US2570833A

US2570833A - Electric chain hoist

Info

Publication number: US2570833A
Application number: US738430A
Authority: US
Inventors: Irving R Metcalf; George E Bock
Original assignee: Whiting Corp
Current assignee: Whiting Corp
Priority date: 1947-03-31
Filing date: 1947-03-31
Publication date: 1951-10-09
Anticipated expiration: 1968-10-09

Description

'7 Sheets-Sheet l Filed Maoh 31, 1947 w O @M5 @ME www Get. 9, 1951 1. R. METcALF ET A1.

ELECTRIC CHAIN HoIsT 7 Sheets-Sheet 2 Filed March 3l, 1947 Oct. 9, 1951 A|. R. METcALF ET A1.

ELECTRIC CHAIN HoIsT 7 Sheets-Sheet 3 Filed rch 1, 1947 Oct- 9, 1951 l. R. METcALF ETAL 2,570,833

ELECTRIC CHAIN HoIsT Filed March 3l, 1947 '7 Sheets-Sheet 4 George OC 9, 1951 l. R. METAL ET AL 2,570,833

ELECTRIC CHAIN HOIST I Filed March 5l, 1947 7 Sheets-Sheet 5 M l I Q l it Q a w1 l m. m-- M l l! @y www 0d 9, 1951 l. R. METC'ALF ET AL 2,570,833'

ELECTRIC CHAIN HoIsT Filed March 51, 1947 7 sheets-sheet e Oct. 9, 1951 l. R. MEfrcALF ET Al.

Patented Oct. 9, 1951 .Y .UNlTEDsw-TATES 'PATENT OFFICE 4 Ill., assignorsY to WhitingCorporation, Harvey,

Ill.,'a corporationV of Illinois A Application March 31, 1947, ser'ia'no, .73s,43f7

1 VThe present invention, relates generally to electric chain hoists. More particularly the invention .relates to that type. oihoist which is adapted to .of the motor byway ofpeed reducing gearing; .(4). aroller chain which has one end thereof .anchored to the frame.. at a p oint Vadjacent the sprocket and its otheryend.;pr.ovided with ajhook for attachment to the load to be hoisted and is .trained aroundY thesprocket to the enel that when the sprocket is drivenrin one direction thehool is raised andv When..the -sprocket is driven in the opposite directiOnthe hook is lowered; (5)v a reversing switch which serves to control the supply of kcurrent tortheelectric `motor; (6) a brake which operates to lock the sprocket lagainst, rotation when the reversing switch is in its neutral or off position; and (7) 4a manually operable control mechanism which is operatively connected to the switch and the brake,l comprissa centrally fulcrumed lever and operates when tilted in either direction from anormal horizontal position to shift the switchinto one of its operating positions Y'and at the same time release the brake.

One object of the invention is to providean Yelectric chain hoist of this typewhich isan improvement upon, and has certain inherent advantages over, previously designed hoists of the same general character and is characterized by a novel arrangement of parts whereby compactness, high efficiency and lightness of Yweight are obtained.

. Another object of the invention is to provide an electric chain hoist of the type under consideration in which the electric motor is disposed,

on one side of the frame and the gearing, the reversing switch, the brake and the manually operable control mechanism are all mounted on the other side of the frame in order that the hoist as a whole when suspended by the hook on the frame is properly balanced without the necessity of employing a counterweight.

Another object of the invention is to provide v11 claims. (c1. zar-16s) sprocketis connected for drive by the armature shaft of the motor 4consists of a first wormand wornwheel and a second worm land worm wheel andis self locking or irreversible in order that the load on the chain hook remains stationary in the event of failure of the`V brake or manual release of the Vbrake during stoppage or interruption in the supply of electric current to the motor. Y Another object of 'the'invention is' to provide anv electric chain hoistin which the brakeis arranged and constructed in a novel manner and the brake and reversing switch are disposedin close proximity to, but outwards of, the housing for the gearing between the armature shaft and thesprocket and are housed within a readily removable sheet metal shell.

Another object offtheinvention is to provide an electric chain hoist Vof the last mentioned charlacter in which the manually operable control mechanism is constructed and arranged in a novel manner and is for the`rnostpa`rt housed or, disposed within the sheet-l metal shell.

Another Yobject of the'invention is to provide an electric chain hoist of the aforementioned type which, if desired and without rerigging o r rearrangement of parts, is capable of being supported from above by the hook on the chain and when so supported is adapted to travel up and down the chain and support the load by way of the hook on the frame.

A further object of the invention is the provision in connection with an electric chain hoist of the last mentioned character, of a roller which is rotatably wmounteolon the frame adjacent'l Vthe point where the chainis anchored and serves when the hoist is used while supported onthe hook on the chain to guide the portion of the v.chain which is in loop form and extends between the anchored chain end and the sprocket.

A still further object of ythe invention is to provide an electric chain hoist which is generally of new and improved construction, effectively and efciently fullls its intended purpose and, due

to its design and construction, occupies butY a .tured or fabricated at a comparatively low cost.

comparatively small space and may be manufacjr, Qther objects of the invention and the various advantages and `characteristics of the present electric'ch'ain hoist willbe apparent from aconsiderationofthe following detailed description.V

The invention consists Ain the several novel features'which are hereinafterI sety forth andare an electric chain hoist of the aforementioned type T:

and character in which the gearing whereby the' f'inore particularly clusion hereof.

defined by claims ,at the conln'thedrawings which accompany andforma part of this specication or disclosure and in which like numerals of reference denote corresponding parts throughout the several views:

Figure 1 is an end view of an electric chain hoist embodying the invention, the view being toward or in the direction of the end that is opposite the electric motor and has the readily removable sheet metal shell for housing the rever-sing switch, the brake and the manually operable control mechanism;

Figure 2 is a vertical transverse section illus-,- trating in detail the construction and design of the hook equipped frame;

Figure 3 is a vertical longitudinal section;

Figure 4 is a vertical transverse sectionon the line 4-4 of Figure 3;

Figure 5 is a side elevation, certain parts bing broken away and other parts being 'shown in section for purposes of illustration;

Figure 6 is a vertical transverse section taken on the kline 6 6 of Figure 5 and illustrating in AJdetail the construction, design and arrangement '"oi the gearing for driving the sprocket from the electric motor;

Figure 7 is an enlarged vertical transverse section taken on the line 'I-'I of Figure 5 and Yshowing the construction of the brake for locking the sprocket against rotation when the reversing ,Switch is in its neutral or off position;

Figure 8 is an enlarged vertical transverse section taken on the line 8;-8 of Figure 5 and illustrating the lconstruction and design ci the Ina-nially operable control mechanism;

, Figure 9 is a vertical longitudinal section on the lifne 9-9 of Figure S;

Figure 10 is a section taken on the line IIl-IU of Figure '7 and showing in detail the construction and design of the reversing switch;

. k Figures ll l2 are vertical transverse sec- "ti'ons taken respectively on the lines II-II and I2-'-I2 of Figure 10; and

Figure 13 is a vertical transverse section showing the hoist in its inverted position wherein it is supported by the hook on the chain.

'I he electric chain hoist which is shown in the drawings constitutes the'preferred form or embodiment of the invention. It is adapted, as well 'understood in the to be lnmg or 4suspended from an overhead support'and serves as an instrumentality or medium for hoisting a load. As

Vvits main or principal partsthe hoist comprises a frame I5, an electric motor I6, a sprocket V, a` roller chain I8, a reversing switch I9, a brake "2'0, and a manually operable control mechanism ,2| for the switch and brake.

The frame I5 serves as a supporting structure `'for the other parts of the hoist and has asso- "arcuate wall 24 extends through an arc of approximate1y`280 and is arranged so that the ends s thereof are at the bottom portion of the frame "I5, The lower arcuate wall 25 extends throughout an arc of approximately 135 and is located between the'ends of the upper arcuate wall 24. has a materially less radius than the upper arcuate wall and partially surrounds, and serves as a chain guide instrumentality fonthe sprocket I'I. Associated with the frame I'5 is an upstanding hook 21 and this is adapted for attachment to the overhead support (not shown) and serves to suspend .the hoist from the support. The shank of the hook extends through, and is rotatably mounted in, a tubular boss 28 which is formed integrally with, and depends from, the upper central portion of the upper arcuate wall 24 of the frame. A nut 29 is mounted on the lower end of the shank and coacts with a shoulder 30 to hold the hook 2'I against vertical displacement with respect to the frame I5 while at the same time permitting the hook to swivel an anti-friction thrust type bearing 3| is interposed between the nut 29 and the lower end of the boss 28, as "shown in Figure 3. The hook 21 is so positioned with respect t'o the center of mass of the hoist that when Vthe hoist is suspended by the hook it is truly balanced both horizontally and longitudinally, as shown in the drawings.

The housing 22 is located on the side of the frame I5 that has the enlargement '26. Preferably it is in the form of a one-piece casting and consists of a vertically extending inner end wall 32, a vertically extending outer end wall 33 and a continuous `side Wall 34. The inner end wall Z2 elliptical and iits flatly against the Vertically extending wall 23 of the frame I5 When the hoist is in its normal or operative position wherein it is suspended by the hook 21 the major axis of the inner end wall 32 extends horizontally. l'iie 'central and lower portions of the inner end wall have formed therein a diagonally ex'- tendin'g opening-35 and this is Vshaped conformably to, and has disposed therein, the enlargement 26 on the vertically extending Wall 23 on the frame I5. Bolts 36 extend through the

walls

23 and 32 and serve to secure the housing 22 in xed relation with the frame I5. The vertically extendingouter end wall is spaced outwards from the inner end wall 32 and defines with the latter and the continuous side wall 34 a compartnient 37 which is partially filled 'with any suitable lubricant and has disposed therein certain hereinafter described gearing for driving the sprocket lI I from the electric motor I6. The continuous side wall V34 extends between, and is connected to, the two

end walls

32 and 33 and Vis shaped, so far as cross section is concerned, as showh'fin Figure 6. Lubricant is introduced into the compartment 37 by way of a screw threaded hole 38 which is formed in the side Wall 34 of the Vhousing 32 and is normally closed by a screw plug 39. A horizontally and outwardly extending webY 4E is connected to'one side of the housing side wall 34 and a pair of spaced apart upwardly and outwardly extending webs 4I isconnected to the other side of the side wall 34. The outer edges of these three webs are straight and, as shownin Figure 6, are aligned with the adjacent portions of the edge of the elliptical inner end wall V32 of the vhousing 22.

The electric motor I5 is of the reversible variety. It is located adjacent the side of the frame I5 that has the

arcuate walls

24 and 25 and consists of a cup-shaped casing 42, eld windings '43 andan armature (not shown). The side wall of the casing is aligned with, and has the same radius as, the upper arcuate wall 24. It is connected to the last mentioned wall by -way of a tongue and groove pilot variety connection 44. Bolts (not shown) serve removably to connect the casing vo f the reversible motor I6 to the arcuate wall 24. The leld windings of the motor aresuitably mounted within the side wall of the casing 42 and surround the armature. 'The latter is mounted on one end of a horizontally extending shaft 45.

The central portion of the shaft extends through a hole 46 in the central portion of the vertically extending wall 23V of the hoist frame I and is rotatably supported age of lubricant past the hole 46 and the ball bearing 41. The other end of the shaft 45, i. e.,

' the end that is opposite that to which is applied the armature of the electric motor I6, extends through a hole 49 in the outer end wall 33. of "the housing 22 and is rotatably supported by way of a ball bearing 5U, the outer race of which ts snugly within the hole 49. A lubricant seal 5I is disposed outwards of therball bearing 50.

vand serves to prevent lubricant from flowing 'jfrorn the compartment 31 through the hole 49.

Asl hereinafter described the motor IIB is controlled by the reversing switch I9.

The sprocket'I1 is located beneath Qne'si'ole of the armature shaft 45.v It is -partially surrounded by the lower arcuate wall of the frame I5 and is keyed or otherwise 4xedly vsecured to one end of a horizontally extending Shaft 52. Such shaft is in parallel relation with the armature shaft 45 and is disposed for the rmost part in the compartment 31 withinthe housing 22. The end of the shaft 52 to which is applied the sprocket I1 extends through a circular hole 53 in the lower portion of the vertically extending wall 23 of the frame I5 and is rotatably supported by way of a ball bearing 54, the outer race of which fits snugly within the hole. A lubricant seal 55 is-located in the outer end of the hole 53 and serves to prevent leakage of lubricant past the ball bearing'54.: The other Vend of the shaft 52 is rotatably supported by way of a ball bearing '56, the outer race of which fits snugly within a circular recess 51` in vthe lower portion of the outer end Wall 33 of the housing 22. The sprocket I1 is driven from the electric motor I6 by way of gearing. Thelatter is disposed wholly within. the compartment 31 in the housing 22 and consists of a worm 58, a worm wheel 59, a shaft 63, a vworm 3| and a worm wheel 62. The worm 58 is formed integrally with that portion of the armature shaft which extends between the ball bearings 41 and 58, meshes with, and serves to drive, the worm wheel The latter is keyed, splined or otherwise fixedly secured to Vone end of the shaft 6B. :The latter, as shown in Figure 6, extends diagonally and has the upper end thereof supported rotatably by way of a ball bearing 63 and its lower end rotatably supported by way of a ball bearing 64. The worm gear 59 is applied to the upper end of the diagonally extending shaft IIl.V The Aouter race of the ball bearing 63 fits snugly within a'circular hole 65 in the topportion, of the @housing side wall 34 and the outer race fof they ball bearing 64 fits snugly within a circular hole '66 in the lower portion of the housing side wall. The hole 65 is covered by a removable cap 61 and the hole 66 is covered by a removable cap 6 8. The worm 6I is formed integrally with the lower end of the diagonally extending shaft 60 and meshes with, and serves to drive, the worm wheel 62. vs plines to thecentral portion of the horizontally extending `shaft 52 and is held Y, against, lateraleA displacement by way of a pair of sleeves 69.

The latter is connected byr way of .jy 6 Such sleeves are located on opposite sides of the worm Wheel 62 and have the outer ends thereof in abutment with the inner races of the two rball bearings which .serve rotatably to support the shaft 52. When the motor I6 is driven in one direction the aforementioned gearing consisting of the worm 58, the worm wheel 59, the shaft '60, thek worm 6I and the Worm wheel 62 is driven in one direction, and when the electric motor, is driven in the reverse direction the gearing is reversely driven. The angle of r the helix of the worm 6I is such that the gear- 10ne end of the chain is provided with aswivel type load receiving hook 1li. The other lend is ypivotally connected to a horizontally extending anchor post 1I by way of a pair of links 12.. :As shown in Figure 4, the post 1I is located in side by side relation with the sprocket I1 and is connected to a boss on the lower portion of the vertically extending wall 23 of the frame I5. When the sprocket I1 is driven in one direction the hook 10 is raised and when the sprocket is reversely driven the hook is lowered. It is contemplated that in most instances the hoist vwill be supported from above by way of the upstanding hook 21 on the frame I5. When so supported the portion of the chain I8 that is between the sprocket I1 and the anchor post 1I hangs downwards in the form of aloop, as shown in Figure 2.

When the hook is lowered the loop decreases in length and when the hook is raised the loop increases in length. It is also contemplated that in certain instances the hoist, instead of being supported from above by the upstanding hook 21 on the frame I5, will be supported by the chain hook 10, as shown in Figure 13. When so supported the hook 21 is adapted to be connected to the load and Ain connection with operati-on of the motor the hoist travels up the chain or down the chain, depending upon the direction of drive ofthe motor. In order to guide that portion of the chain that extends between the anchor post and the sprocket to and from the sprocket when the hoist is in, what may be termed, its inverted position wherein it is supported from above by the chain hook 10, a roller 13 is provided. This roller is substantially the same in diameter as the sprocket and is mounted for free rotation on the anchor post 1I. It is disposedin the same plane as the sprocket I1 and is straddled by the links 12 which serve, as heretofore pointed out, to connect one end of the chain I1 to the anchor post. A cap screw 14 is applied to the outer end of the anchor post 1I and serves tohold the two links 12 and the roller 13 `against outward displacement with respect to the anchor post. When the hoist is manipulated into itsrinverted position and supported from above by the chain hook the links 12 automatically swing downwards into the position Figures 2 and 13, the sprocket I1 is so positioned or arranged that the portion of the chain thatis between the sprocket andthe chain hook isvin V alignment with the shank of the hook 21. A

stripper 15 is xedly connected by way of lbolts T6 to the bottom or lower portion of the vertijcally extending wall 23 of the frame T5. Itis so Varranged that ywhen the hoist is suspended from above by the hook 2-'l'it underlies the Sprocket l||. Y The reversing switch i9 is disposed at one side "serves to control the supply of current to the electric motor I6 and consists of a plurality of rotary contacts 1l, a rectilinear series of equi- 'distantly spaced apart contact lingers :18 and an -opposed rectilinear series of equidistantly spaced apart fingers '59. The rotary contacts TI are mounted on a 'horizontally extending rock shaft '89, as best shown in Figures 10 and l1. Such shaft is disposed in parallel relation with the armature shaft 45 of the electric motor 'I6 and is `supported rotatably by three spaced apart upstanding stamped metal plates 8|, 82 and f83. v'Ihe latter extend transversely of the V"armature Shaft and have aligned circular Vholes 'in the 'lower portions thereof. A horizontally Y.extendlng tube 84 extends through these holes 'and-'is xedly secured to `the hole dening portions of the plates by drive or press fits in order that the plates and the tube are in rigid relation. The central portion of the tube nts against the adjacent portion of the side wall 34 'of the lhousing 22 and is clamped in place by way of a clamp plate 85, one end of which is bent into 'semicircular form and partially surrounds'the central portion of the tube 84 and the other end of which is connected to a lug 86 on the housing lside wall 34 by way of a clamp bolti8'l. VWhen the clamp bolt is loosened so as to release clamp- `ing pressure on the tube the plates 8|, V82 'and -83 may be swung downwards away from the :housing side wall into a position wherein the reversing switch is readily accessible for inspection or assembly purposes. The normal position of the plates 8| and 82 is adjacent the housing side wall. The inner end of the tube 84 Yextends through a slot 38 in the elliptical inner'end wall 32 of the housing 22 and terminates adjacent one end of the lower arcuate wall 25 of the vframe I5. The other or outer end of the tube v'dil Aprojects a comparatively small distance beyond or outwards of the outer end wall 33 of the housing 22. The plate 8| is located adjacent the elliptical inner end wall 32 of the housing and the plate 82 is located adjacent the outer'end wall 33 Y vof'the housing. The third plate, i. e., plate 83, is located directly inwards of the outer end of the tube 84. The upper portions of the three plates are provided with aligned .bearings 89 in which the rock shaft 89 is journalled. .Suitable and properly located collars on the rock shaft serve to hold the latter against axial displacement `with respect to the plates .9| 82 and 83. The rotatable contacts 'Il of the reversing switch are mounted on the portion of the rock shaft that is between the plates 8| and 82. The contact lingers 18 are located on the inner side of the rock shaft andthe lower ends thereof are suitably connected to a bar 99 of insulating material. The other contact'ngers, i. e., the contact fingers '19, are located adjacent the outer side of therock shaft and have the lower ends thereof suitably secured to a bar 9| of insulating material. The bars 99 and 9| are disposed in opposed and parallel relation and have the ends thereof secured in clamped relation against the central portions of the side edges of the'p1ates"8| Y.and 82 by 'way of bolts 92. The arrangement of the rotary contacts 'Il is such that when the rock shaft 89 is rocked in one direction from a `neu- `vof the lhousing 22 and underlies the web 49. It

tral position the motor is driven in one direction 'fand whenitherock `shaft'is rocked in Lthe opposite direction from a neutral position the moto-r is driven in the opposite direction. kCurrent under control of the reversing switch 4I9 is supplied -to the electric'motor i6 by way of a plurality of conductors (not shown). VSuch conductors lead *to the reversing switch and extend through a sheath 93, one end of which is connected by an elbow 94 to the elliptical inner end wall 32 of the'housing. When the rock shaft is in its neutral or so-called off position no current is supplied to the motor. The rock'shaft is urged into its vneutral `or-oif positioniby'way of a device consisting'of 4a helical spring 95 and an arm 96. The spring encircles or surrounds fa vbushing 9'! which is connected to the arm. The ends'of the spring 95-projectfup wards in spaced apart relation -and 'have the upper ends thereof disposed in notches 98 in the Vsides 'of'a lug'99. The latter is formed integrally with and extends outwards at right angles to the upper end of the plate B2. The spring 95'i-is loaded so that the ends thereof press inwards against the sides ofthe lug :99. The-armes is xedlyconnectedto, `and extends radially from, the central Yportion of the rock shaft and isprovided at its outer end with a right angle lug |99 which underlies the lug 99 and is disposed between the ends of the spring 95. When the rock shaft V99 `is rocked in 'one direction the lug Yequipped'arm 96fdistends or shifts laterally'one out of engagement with the contact fingers, as

'shown :in Figure '11.

The plate 63 which, -to gether with 4the Yplates 8| and '82, serves to sup- :port the reversing -switch r| 9 has an upwardly extending extension |-9l which is disposed a comparatively small .distance in front of the'verti- Vcally-extending outer end wall 33 of the housing 22. As shown in Figure 8 the two corner portions of this extension are provided with slots |92 through which normally extendv the outer 'ends of a pair of Ahorizontally extending studs |93. The inner Y ends of the studs are connected to the housing end wall 33 and the outer end of the studs are providedwith fixed collars |94 and nuts |95. The collars abut against the inner surface of the extension Il of the vpla-te 83 and the nuts V|95 fit against the outer surface of said extension and are adapted when Vtightened to clamp the notched corner portions of the extension against the collars |94. The notches are'so arranged and shaped that when the nuts |95 are released after loosening of the clamp bolt 85 the Lplate 83 is free `so that it may be swung laterally and `downwards with the plates 8i and 82 in order .to provide access to the reversing switch.

The brake 29 serves rimmediately to stop the electric vmotor I6 when the reversing switch is shifted to its neutral or olf position and when operative locksrthe sprocketl'l against rotation in either direction. It is disposed outwards of the vertically extending outer end wall 33 of the housing 22 and comprises a cup shaped drum |96, a brake disc |91 and a brake band |98. The drum |96 is in the form of a sheet metal stamping and consists of a vertically extending circular end wall |99 and a cylindrical side wall ||0. The end wall is Vdisposed in concentric relation wrththe armature shaft -45 and has `a central hole through which the exposed outer endof the armature shaftextends. It fits flatly against the housing end wall 33 and is xedly secured to the latter by way of bolts I I I. Asbest shown Figure the drum |06 is disposed directly inwards of the extension |0I of the plate 83. The cylnidrical side wall IIO of the drum |00 is connected to the margin of, and projects outwards from, the end wall |09. It surrounds the brake disci I 0'I and has adjacent the outer end of the rock shaft 80 a cutout I|2. The brake disc |01 is keyed or otherwise xedly secured to the outer exposed end of the armature shaft and is disposed in concentric relation with, and spaced a smalldistance from, the sidewall ||0 of the cup shaped drum 106. The brake band |08 surrounds the brake disc |01 and is arranged so that the ends thereof are disposed adjacent the cutout I'I2 inthe cylindrical side wall of the drum. As shown in Figure 7 the ends of the brake band are doubled back so as to extend around the intermediate connecting parts of a pair of spaced apart U-shaped brackets II3. Such brackets are welded or otherwise rigidly connected to the doubled back ends of the brake band. They are spaced apart a distance less than the length of the cutout I l2 and carry h0rizontally extending pins H4. The ends of the pins extend through circular holes in therside legs of the brackets II3. Two pairs of coacting toggle links IIE serve operatively to connect the brackets |13. The inner ends of the links H5 are pivotally connected together by way of a pin IIS and the outer ends of the links have holes through which the ends of the pins IIfl extend loosely'. The toggle links II5'are at all times disposed at an angle less thanV 180. They are positioned so that the inner ends thereof are away from the brake disc I0'I. A pair of helical tension springs III serve to urge together the brackets II3 inorder to cause the brake band I0Y8'to contract around the brake disc |01. The springs are located outwards of the toggle links I I5 and have the ends thereof applied to the ends of the pins |14. When the inner ends of the toggle links are urged towards the brake disc the brackets II3 are Iforced apart against the tension of the springs I I'I and result in the brake band being expanded out of engagement with the brake disc and into abutting relation with the inner periphery of the cylindrical side wall IIO of the drum |00. When the inner ends of the links are released so that the springs II'I effect contraction of the brake band around the brake disc while the disc is rotating inone direction one of the brackets |13 strikes against the adjacent end of the cutout ||2 and so anchors the adjacent end of the brake band to the drum that the band effects the desired braking of the disc. vWhen the springs urge together the two brackets while the brake disc is reversely driven the other bracket strikes against the adjacent end of the cutout vI I2 and so anchors the connected end of the band to the drum that the brake effects braking of the disc. When the brake is applied or rendered operative the shaft 45 and the motor armature are brought to rest. Release of the brake frees the shaft 45 so that -it together with the motor armature is capable of rotating. An actuator block I'I8 and a U.- shaped bracket IIS operate automatically to release the brake when the rock shaft 80 is rocked in either direction from its neutral or off position in order to effect drive of the motor. The actuator block |I 8 forms a part ofthe portion 10 of the rock shaft that -is disposed between the

plates

82 and 83 and hence rotates or rocks conjointly with the rock shaft. The bracket ||9 f is located between the actuator block I I8 and the inner ends of the toggle links 1I5 and is arranged so that the intermediatepart thereof is in the path of, and engaged by, the actuator block |I8 when the latter is rotated in either direction in connection with closing of the reversing switch. The side legs of the bracket Ii extend in the direction of the brake disc and have arranged that it effects release of the brake re- .gardless' of the direction of rocking of the rock shaft 80. In other` words, due to the specific design and arrangement of the actuator block I i8, release of the brake is effected automatically when the rock shaft is rocked in either direction with respect to its neutral or off position.

`The manually operable control mechanism 2|` for the reversing switch I9 and the brake 20 is located outwards of the plate 83 and consists of a centrally fulcrumed or -first class lever |20 and three gear segments I 2I, |22 and |23. The lever |20 normally extends horizontally and has the ends thereofbent outwards at right angles to form forwardly extending ears |24. The central portion of the lever 20 is rotatably mounted about the centralportion of a horizontally exwith handles (not shown). lWhen one of the.

tending pin |25. Such pin isrdisposed, for the most part outwards of the plate 83 and has the inner end thereof welded or otherwise xedly secured to the extension |0I .of.said plate. The apex'portion of the gear segment |2| ts against and is welded to the central portion of the lever |20 in order that said gear` segment |2I rocks conjointly with the lever. The gear segment |22 has one portion thereof in mesh with one portion of the Agear segment I 2| and has its apex portion xedly connected to one end of a horizontally extending Vshaft |26. Such shaft extends completely through thev tube 84 and is journalled in bearings |21 in the ends of the tube.

The other end of the shaft |26 projects beyondV the lowerarcuate wall 25 and'is provided with a radially extending stop finger |28, the purpose.

of 'which is described hereafter. The gear segment I 23 meshes with anotherportion of the gearsegment |22 andhas its apex portion suitably fixedly connected to theouter end of the rock shaft su. when the iever 2| is rocked in n one direction it operates through the medium of I the threegearv segments to rock the rock shaft in rock shaft. Rocking of the Vlever is effected by way of a pair of depending side by side pullcords |29. The upper ends of these cords. are connected Ybysnaphooks |30 to the forwardly extending right angles ,ears |24 on the ends of the lever. The lower ends of the cords are provided cords is pulled downwards the lever is rocked in one direction and results in drive of the motor in one direction and concurrent release of the brake 20. When the other "cord is pulled downl 1I l. wards the lever |23 is rocked in the reverse direction and results in reverse drive of the electric motor and concurrent release of the brake. When neither cord is subject to a downward pull the lever |20, due to the action of the helical spring 95 and the arm 96, assumes its neutral position wherein it extends transversely horizontally. The electric motor I6 operates so long as one of the cords |29 is pulled downwards. Release of the cord results in the reversing switch being automatically shifted into its neutral or off position and resultant stoppage Yof the motor and application of the brake 20.

The stop finger |28 which, as hereinbefore described, is xedly connected to, and extends radially from, one end of the shaft |26 coacts with a pair of stop pins |3| and |32 automatically to effect stoppage of the electric motor when the chain hook 1Q is lowered or raised to a predetermined extent. The pin |3| is connected to the end of the chain I8 that is anchored and is adapted when the chain is payed out to a predetermined extent to strike against the nger 28 and cause the latter to rock or swing. Such movement on the part of the finger |28 operates through the medium of the shaft |26 the gear segmentsKV |22 and |23 and therock shaft B- to return the reversing switch to its neutral or off position. The other stop pin, i. e.. the pin |32, is connected to the end of the chain having the hook 'l0 and is adapted when the hook end of the` chain is drawn towards the sprocket to a predetermined extent to engage the finger |28 and swing the latter in such direction that it operates through the medium of the aforementioned partsto return the reversing switch to its neutral or off position.

In addition to the parts heretofore mentioned the hoist comprises a removable cup-shaped shell |33 for enclosing the housing 22, the Vreversinq switch` I9; the brake 2|! and substantiallv all of the manually operable control mech-V anism 2|. This shell is preferably in the form of a one-piece metal stamping and comprises a continuous side wall |34 and anV end wall |35. The side wall is elliptical in cross section andy has the free marginal portion thereof shaped to it around the outer edge of the vertically extending inner wall 32 of the housing 22. When the shellY |33 is in its operative position; as: shown

inFigures lA

2, 3, and 6. the axis of the con-V tinuous side wall |34 extends horizontallv and the end wall |35 is disposed outwards of the plate 83 having the extension |0I. The shell is manipulated into its normal operative position by sliding it horizontally so as to bring the side wall |34 into encircling relation with the housing 22 and the other parts heretofore :mentioned. In connection with sliding of the shell into plane the side wall |34 is guided bv the webs 4f! and` M. Such webs serve in coniunction with the inner end wall 32 of the housing 22 to suo- Y port the shell against lateral displacement. The shell end wall |35 has in the upper central 'oortion thereof a hole |36` through which extends theV outer end of the pin |25 when the shell is in place. In addition to the hole |36 the shell end wall has a pair of oonositely extending arcuate slots |31 throughwhic'h extend the outer portions of the ears |24 at the ends ofthelever |20 of the manually operable control mechanismV 2 A disc-like cap |38 serves releasably to hold the shell |33v in its roperative position. The central portion of, the cap; is connected to the outer end of the pin |25 by a conventional bayonet catch |39. When. it is desiredv to removel the shell |33 the cap |38 isv turned orl rotatedf sufiiciently to release the bayonet catch. Thereafter the cap is removed so as to free the shell forv outward sliding movement.

The herein described electric chain hoist effectively and eliiciently fulfills its intended purpose and, due to the particular arrangement of itsvarious component parts occupies but a comparatively small space. that the electric motor I6 is located onlone side of the frame l5 and all ofthe other parts, withl the exception ofthe sprocket Il, the chain |8 and the hook 2l, aremounted on the other side of the frame, the hoist, when supported by either of the two hooks is properly bal-a-ncedwithoutthe necessity of employing any counterweight.

By having the reversing switch 9, the brakev 20 and the manually operable control mechanism 2| mounted all within the removable cup-1 shaped shell 23A such parts arev readily accessible for inspection, repair or replacement purposes merely byremoval of the shell. Inview of the lbe modified within the scope of the appended claims without departing from the spirit and scope ofthe invention.

Having thus described' the invention, whatwe claim as vnew and desire to secure by Letters.

Patent is:

1. An electric chain hoist comprising a frame provided with upstanding means for attaching it to an overhead supportfandconsisting of a vertically extending Wall, a large'sized upper arcuate side wall connected to one side of the vertically extending wall and arranged so that the ends thereof terminate-butla comparatively small distance apart and are generally at the bottom, and a small sized lower arcuateA side wall of less width than the upper arcuate sidewall, connected to said one side of the vertically extending wall, disposed between the ends of the upper arcuate side wall and having its ends facing generally downwards;- a housing connected '-to. the other side of the vertically extending wall of the frame', a horizontal shaft extending through said vertically extending wall and having one end; thereof disposedY concentrically within the lower arcuate side wall and provided' -With a sprocket and its other end disposed witha chain trained around the sprocket, held on the sprocket by the aforesaid in `the housing,

lower arcuate sidewall and provided at one end thereof with load carrying means, an electric motor disposed Vadjacent saidI one side of the vertically extending wall and embodying a suba horizontal armaturey Shaft having one endV thereof extendingfthrough said vertically extending wall andA into said housing, and gearing within the housing' and between the two shaftsfor driving the sprocket from the motor.

Z'lYAn-electric chainhoisti comprising a frame;

consisting of a vertically extending Wall, a com- By reason of the fact hookv adapted to suspend the Ahoist from an overhead support and having the shank thereof-extending downwards through the top portion of the upper side wall of the frame, a housing connected to the other side of the vertically ex tending wall of the frame, a horizontal shaft extending through said vertically extending wall and having one end thereof disposed concentrically within the lower arcuate side wall and provided with a sprocket` and its otherend disposed within the housing, a chain trained around and a small sized lower -Yarcuate side wall con-fA nected to said other side of said vertically ex tending wall, positioned in substantially centered relation with the lower end of the enlargement, disposed between the ends of the-upper arcuate side wall, and having its ends facing generally downwards, a housing disposed adjacent said one side of the vertically extending wall and embodyin'ga vertically extending inner end wall with a diagonal opening shaped conformably to the enlargement and in which said enlargement the sprocket, held onsaid sprocketv by theafore" l saidf'lower arcuate side wall; and providedatv one end thereof withy loadV carrying means/,janA electric motor disposed adjacent said onejside of the vertically extending wall and embodying ay substantially cylindrical casing' with one end thereof connected directly to the outer side margin of said upper arcuate side wall and spaced outwards from the outer side margin of the lower arcuate side wall, and in addition a horizontal armature shaft having one end thereof extending through said vertically extending walland into said housing, and gearing within the housing and between the two shafts 'for driving the sprocket,

from the motor.

`3. An electric chain hoist comprising a frame provided' with upstanding vmeans for attaching it toY an overhead support and embodyinga ,verl-k' tically extending wall with a' diagonallyextend'- ing enlargement on one side thereof, a housing,v

positioned adjacent said one side of the Lvertically extending wall and embodying a vertically extending inner end wall with a diagonal opening therein shaped conformably with the enlargement and in which the enlargement is seated,

a horizontal shaft extending through vthat por-v tion -of the vertically extending side wall that embodies the lower end of the'enlargement andhaving `one end thereof disposed within the housing and its other end exteriorly disposed and provided with a sprocket, a chain trained around the sprocket and provided at one end thereof with load carrying means, an electric motor disposed adjacent and mounted on the other side of the vertically extending wall of the frame and havingV a horizontal armature shaft with one end `thereof extending through the portion of .Y said vertically extending wall that embodies the upper` integral'` diagonally extending enlargement onis" seated, a horizontal shaft extending through the portion of the vertically extending wall of the frame that has the lower end of the enlargement and having one end thereof disposed within the housing and its other end disposed concentrically within the lower arcuate side wall and provided with a sprocket, a chain trained around the sprocket and provided at one end thereof with load carrying means, an electric motor disposed adjacent said other side of the vertically extending wall of the frame and embodying a substantially cylindrical casing with one endthereof connected directly to said upper arcuate side wall, and in addition a horizontal armature'shaft extending through the portionl of the vertically extending wall with the upper end of the enlargement and into the housing, and gearing within said housing and between the two shafts for driving the sprocket from the 1 motor.

5. An electric) chain hoist -comprising a cast metal frame consisting of a vertically extending lwall with an integral diagonally extending enlargement on one side thereof, a large sized upper arcuate side wall connected to the other side ofthe vertically extending wall, positioned in substantially centered relation with the upper end of the enlargement, and arranged so that theends thereof terminate but a comparatively smallfdistance apart and are generally at the bottom, and a small sized lower arcuate side wallv connected to said other side of said vertically extending wall, positioned in substantially centered relation with the lower end of the enlargement, disposed between the ends of the upper arcuate side wall, and having its ends facing downwards generally, a swively type hook adapted to suspend the hoist from an overhead support and having the shank thereof extending downwards through the upper or top portion of the upper side wall, a housing disposed adjacent said one side of the vertically extending wall and embodying a vertically extending in` ner end wall Vwith a diagonal opening shaped conformably to the enlargement and Vin which said enlargement is seated, a horizontal shaft extending through the portion of the vertically extending wall of the frame that has the lower end of the enlargement and having one end thereof disposed within the housing and its other end disposed concentrically within the lower arcuate sidewall and provided with a sprocket,

a chain trained around the .sprocketpand provided at one end thereof with load carrying means, an electric motor disposed adjacent said other side of the vertically extending wall' of l the frame and embodying a substantially cylindrical casing with one end thereof connected directly to said upper arcuate side wall, and in additionla horizontal armature shaft extending through the portion of the vertically extending wallfwith the upper end of the enlargement and intothe housing, and worm and worm wheel i variety gearing within said housing and between I Y the two-shafts for driving the motor.

6. An electric chain hoist comprising a cast metal frame provided with upstanding means forattaching it to an overhead support and consisting of a vertically extending wall with an integral diagonally extending enlargement on one side thereof, a large sized upper arcuate side wall connected to the other side of the vertically extending wall, positioned in substantially centered relation with the upper end of the enlargement, and arranged so that the ends thereof terminate but a, comparatively small distance apart and are generally at the bottom, and a small sizedv lower arcuate side wall connected tosaid other side of said vertically extending wall, positioned in substantially centered relation with the lower end of the enlargement, disposed between the ends of the upper arcuate side wall, and having its ends facing generally downwards, a housing disposed adjacent said one side of the vertically extending wall and embodying a vertically extending inner end wall with a diagonal opening shaped conformably to the enlargement and in which said enlargement is seated, a horizontal shaft extending through the portion of the vertically extending wall of the frame that has the lower end of the enlargement and having one end thereof disposed within the housing and its other end disposed concentrically within the lower arcuate side wall and provided with a sprocket, a chain trained around the sprocket and provided at one end thereof with load carrying means, an electric motor disposed adjacent said other side of the vertically extending wall of the frame and embodying a substantially cylindrical casing with one end thereof connected directly to said upper arcuate side wall, and in addition a horizontal armature shaft extending through the portion of the vertically extending wall with the upper end of the enlargement and into the housing, and irreversible gearing disposed within the lio-using, operative to drive the sprocket from the motor, and embodying a diagonal shaft extending at right angles to and between the armature shaft and the sprocket carrying shaft, aworm on the armature shaft, a worm wheel mounted on the upper end of the diagonal shaft and in mesh with the worm, a worm on the lower end of said diagonal shaft and a worm wheel mounted on said one end of the sprocket carrying shaft and in mesh with the last mentioned worm.

7. An electric chain hoist comprising `a, frame provided with upstanding means for suspending it from an overhead support and emboding avertically extending wall, a housing connected to one side of the vertically extending wall and consisting of spaced apart inner and outer end walls and a continuous side wall between the` end walls, a horizontal shaft extending through the vertically extending wall at a point beneath the suspending, means, having one end thereof disposed in the housing and its other end exteriorly disposedV and provided with a sprocket, achain trained around the sprocket and provided at one end thereof with load carrying means, a reversi-y ble electric motor mounted on the other side of the vertically extending wall of the frame and having a horizontally extending armature shaft disposed above the sprocket carrying shaft and sprocket from the having one end thereof extending through said-I vertically extending wall and. housing and of such length that its extremity terminates a small dis- ,y 16. tance outwards of the outer end wall of the housing, gearing within the housing and between the two shafts for driving the sprocket from the 3 motor, a reversing* switch adapted to control the motor and mounted adjacent to, and outwards of, the continuous side wall of said housing, and a `brake operative to brake the motor when Athe switch is in its neutral or olf position, located directly outwards of the outer end wall of the housing `and including a rotary element mounted xedly on the extremity of said one end of the armature shaft.

8, An electric chain hoist comprising a frame provided with upstanding means for suspending it from an overheadsupport'and embodying a vertically extending wall, a housing connected to one side of the vertically extending wall and consisting of spaced apart inner and outer end walls anda continuous side wall between the end walls, a horizontal shaft extending through the vertically extending wallat a point lbeneath the suspending means, having one end thereof disposed in the housing and its other end exteriorly disposed and provided with a sprocket, a chain trained around the sprocket and provided at one end. thereof with load carrying means, a reversible electric motor mounted on the other side of the verticallyY extending wall of the frame and .having a. horizontally extending armature shaft disposed about the sprocket carrying shaft and having one end thereof extending through said vertically extending wall and housing and of such length that its extremity terminates a small distance outwards of the outer end wall of the housing, gearing within the housing and between the two shafts for driving the sprocketfrom the motor,v a reversing switch'adapted to control the motor and mounted adjacent to, and outwards: of, the continuous side wall of said housing, a

Y its endj wall is outwards of the brake and the nance position.

free margin of its side wall is disposed adjacent the inner end wall of the housing.

9. An electric chain hoist comprising a frame provided with upstanding means for attaching it to an overhead support having a housing at one side thereof, a horizontal shaft journaled on the frame beneath the attaching -means and having one end thereof extending into the housing and its other end disposed exteriorly and provided with a Isprocket `for a hoisting chain, a reversi- 4 ble electrick motor mounted on the other side of.

the frame having a horizontal armature shaft extending into. the housing, gearing within the' housing and between the two shafts for drivingthe sprocket from the motor, a reversing switch adapted to control the motor positioned normallyin'close proximity to one side of the housing, and a mounting for the switch embodying means whereby said switch may be swung bodily away from the housing into an inspection or maintey 10".v Anelectric chain hoist comprising a frame provided with upstanding means for attaching it tol anoverhead support having a housing at one sidewthereof, a horizontal shaft journaled on the "frame-fbe'neaththe. attaching means and having-v one end thereof extending into the housing and its other end disposed exteriorly and provided with a sprocket for a hoisting chain, a reversible electric motor mounted on the other side of the frame having a horizontal armature shaft extending into the housing, gearing within the housing and between the two shafts for driving the sprocket from the motor, a reversing switch adapted to control the motor positioned normally in close proximity to lone yside of the housing, a removable shell extending around and adapted to house the housing and switch, and a mounting for the switch embodying means whereby when the shell is removed said switch may be shifted laterally away from said one side of the housing into an inspection or maintenance position.

11. An electric chain hoist comprising a frame provided with -upstanding means for normally suspending a hoist from an overhead support and having a housing, a horizontally extending shaft journalled onthe frame beneath the suspending means and having one end thereof extending into the housing and its other end exteriorly disposed and lprovided with a sprocket, a reversible electric motor mounted on the frame, gearing in the housing for driving the sprocket from the motor, a horizontally extending anchor post mounted on the frame to one side of the sprocket, a roller chain trained around the sprocket and lhaving a hoisting hook at one end thereof andits other end pivotally connected to the anchor post by way of a pair of laterally spaced links, and a free- -ly rotatable roller mounted on the anchor post between the links, disposed in alignment with the sprocket and arranged and adapted so that it serves in the event that the hoist is sus-pended by the chain h-ook instead of the suspending means to guide to or from the sprocket the portion of the chain that extends between the anchor post and the sprocket.

IRVING R. METCALF. GEORGE E. BOCK.

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

UNITED STATES PATENTS Number Name Date 411,165 Noack Sept. 17, 1889 1,938,071 Hummel Dec. 5, 1933 2,116,013 Carson et al May 3, 1938 r 2,243,664 Baird May 27, 1941 2,335,571 Schroeder Nov. 30, 1943 2,382,644 Lear Aug. 14, 1945 FOREIGN PATENTS Number Country Date 8,129 Greet Britain 1 -mw of 1908