US2561997A - Frame for vertically swinging conveyers - Google Patents

Description

July 24, 1951 Filed Dec. 31, 1947 O. E. SMITH FRAME FOR VERTICALLY SWINGING CONVEYERS 5 Sheets-Sheet 1 INVENTOR.

ORV/LLE E. S/WTH ATTDRNEY July 24, 1951 o. E. SMITH 2,561,997

FRAME FOR VERTICAL-LY SWINGING CONVEYERS Filed Dec. 51, 1947 5 Sheets-Sheet 2 INVENTOR. ORV/4L5 E. .SM/TH 3 BY ATTORNEY July 24, 1951 o. E. SMITH FRAME FOR VERTICALLY SWINGING CONVEYERS 5 Sheets-Sheet 5 Filed Dec. 31, 1947 INVENTOR. ORV/ALE E. S/W/TH BY ATTORNEY J 1951 o. E. SMITH 2,561,997

FRAME FOR VERTICALLY SWINGING CONVEYERS Filed Dec. 31, 1947 5 Sheets-Sheet 4 I INVENTOR. ORV/LLE E. SMITH July 24, 1951 o. E. SMITH 2,561,997

FRAME FOR VERTICALLY SWINGING CONVEYERS Filed D80. 31, 1947 5 Sheets-Sheet 5 INVENTOR. 0R V/LLE E. jM/TH //'g- 9. i i W ATTORNEY Patented July 24, 195i 1 "FRAMEFORV RTICALLY SWINGING""""' ,Oi'vflle Grand Rapids, Mich; assignor I to Rapids-Standard wman In 7. G and. Rapids, Mich., a. corporation of Michigan H Applicationflecember 31, 1947, SeriaLNm 794,982-

This invention relates to a conveyor elevating mechanism. and more-particularly to. one comprising atoggle. mechanismzmoperated-bv a rod of variable lengthand connected for -.chang ing. the

angular position of thenvconveyor bed. with respectto-thehorizontal; V v

In; the design. of conveyor mechanisms it is necessary toprovide one having the capacity for: changing the. conveyor. bed from. one, position to another with respect to; the horizontal. The difiiculty involved indev-ising such a mechanism complicated in part by the fact that it is desizable that the conveyorLw-hen in its horizontal or contracted position; should have its'bed as close: as possible to the floor resulting in little conveniently available room for the installation of the operating mechanism. In order that the elevator structure rin one position be-capable of extending to support the. raised bed and, in an.- other. position,,b e stored within the conveyor body;

it is necessary that themechanism fold upinto a I compactzmass as the conveyor bed is lowered into its horizontal position; concentrically sleeved,

hydraulic units are capable of performing this function. but they areaso costly to produce-- that final: product uneconomical, It is, there.- fore, necessary to provide a mechanical linkage witlrtheiurther limitation that. thelines of force generated within the linkage, asthe variousparts thereof, change their relative positions, must providefor easy operation of the; unit. Further, the: resulting; unit, must be easilyoperablefby a manual crank or require, a, motor of. reasonably small horsepower. At the same time the various parts designed to perform this service must be small; enough to fitwithin the restricted area-of the conveyor outline. I

In; addition to the requirements set out above, the; unit must develop sufficient strength that :the conveyor may be used for heavy loads without vfear of structural failure, and it must be so balanced that the constantly shifting loads will not materially change its center of gravity. Furthermore; it must be rigid enough to eliminate any sway'when in the raised or open position. Allof these, characteristics are necessary to provide a onveyor which issafe to operate; I

. 'Theunit must. be simple in order to reduce both the; initial cost and to eliminate, as far as possible, the. problem of; subsequent breakdowns and the; consequent delays; and repair costs. Heretoioreysolutions ofone type or another have been found for-each of these problems singularly, but. until the applicants invention a. mechanism providing a; satisfactory solution for all of thesevproblems. combination did ot ex t, Howe er, thr u my combinationash r nfl s: c os d-tan i i ni, O H $36 11 va n w thers be n reate f t. s e efo ea ar o e v'm fli' tion to provide a conveyor elevating mechan sm capable ofprovidin a wide latitude of. inclined positions ior. thejconvey'orbed. a I

It is a further object of my invention to provide a mechanism such that itvvill occupy only'a small area'eios'e to the supportingfioor 'tvliell the do'h' vyor bed is lil'itsihorizol'ital pdsitiollf A still'ifur'therr objet'o'f inventio'h'is to pro: vid 'siicli'a mechanism requiring a mmimum'of efiorttooperatejy I v An additional object ofln'y invelltl'oh ism 'provide a inechanism-which is structurally simple}, yet having high strength characteristics and ca: pab'le ofop-erationwithoutsidesway: Another object ofmyinvention is to provide an elevator mechanism having a maximum'safetv factor fortheoperator: Still another object of my inventionis topro vide such a mechanisnfiiesigned' foreificient and economical fabrication. v

Gther jects and purposes of'myinvention wili be apparent to persons "acquainted" with equip ment or this type upon examination of the co ecu-npanyingdrawings and reading of the follow in'gdisclosure I I l rrtla'e drawir'igs:

Figure-i l is an; oblique vievv'of my invention A I Figure 2 shows: my conveyor elevator-mocha; I

msmaimpartiallyextendedpositionh; .iFigure: 3: :showsrmy conveyor elevator mocha nism inafully extendedz'positioni Figure .4 sholwg'my conveyor elevator. mechae nisim inl-tuliylclosed: oatlowered; position :1 Figure 5 is a sectional View of m lconve'yor elevating Lmechanismas vi wed from the .plane V -V of aEigure-h butlshowing no part of; the conveyor bedorhed.supnortinefram \Eigurefilis a sectional view, of. my invention taken along th -p ane @iIer f igured cut in air the partsexceptthe drivingshaft. Q

Figure? is a fragmentary, t,op,,sectionalvi ew showing 1 section allet'h partsalong the m m;- ber 9f vatia eile el exc t he i eshaft which isshown-in full; i

Figure 8 is; a fragmentary, top, sectionalview the relative positions of the operating parts of my invention in closed position.

Figure 14 is a side elevational 'viewof my conveyor showing a modification of the supporting structure.

In accomplishing the objects and purposes ofmy invention I have provided a conveyor elevating mechanism utilizing a toggle linkage, one leg of which constitutes a triangle, pivotally supported at one corner, connected at another corner to the conveyor bed through the second leg of the toggle, and connected at the third corner to a threaded, extensible operating member. Changing the length of the threaded operating member causes the triangular leg to pivot on its support thereby operating the toggle for raising or lowering the conveyor body.

The terms forward and rearward will be freely used in the description of my invention and shall be taken to mean forward toward the raisable end of my conveyor, or the left hand side of Figure 2, and rearward toward the end of my conveyor having the support of fixed height. The terms upper and lower will be taken to refer to the conveyor as shown in Figure 2.

For illustrative purposes herein the conveyor is shown as having one end supported on the adjustable mechanism of my invention and the other end supported on a stand of fixed height.

4 pivot mounting Will be described more fully hereafter.

The drag links I are formed from tubular stock with the lower end M of each link flattened to provide a substantially rectangular portion surrounding the pivot pin (Fi ure 5). Each of the pivot pins i5 is rigidly attached -to a-drag link by welding or other suitable fastening means. A hole is provided through the pivot pin to receive the cotter pin 16.

The rocker plates 8 are triangular in shape and formed withbeads ll along ,a portion of each side extending inwardly toward the adjustable member 9 (Figures 2 and'll) These beads increase the compressive strength of the plates. At the link corner l8 of the rocker plates there is provided an opening surrounded by an annular boss for re- It will be understood that this is illustrative only and that the conveyor may be supported at both ends by vertically adjustable mechanisms, either or both of which may be that of my invention herein disclosed, or, alternatively, the end here shown as on the stand of fixed height may be supporteddirectly on a fixed platform, suchas a loading dock, or may even be supported on the floor, providing only that such support permits it to pivot as the conveyor bed is moved through varying positions with respect to the horizontal;

Referring specifically to the drawings, the numeral l refers to a conveyor bed pivotally mounted on its rearward end to a support stand 20f height assumed for purposes herein to be fixed, and on its forward end to a support platform 3 by means of the elevating mechanism 4 and associated frame 5. Both the support stand 2 and the support platform 3 are mounted upon casters 6 (Figures 1 and 2).

The elevating mechanism consists of a pair of drag links I, a pair of triangular rocker plates 8 and an adjustable member 9. Each of the drag links I at its upper end is welded to a tubular casing l0 (Figure 9). Each such casing is equal to one-half the space existing between the frame members ll of the conveyor bed i. This enables the casing to occupy the entire space between the frame members and prevent any lateral movement thereof. A supporting shaft 12 passes through each of the casings l0 and projects at each of its ends through suitable openings 83 in the frame members ll (Figures 2 and 9). Lateral movement of the shaft is prevented by'a cotter pin'l3 on each end (Figures 2 and 9). The lengthwiseposition, on the conveyor bed,of this 85 extends between the two rocker plates and aceiving the pivot pin l5 of the drag link 1 (Figures 5 and 11). The annular boss 20 projects outwardly from the rocker plate 8 in the opposite direction to the bead. At the mounting corner 2| of the rocker plate an annular mounting boss 22 .iswelded to the rocker plate and projects outwardly therefrom-in the same direction'as the boss 20 (Figures 2, 5 and 11). A threaded opening 23 for receivingv a set screw extends through the boss 22 at a right angleto the central opening therein.

At the third, or operating, corner 24 .of-the rocker plate 8 another annular boss 25 (Figure 11) is welded to the plate extending in the opposite direction to the boss 20. -A short shaft 26 seats within this boss and extends outwardly therefrom. This shaft 26 is rigidly fixed to the boss 25' by welding or other suitable attaching means and is provided with a cotter pin receiv ing opening near its projecting end. Substantially midway between the corners l8 and 2| of the rocker plate an opening 21 is provided through the plate (Figure 3). -A tubular spacer bolt 86, held by the nut 87 (Figures 5 and 11), passes through the openings 21 and the spacer 86. This spacer is located such that when the conveyor bed is in its position of maximum ele-'- vation it will not interfere with the adjustable member 9.

A bearing tube 28passes through the boss-2 in each of the rocker plates 8 and is rigidlyheld against both axial and rotatable movement rela-' tive to the rocker plates by the set screw-29 in-.- serted in the'ope'ning 23. A'pivot shaft 30 passes through the bearing tube 28. i The frame 5 is a trapezoidal structure wherein each of the non-parallel sides 3| consistsof 2 tubular rails'32 and 33 bent through a 90-degree are on one of their respective ends (Figures 2 and 5-). These rails are placed with theircurved ends in opposite'directions and'welded'together. A structural spacer 34 iswelded between the rails "at each end. At the lower end of the frame the curved rails are welded to the tubular cross member 35. A hinge shaft 36 passesthrough the center of the cross member and projects from each'end thereof a sumcient distance to pass through openings in the base brackets 37. The cross member 35 is of sufficient length to contact the base brackets 37 and thereby prevent any lateral movement. The support platform 3 is not described in detail in this application as it maybe of any suitable construction, such as that dis--- closed in the co-pen dingapplication of Bert Woldring, Serial Number 577,793, filed February 14, l945','entitled Dolly, now Patent 2,452,978;

1 pass through the openings andare' rotatable 5 $tibstantially niidway between thbhdS df th sides-3! arectang-ular support plate Ell (Figures 1' and 2)" is- -afiixed between the rails Bl and! by Welding-and at such an angle to the-centr line of tlierails that the twoplates 'are parallel and at a right angle to the cross member- 3 Axially aligned openings 39 are providedin ease plate (Figure 2). f Theends-ofthepivot shaft3U 10 o'n 'each of its ends and'isth'ereby held agains axialmovernent. I "A mounting bracket lfi --(l 'ig'ures- 1; 2; '5' and-6); having 'an-fopeninfg il in fits forward endfis at tached toeach of the 'frame'menrbersd the conveyor bed I by any suitable fasteningmeans such as bolts 52' or-r'ivets." Through theopeii'ing 41' in each of these brackets passes aftubula'r frame mount to for the frame- 5. The-endof the curved rail at the upper end of the side 3'1 of the, frame is welded-to a frame mount lz tFig v The frame mounts "12 "pass through and fro tatably support the yoke 43 by means of the openings l8 (Figures 5 and'B). Inside the yoke is abevel {gear ill a collar. (separated from direct contact with the vokesby the, filf 4.6. A further washer Ii-l is provided adjacent the. s de of. h yoke away remthe betel s t a; a-bu-tsthe inner end :of one of the frame; mounts 45-2). A crank shaft 418; passes through. the cent r of t rame mounts. 42;, t w shers 4.5; and 47 and. the bevel gear 44. A washer 49 seats @on the crank shaft 49 adjacent the exterior SllIiaOQo-f each bracket 42 and abuttingthe outer end of each of the f-rame mounts 42. One end; of the crank .shafst as. extends outwardly from the bracket 42 to provide amount for the crank, handle so. The crank handle so .is separated from the washer at by the spacer 151 in order thatthe handle will clear the conveyor bed when operated. The. center of the yoke $3, is. provided with" nf. opening 53 to receive the threadedfshaft 5'4. (F1 7) Inside the yoke a bevel gear .55, having a, diameter" approximately double that of the be. elj gear id but in other respectsisimilar' to it', j is: mounted on the threaded shaftfBAiandfseparalted. new the yoke by the Washer 55,. Exterior of the yoke a thrust bearing 51. surrounds the-shaft 54' a d is separated 'frornfthe, yoke by thepr es--- sureplate 58. A tubular -shie1d59of vs'ufi'i t diameter to receive the thrust tube .611 (Ei'gli i fi land 8) surrounds the threaded shaft, 5.1L A collar'iil having a portion 510f sufficiently re: duced diameter to fit within the tubularfshield islvrigidly attached to the shaft, 15.14 by "th fl prd pin 63. The internal opening .of the thrust tube [Bl] of sufficient diameter to receive the 1th "add shaft 5'4. A not. (Figure 3,) havingared' portion received intov the thrust 'tube 604s". welded to the end of the thrustftube received into the shield. Both the nut 64 and the 'haft' Stare equipped with any type :pfthread s bl'e for power delivery such as an Acme type thread; The threadin on the shaft 54 extends from its rearward end forwardly to a point inside the shield 59..adjacent to the collar 6!. ;A tapered opening 65 designed to receive a stop'pinis provided ih the end of-the 'th-readedshaft." The forward end of the thrust tube so' is weldedto'a substantially lJ'-shaped"sadd1e"66' comprising an end piece-'61 and side'sdlo, 91b} therein. The bearing tube 28" abuts theiplates 3 -8 13 betweenthem are maintained.

aseatea en angleof 'sub'sta-ntially 30 to the end' piece' ol -"and joinfthe end piece =6lto the sides 91a and lllb which are at a, right angle to the end picel A pair-of compression bars 9-2 connect'the side piecess l a and 91?; on their topand bottom surfaces respectively. 'The sides and-the end piece may' befrnadefromseparate parts assembled 'by welding but preferably they are formed from-a single part by bonding. The compress ion bars' 'ar'e assembled to the'sides Sta and Mb Ely-Welding. I -The thrust tube is affixed theretoat the center' of "the end piece '61 (Figural-5'). Axially aligned openings 63 are provided-in the sides Qia and ill!) of the saddle 66 parallel to the-#thrust' tube to 'rotatably receive the shafts 2B oftherocker lplatesia (Figures 8 and 11)..- The various parts of the conveyor may be made from anysuitable material but to develop maximum strength and to facilitate the use of a welded construction, steelis preferred. s I '-By= experimentation it has been found that; although other dimensional relationships will op era'tawith varying degrees of effectiveness, one highly satisfactory proportioning of the parts. of: the adjusting mechanism is as follows: Thespacing'ibetween" the pivot point of the supporting frame 5*at -the'bracket "40 and the mounting point of the pivotshaft all on the supporting frame 5 is -24=:inche's, and a similar spacing exists between the point of attachment of the drag links I and A vertical spacing of 2 inches between the crank s'haftdil :and the'plane of the drag link attachment' point on the frame members II has been found desirable in this embodiment to permit/the rocker plates8 to rotate without interference with the conveyor bed. When these dimensions are used; the optimum dimension on the rocker plates -'8 between the center of the opening at the mounting'c'orner 21 and center of the opening at the link corner 18 is 14 inches and the effective length of drag link is 16 /2 inches. These dimensions. of =course,- may be increased ordecreased while retaining the mechanical efiiciency afforded th'em 'if's'ubstantially the same proportions H i v Assembly r f Thebevel gear 55 is assembled to the threaded shaft "-54 by passing it over the unthreaded end andattachingit thereto by insertion of the pin 69 through the collar of the gear and a suitable hole in'the. shaft (Figure 7) The ;pin' is held in-place by'any suitable arrangement such as a head ll)" on :one end and a cotter pin 1 r'onthe other; The spacing Washer 56 is then passed down "the threaded shaft 54 and the latter installed in th' opening'53. The frame mounts 42, togetherwith theframe 5 welded thereto, are inserted in the openings l9 and the resulting assemblyis in-- stalled Jon theconveyor frame H by insertion of the: frame mounts 42 into the openings M in the mounting'brackets 40 which are in turn attached to. theframe members I I by theinstallation bolts 52. l The bevel-gear 44 together with the spacing washer llii is held in place and the crank shaft4z8 is inserted; through, one frameflmount- 42, the;

washer; 411,, the bevel gear 44, the spacing washer 4.6 and the second framelmount 42. The washers Hihre put inplace, the spacerz5 I slipped onto the end ao'f' thesha'ft 48 and the cotter pinslznand arethen" installed f to prevent further? lateral movement of the crankshaft 48. The retaining pin 14, similar to pin 69, is then inserted through appropriate openings in the collar 45 of the bevel gear 44 and the crank shaft 48. A further cotter pin,'l5 is installed in an appropriate opening in the shaft 48'to retain the washer 41. Thetwo washers 49, held in fixed axial relationship to the crank shaft 48 by the , cotter pins 12 and 13 pre vent lateral movement of the shaft 48, yoke 43, and associated assembly. Thecrank handle 5ll is seated on the end of the shaft and held into place by the set screw 16. This completes the assembly of the parts in the areaproximate to the conveyor bed.

. To complete the assembly of the adjustable member 9 the pressure plate 58, thrust bearing 51 and collar 6| are slipped into place along the threaded shaft 54. The collar 6| is held against rotation relative to the threaded shaft, by installation of the tapered pin 63. This pin is so made that it will snugly seat in the tapered opening 11 Without projecting out of either end thereof. The shield 59 is then fitted over the reduced portion 62 of the collar and fixedly attached thereto b the set screw 18. To prevent subsequent loosening of this set screw it may be tackwelded to the outer surface of the shield.

The welded assembly including thesaddle 66 and the thrust tube 60 are then added to the existing unit by threading the nut 64 onto the threaded shaft 54. When the threaded shaft has passed through the nut 64 a suffioient distance to align the opening 65 for the stop pin 19 with the opening 80 in the thrust tube, the tapered stop pin 19 is installed and peened down to prevent subsequent disengagement. The length of the shield 59 is such that when the openings 65 and 80 are aligned they will not be covered by it.

The rocker plates 8 are attached to the saddle 66 by inserting one of the shafts 26 in each of the openings 68 (Figures 8 and 11) The washers 8| and cotter pins 82 complete the assembly, hold: ing the sides 9 la and 9 lb of the saddle firmly but rotatably against the bosses 25. t v W The tubular bearing shaft 28 is passed through the boss 22 in each of the rocker plates 8 (Fi ures 5 and 11). The opening in the bearing shaft 28 is then aligned with the opening 39 (Figure 2) in each of the plates 38 and the pivot shaft 30 inserted therethrough and thereafter held against axial movement by a washer 89 and a cotter pin 90 on each of its ends. The set screw 29 in each of the bosses 22 is tightened against the bearing shaft 28. I I

The drag links 1 with a tubular casing l welded to the upper end of each of them are aligned with suitable openings 83 in the frame members I I of the conveyor bed I and the supporting shaft I2 is inserted through the openings 83 in" the frame and the center of the tubular casings l0 (Figure 2). The supporting shaft is held against lateral movement by the cotter pins l3 on each end. The pin l5 on the lower end l4 of each of the drag links is then passed through the boss 20 in each of the rocker plates 8 and the washer 84 together with the cotter pin [6 installed; The tubular spacer 85 is aligned with the openings 21 in the rocker plates 8 and the bolt 86 inserted (Figures 2, 3, 5 and 11). The nut 81 is tightened, clamping the rockers plates tightly against-the ends of the spacer 85 and serves to prevent deflection of the rocker plates eitherinwardly or outwardly. This completes the assembly of the elevating mechanism and its associated parts.

- The brackets 40 are located forward of the excessive gaps.

center ofthe. conveyor bed and the openings 83 are-located approximately midway between the brackets40 and the forward end of the conveyor. This position, however, is only a preferred example of which there can be many variations accordingto the requirements of the conveyor. The point of attachment of the drag links 1 to the frame I I must be so located that when the loads, are placed on the forward end of the conveyor there will be no tendency of the conveyor belt to pivot aboutthe elevating mechanism. on the other hand, the point should not be located farther forward than necessary because the further the openings 83 are spaced from the brackets 40, the less the distance the conveyor bed can be elevated.

Each of the parts assembled to rotate in relationship to each other are designed to provide sufficient spacing between them to permit easy movement but yet prevent any looseness due to This is necessary to provide a structure which will both resist wear and at the same time have no side sway.

Operation 'When the conveyor bed is in its lowered or horizontal position (Figure 4) the adjustable member 9 is in its fully retracted position and the rocker plates are rotated rearwardly about their mountings to the frame 5 such that the link corner l8 of the rocker plates is rearward of and below the mounting corner 2|. To elevate the forward end of the conveyor, the crank handle 50 is turned imparting rotation to the threaded shaft 54 thereby forcing the saddle 66 away from the yoke 43. This causes the rocker plates to be pivoted about the pivot 36 (Figure 2) in such a manner as to move the link corner l8 of the rocker plates upwardly, and forwardly. This in turn forces the drag links I upwardly raising the forward end of the conveyor bed I. As the conveyor bed is raised it pivots about the rearward support stand 2 at its point of attachment 88. Figure 2 shows this operation in partially com-' pleted condition and Figure 3 shows the conveyor bed fully elevated. The tightness of the threads on the shaft 54 together with the friction incident to the gears and crank shaft are suflicient to prevent the shaft 54 from being caused to rotate by the weight of the conveyor. This eliminates the necessity of any locking mechanism in connection with the crank shaft or threaded shaft.

The cross member 35 at the lower end of the frame 5 rotates about the hinge shaft 36 permit-' ting the forward support platform to move as the spacing between it and the rear support stand changes.

[The tubular mounts 42 rotate within the openings 4| permitting the frame 5 and the conv'eyor bed I to change their relative positions.

The yoke 43 is likewise free to rotate about the tubularmounts 42 as the extensible member 9 changes its angular position. By extending the tubular mounts 42 through the brackets 40, the loads imposed by the frame 5 are partially carried by the mounts 42 and the remainder distributed to the crank shaft 48 over an extended area thereby reducing both the possibility of de-' flection and the wear on the crank shaft. This arrangement also helps to distribute the loads imposed through the yoke 43 by the operation of the adjustable member 9. The same distribution of loads and reduction of wear is effected hythense ofthebearing shaft 28 tosupportthe rocker plates 8. The. shield 59. serves. to. cover. the threaded 5141 andprevent dust. and'other matter from ,entering thethreads. v r In Figures .12. and 13; therelative positions of thaconveyor. bed l.,mounting brackettll, adjust ablemember 9, .drag, links. "I, supporting. frames 5, .and'lrocker. plates flare. diagrammatically shown in. two, positions of adjustment, namely, when the cnnveyor. bed isiullyraised and. when. it is-iiully lowered, It isseenirom. these diagrams that. the :rocker pl'atesfl-are,v caused. to. pivot. about their mounting, corners. 2.1. by moving, thev operating corner 24. towardor away from, the bracket. 48, thus. actuating, the toggle comprising the drag links. and. that partof thet'ria'ngular plates beiiweenthe link corner I8 and the mounting, corner. 2i, While the mounting corner 21 and the supportingpoint [2' on the conveyor bed are each held in constant, spaced relationship with res'pect'to the bracket 557. By use of the triangular rockerplatesthe pointof attachment'of'the adjhstable member isseparated'from the pivot point .l'.8of"the toggle making it possible to operate the toggle through a greater range of angular relati'onships' without producing such relative po- "sitions of the toggle and the adjustable member that the'forces necessary for operation become excessive.- I

By'setting a portion of the sides of the saddle 6 6 at an'angle to both the end piece 6'! and sides Nu: and Q'lbthe tendency of the end piece '6! to deflect is-eli'minated; The compression bars 92 prevent thesaddle-from collapsing inwardly.

Although the conveyor as de's'cribedand shown in this application utilizes an elevating mechaon only one end it is possible to eliminate the rear support stand and substitute my elevating mechanism so thattheconveyor will be equipped With suchan elevating mechanism-on both of its ends-.- The manual operation of the crank shaft can-be easily changed to power by substituting a gear, pulleyor sprocket gear suitable for a chain and suitably engaging a motor thereto.

lit ma also be desirable undersomecirc'umstancesrto attach the. threaded shaft 54% to the saddle fifiins'uch a manner tha'tit'i heldagainst i'otation and. to attach the nut 60' operativ'ely in thebevel'gear'tfi such that the nut 60 rather thanathetthreade'dshaft :fniis rotated to cause extensionandretracti'on of the adjustable member fled that the leg: upon which the: elevating mechanzi'smifi is mounted'becomes a= fulcrum (Figure 14:. To: do this a supporting stand Hit: of. fixed height consisting of two rigid,.triangular, verti- "cal side's HH and the horizontal; base 102: is substituted for the supportingframe 5.- The rear endotthe conveyor is then left without-support either.- by a; floor, platform: or stand. In this manner-the expansiom-andcontraction-of the ad- ;justa-ble member 9-causes the conveyor bed to pivot "about: the crank. shaft 48 which irr this modified construction: is a.- point: of fixed height. The; mechanism of this invention.'thus functions "a means to adjustthe-positioir of the conveyor frame; with-respecttdthe. horizontal While a point intermediate itsends is maintained. at a fixed height.

It-wil-l be-evident. that variousother modificationsmay be. made the structure herein disclosed. but such obviousvariatiomwi'll all-beincluded. withinthe: scope. of my. hereinafter ap- The support for theconveyor'may be" so modi 1 0 .pendedgclaims, excepting; as said claims may by their own terms. expressly. provide otherwise.

I claim:

1. For a conveyorbedpivotally supportedatone end and having a supporting leg pivotally mounted in fixed. relation. tov the conveyor bed supportingthe other end. of saidbed, and. adjust,- ing means associated withsaid supporting leg ad}- justingthe height of saidother end. ofsaidbed, the improvement-in said adjusting means: com.- prising: a. pair. 015 member constituting. a toggle unit-connecting said supporting leg and said conveyor bedat-points on: each thereof, removed from the point of pivotal mounting of: said supporting leg; one of said members having a portion-pro.- viding an attachment point between. the-hinge point.- of. said. toggle and. the point. of" attachment of sa-id'toggleunit to, said leg and. spaced substantially iroma line. passing.- through saidhinge point and. theendoisaid onemember away-from said hinge point in adirection. away from sa'id point ofattachment. of. said. suppor.ting,.leg. .and said conveyor bedwhen said toggle is.in.openp0: I s'ition;v means or. variable. length pivoted at. one of itsend's. at saidpoint of. pivotal mountingof said supporting. leg and at. the. other of. its. ends pivoted. at saidlatta'chment point and operable for opening and' closing said toggle unit. I f

2. A conveyor having abed piVotallysuppmited at oneend'. thereof,,a supporting leg, pivotally mounted in fixed relation to the conveyor bfd supporting the otl'ier. endof said bed; and means associated with saidsupp'orting leg adjusting the height of said other endo'i said bed, the improve:- ment in said adjusting, means. comprising: a pair of members constituting. a. toggle unit connecti- .i'ng said. supporting leg and" said conveyor be'd at points on each thereof'removed from the point offlpivotalmounting of said. supporting leg; anarm on one member of said toggle unit extending in a direction away fromxsai'd leg, when said toggle i s.in open. position and outwa rdly froma line passingjthrough the hinge point of said. toggle unit. and. the. end of said one member away from said hinge point; a member of variable length mounted tolth'e outward end of said arrrrfior .opening andcl'osing said. toggle unit upon exten# sion and retraction of said member; means for. ex tending and. retracting. said member. of variable length. I p

, Ani-adjustablestand for aconveyor having a vertically. adjustable bed, comprising: a support.-

conveyor bed =.and.describing,an acute angle. therebetweenwhensaid. conveyor bed is in; raised po- 'sition; said supporting leg and said conveyor bed being substantially parallel when said. conveyor bed is-in maximum lowered position; a pair of links .constitutinga toggle unit, the first of said links being pivotally attached to saidconveyor bed at a point removed from said point of attachment of saidsupporting leg, the second of said, links being pivotally attached to said sup- 55 porting leg at apoint removed from the pointof its. attachment, to the conveyor bed; a member of. variable. lengthranchored' at one of its ends adjacent. the. vertex. of said. acute angle and mounted at theother of its ends .to one of, the links ofsaidtoggleunit'spaced outwardly in the plane of movement; of said toggle unit. from. a line. passing through the hinge point of..said toggleunit and the end of' said link away from said hinge point. op'erablefor causing said toggle unit toopen 'andclose whereby said conveyor bed mg" leg. pivotally mounted. in fixedrelation to. the

may be caused to change its angle of elevation between the limits of horizontal and 75.

h l. An adjustable stand for a conveyor as described in claim 3 in which: the spacing between the point of pivotal attachmentof the supporting leg and the point of pivotal attachment of said second link to said supporting leg is equal to the spacing between the point of pivotal attachment of said first link to said conveyor bed "and the point on said conveyor bed in a plane including the point of pivotal attachment of said "first link to said conveyor bed and parallel to the longitudinal plane of the conveyor bed closest "to the point of pivotal mounting of said supporting leg.

5. An adjustable stand for a conveyor as described in claim 3 in which: the point of pivotal im'o'unting of the leg is spaced from the point on said conveyor bed in a plane including the point ,jof" pivotal attachment of said first link to said fconveyor bed and parallel to the longitudinal "plane of the conveyor bed closest to the point of lpivotal mounting of said supporting leg a disi tance constituting a minor fraction of the distance between the point of pivotal attachment of jthe Supporting leg and the point of pivotal attachment of the second link to said supporting .leg.

6. An adjustable stand for a conveyor having a bed pivotally supported at one end, said stand Tcomprising: a supporting leg pivotally mounted fin fixed relation to the conveyor bed proximate :to'apoint midway between the ends of said con- .yeyor bed; a pair of link constituting a toggle fufiit, one of said links being pivotally attached to said conveyor bed substantially midway between said supporting leg and the other end of said conveyor bed, theother of said links being pivotally attached to said supporting leg at a point removed from its point of pivotal mounting; an arm on one member of said toggle unit extending ;outwardly from a line connecting the hinge point of said toggle unit and the end of said one member away from said hinge point in a direction away firm said leg when said toggle unit is in open position; a member of variable length operatively arranged for causing said toggle unit to open and close.

7. An adjustable stand for a conveyor having a bed, comprising: a supporting frame pivotally 'mounted on one of its ends in fixed relation to the conveyor bed and, on the other of its ends to floor engaging means; a pair of drag links; a pair of triangular rocker plates pivotally attached ;at one of their corners to said pair of drag links, the whole constituting a toggle unit; said drag links at the end remote from said rocker plates pivotally attached to said conveyor bed; said frocker plates at another of their corners pivotally mounted to said supporting frame; a thrust member threaded at its one end and pivotally attached at its other end to the third corner of said rocker plates and held against rotationabout its longitudinal axis; a rotatable shaft having threaded means engaging said threaded means of .,said thrust member; means for rotating said shaft; said thrust member and said shaft together constituting a member of variable length, said member of variable length in extended position holding said toggle unit open and said supporting leg and conveyor bed apart at a wide ,angle with respect to each other, and in the rertrlacted position holding said toggle unit in a closed position and said supporting leg and said conveyor bed at a small angle with respect to each other. o

8. An adjustable stand for a conveyor having a bed, comprising: a supporting frame pivotally mounted on one ,of its ends in fixed relation to the conveyor bed at a point substantially midway between the ends of said conveyor bed and on the other of its ends to floor engaging means; a pair of drag links; a pair of triangular rocker plates pivotally attached at one of their corners to said pair of drag links, the whole constituting a toggle unit; said drag links at the end remote from said rocker plates pivotally attached to said conveyor bed at a point substantially midway be tween the point of pivotal mounting of said sup porting leg and the end of said conveyor bed; said rocker plates at another of their corners pivotal- 1y mounted to said supporting frame at a point substantially removed from the end of said supporting frame pivoted to said conveyor bed; a thrust member threaded at its one end and pivotally attached at its other end to the third corner of said rocker plates and held against r0,- tation about its longitudinal axis; a rotatable shaft having threaded means engaging said threaded means of said thrust member; said thrust member and said shaft together constituting a member of variable length; means for rotating said threaded shaft for causing said member of variable length in extended position to hold said toggle unit open and said supporting .leg and conveyor bed apart at a wide angle with respect to each other, and in the retracted position to hold said toggle unit in a closed position and said. supporting leg and said conveyor bed at a small angle with respect to each other. i I

9. An adjustable support for a conveyor bed comprising: a supporting frame of fixed height and having a base of sufilcient length to give the conveyor bed longitudinal stability; said conveyor bed proximate to a point midway between its ends pivotally attached to said supporting frame; a pair of links constituting a toggle unit, one of said links being pivotally attached to said conveyor bed at a point substantially removed from said point of attachment of said supporting stand; the other of said links being pivotally attached to said supporting leg at a point removed from the point of its attachment to the conveyor bed; an arm mounted on one link of said toggle unit and extending outwardly therefrom in a direction parallel to the plane of movement of said toggle unit; a member of variable length pivotally mounted on one of its ends to said arm at a point substantially spaced from the longitudinal axis of said one link for causing said toggle unit to open and close.

10. For a platform pivotally supported at one end and having a supporting leg pivotally mounted in fixed relation to said platform supporting the other end of said platform, and adjusting means associated with said supporting leg for adjusting the height of said other end of said pivotally attached to said arm at a point substantially removed from the longitudinal axis'of 13 said one member for opening and closing said toggle unit.

11. An adjustable stand for a platform, comprising: a supporting frame on one of its ends pivotally mounted in fixed relation to said platform and, on the other of its ends to floor engaging means; a pair of drag links; a pair of tri angular rocker plates pivotally attached on one of their corners to said pair of drag links, the whole constituting a toggle unit; said drag links at the end remote from said rocker plates pivotally attached to said platform; said rocker plates at another of their corners pivotally mounted to said supportin frame; a, thrust member threaded at its one end and pivotally attached at its other end to the third corner of said rocker plates and held against rotation about its longitudinal axis; a rotatable shaft having threaded means engaging said threaded means of said thrust member; means for rotating said shaft; said thrust member and said shaft together constituting a member of variable length, said member of variable length in extended position holding said toggle unit open and said supporting leg and platform apart at a wide angle with respect to each other, and in the retracted position holding said toggle unit in a closed position and said supporting leg and said platform at a small angle with respect to each other.

12. An adjustable stand for a platform as described in claim 11 wherein said triangular rocker plates describe an isosceles triangle; said third corner of said triangle being the vertex between the sides of equal length of said rocker plates.

13. An adjustable stand for a conveyor having a frame and a supporting leg pivotally mounted on one of its ends in fixed relation to said frame and On the other of its ends to floor engaging means, the improvement in said stand including: a pairof links constituting a toggle unit connecting said supporting leg and said frame at points on each thereof removed from the point of pivotal mounting of said supporting leg to said frame; a member of variable length mounted for opening and closing said toggle unit; an arm on one link of said toggle unit and extending outwardly therefrom in a direction parallel to the plane of movement of said toggle unit; said member of variable length pivotally mounted on one of its ends to said arm at a point substantially spaced from the longitudinal axis of said link whereby a moment may be generated by the interaction of said arm and said member of variable length for urging said toggle unit to open when said toggle unit is closed and the links of said toggle unit are substantially parallel.

14. An adjustable stand for a conveyor as described in claim 13 wherein said member of variable length is pivotally mounted at the other of its ends to said frame adjacent said pivotal mounting of said frame and said supporting leg.

15. An adjustable stand for a conveyor described in claim 13 wherein said member of variable length at the other of its ends is pivotally mounted to said conveyor co-axially with said point of pivotal mounting of said frame and said supporting leg.

16. An adjustable stand for a conveyor having a frame, a supporting leg pivotally mounted in fixed relation to said frame and a pair of links constituting a toggle unit, the first of said links being pivotally attached to said frame at a point removed from said point of attachment of said supporting leg, the second of said links being pivotally attached to said supporting leg at a point removed from the point of its attachment to said frame, the improvement in said stand including: one of said links having a portion thereof projecting in the plane of movement of said toggle unit substantially outwardly from a line passing through the hinge point of said toggle unit and the pivotal mounting at the other of the ends of said one link; means attached to the outward end of said projecting portion of said one link for causing reciprocating rotative movement of said one link about its pivotal mounting at the said other end of said link.

ORVILLE E. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 402,807 Coffee May 7, 1889 455,355 Pitts July '7, 1891 552,716 Matthiessen Jan. '7, 1896 FOREIGN PATENTS Number Country Date 28,124 Netherlands Sept. 18, 1932

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