through the guide openings inthe traveling guide blocks of the cable tenl sioning and guiding devices 6. The motors 4 may ,then be started and the drums are driven in a direction to wind in the cables through the spur '$1.0 gearing l5, i9, l1, I8, shaft I9 and spur gearing :22, 23, 25 and I3, and as the cables are wound in :the pawls 3l slip over the ratchet teeth 30 on the circular plates 2B and the brake associated with .the gear i9 is automatically rendered ineffective.

.fffWhen the motors are stopped, the pawls engage the -ratchet teeth to hold the plates 2B against rotation, and since the plates 26 have4 been clamped between the plates 21 and the gears I8 during hoisting, the drums will be held against reverse rotation. By reversing the motor, the drum load may be lowered and atthat time the automatic brake is so controlled as to permit rotation of the drums in cable unwinding direction. The drums may .be also manually lowered through the hand cranks attached to the shafts 32 of the manual drum rotating means. By individually controlling the

motors

4, 4, the drums may be individually driven. The cable guiding and tensioning devices B, 6 act to maintain the cables under tension as they are wound onto the drums, and in the event the cables are directed in different angular positions with respect to the drums, as indicated in dotted lines in Fig. 2, the devices 6 may swing abouttheir pivotal mountings with respect to the drums. The mode of operation of the embodiment shown in Figs. 11 to 14, inclusive, is essentially the same as that above described. In this instance, however, in addition to the automatic brake, there is associated with the drum driving gearing the overload clutch 'l1 which slips automatically upon overload to prevent breakage. By the particular drum attachment of this embodiment, the cables on the drums maybe extended in various directions with respect to the drums. By releasing the bolts which hold the separable sections of the winding direction, i. e. during lowering of a load, i

and is automatically connected (though the pawls prevent free winding rotation) upon vdrum rotation in cable winding direction and holds the associated drum automatically-'when power is out off the motor.

As a result of this invention, it will be noted that a novel hoist is provided having improved driving and control. means for the cable winding drums thereof whereby an extremely foolproof and safe hoist is obtained. By the provision of the novel arrangement disclosed, the hoist is also rendered compact and readily portable. Further, by the provision of the particular driving means i'or the drums, the drums are driven in an improved manner, and byassociating the automatic brake and ratchet device with'the drum driving gearing, the drums are automatically controlled in a novel manner. It will also Ibe evident that by the provision of the cable guiding and tensioning device, mounted in the manner disclosed,-

guiding and tensioning of the cableis improved.

Also, by forming the hoistof readily separable` parts, the hoist may be quickly dismantled and easily transported from place to place. Further, in the modified embodiment, the automatic limit may assume in practice, it will be understood that these embodiments of the same are shown for purposes of illustration and that the invention may be further modiiied and embodied without departing from its spirit or the scope of the appended claims. v

What I claim as new and desire to secure by Letters Patent is:

1. In a hoist, a frarne,l a winding drum journaled on said frame and having a cable wound thereon, means for driving said drum, and a cable guiding andl tensioning device pivotally mounted on said frame for adjustment relative thereto for guiding the cable in various angular directions with respect to said drum and for maintaining the cable under tension irrespective of its guided position, said guiding and tensioning device embodying cable engaging means driven through said drum driving means for feeding the cable with respect to said drum at a speed equal to the cable winding or unwinding speed.

2. In a hoist, a frame, a winding drum journaled on said frame and .having a cable wound thereon, means for driving said drum, and a cable guiding and tensioning device pivotally mounted on said frame for adjustment relative thereto for guiding the cable in various angular directions with respect to said drum and for maintaining said cable under tension irrespective of its guided position, said cable guiding and tensioning device being mounted on said frame to swing with respect to said drum about an axis coincident with the axis of drum rotation and embodying cable engaging means driven through said drum driving means for feeding the cable with respect to said drum at a speed equal to the cable winding or unwinding speed.

3.,In a hoist, a frame, a drum journaled on said frameand having a cable wound thereon, means for driving said drum, a cable guide pivotally mounted Yon said frame for guiding the cable in various angular directions with respect to said drum and having a cable guiding clement, and means associated with said cable guide and. mounted to swing therewith for automatically tensioning the cable, said guiding element being mounted for rectilinear movement in a direction lengthwise of said drum relative to said cable vtensioning means, and means for moving said guiding element rectilinearly as aforesaid.

f 4. In a hoist, a cable winding drum, drum driving means, and means associated with said drum for automatically tensioning the cable as it is wound on or unwound from said drum comprising apair of parallel cable engaging rollers coextensive with said drum and between which the cable passes and along which the cable moves as it is wound in or unwound, said rollers having rubber facings for frictionally engaging the cable, roller driving means operatively connected with one of said. rollers for driving the same concurrently with said drum at a speed to feed the cable between said rollers towards or from said drum switch, actuated by means driven concurrently at the -same speed as the cable Winding or unwinding speed of said drum, and means for relatively adjusting said rollers for compressing the rubber facings thereof to vary the roller contact with the cable thereby to obtain the proper cable tension.

5. In a hoist, a frame, a cable winding drum Journaled on said frame, drum driving means, and cable tensioning means pivotally mounted on said frame to swing with respect to said drum about an axis coincident with the axis of drum rotation vfor tensioning the cable, said tensioning 9 means including. cooperating tensioning elements coextensive with said drum and between which the cable passes.

ROBERT C. OSGOOD.

REFERENCES CITED The folluwing references are of record in the le of this patent:

UNITED STATES m'mms Number I Name Date 160,308 Crowthers et al. Mar. 2, 1875 342,880 Scarborough June' 1, 1386 402.688 Schultz May 7, 1389 456,753 Gibbins July 28, 1891 528,507 Sharp Nov. 6, 1894 853,929 Hunt -1 Oct. 23, 1906 959,521 Sessions May 31, 1910 1,020,014 Armington Mar. 12,. 1912 1,131,980 Norris. May 2, 1916 `Number Number 2@ 765,387

France Mar. 26, 1934 Certificate of Correction Patent No. 2,475,983 July 12, 1949 ROBERT C. OSGOOD It is hereby certified that errors appear in the printed specification of the above numbered patent requirlng correction as follows:

Column 2, line 51, for the Word device read devices; column 7, line 28, for attachment read arrangement;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Ofce.

Signed and sealed this 13th day of December, A. D. 1949.

THOMAS F. MURPHY,

Assistant Oomm'issz'oner of Patents.