US2837373A - Fluid pressure actuated lifting apparatus - Google Patents

Description

FLUID PRESSURE ACTUATRD LIPTING APPARATUS Filed Aug. 31, 195s June 3, 1958 E. E. EDENFn-:LD

4 Shets-Sheet 1 INVENT OR 117f el d ATTORNEY June 3, 1958 E. E. EDENFIELD FLUID PRESSURE ACTUATED LIFTING APPARATUS Filed Aug. 31, 1953 4 Sheebs-SheerI 2 INVENTOR -'Jen//e ZJ Eff@ )ZM I ATTORNEY June 3, 1958 E. E. EDENFIELD 2,837,373

FLUID PRESSURE ACTUATED LIFTING APPARATUS Filed Aug. 31, 1953 4 Sheets-Sheet 3 IN VENT OR June 3, 1958 E. E. EDENFIELD FLUID PRESSURE ACTUATED LIFTING' APPARATUS v Filed Aug. 51, 195s 4 Sheets-Sheet 4 INVENTQR ATTORNEY United States Fatent O FLUID PRESSURE ACTUATED LIFTING APPARATUS Eli Elwood Edenfeld, Lakeland, Fla.

Application August 31, 1953, Serial No. 377,403

3 Claims. (Cl. 298-11) This invention relates to a novel lifting apparatus utilizing a fluid pressure responsive means for raising or extending a link and lever unit for elevating or displacing a load supporting member relatively to or away from, respectively, a base on which the lluid pressure responsive means and linkage unit are mounted.

More-particularly, it is an aim of the present invention to provide a novel linkage unit in combination with extensible fluid pressure responsive means for extending the linkage unit and wherein due to the location of the mounting of the uid pressure responsive means relatively to a portion of the linkage unit, a maximum extension of the linkage unit will be accomplished with a minimum extension of the fluid pressure responsive means.

Another object of the invention is to provide a linkage unit of unique construction having a unique connection to a load supporting member whereby movement of the linkage unit will effect a displacement of the load supporting member away from a supporting base of the linkage unit and will thereafter accomplish a rocking or tilting of the load supporting member relatively to the base.

Various other objects and advantages of the invention Will hereinafter become more fully apparent from the following description of the drawings, illustrating a presently preferred embodiment thereof, and wherein:

Figure l is a side elevational View of the lifting apparatus shown in a lowered or retracted position;

Figure 2 is a fragmentary side elevational View thereof shown in a raised or extended position;

Figure 3 is an enlarged fragmentary end elevational view looking from left to right of Figure l;

Figure 4 is an enlarged fragmentary plan view, partly in section, of a portion of the lifting apparatus with a major portion of the load supporting member thereof omitted;

Figure 5 is a longitudinal sectional view taken substantially along a plane as indicated by the line 5 5 of Figure 4;

Figure 6 is an enlarged fragmentary longitudinal sectional view of a portion of the apparatus showing the positions the parts assume just prior to commencement of the tilting of the load supporting member during the elevation thereof, and

Figure 7 is a fragmentary plan view of portions of the lever unit shown in fully retracted positions.

Referring more specifically to the drawings, for the purpose of illustrating one preferred application and use of the uid pressure actuated lifting apparatus, designated generally 10 and comprising the invention, a conventional truck frame or chassis has been illustrated in the drawings and is designated generally 11. The truck frame or chassis 11 includes laterally spaced longitudinally extending side beams or sills 12 to the rear portions of which are secured hanger frame members 13 which extend downwardly on the outer sides thereof to below the level of the bottom edges of said beams 12. Said beams12 and the hanger frames 13 combine to 'ffice form the base of the lifting apparatus 10 and provide a mobile base having translational movement in that the beams 12 are a part of a truck type motor vehicle. However, as the description proceeds it will become apparent that the base of the apparatus 10 could he stationary and is stationary with respect to other parts of the apparatus, hereinafter to be described, and which are movable relatively to the base 12, 13 in directions upwardly and downwardly as well as being translationally movable with the base while in either an extended position as illustrated in Figure 2 or a retracted position, as illustrated in Figure l.

The side frame members 13 are provided at their rear ends with upstanding bearing posts 14 for journalling the ends of a shaft 15 which extends therebetween. Corresponding ends of a pair of elongated levers 16 are secured to spaced portions of the shaft 15 in spaced apart relationship to one another between the bearing posts 14. A pair of links 17 are pivotally connected at corresponding ends thereof by pivot elements 18 to forward portions of the hanger frames 13. The two rigid links 17 are disposed on the outer sides of the beams 12 and hangers 13 and the pivots 18 thereof are disposed below the level of the shaft 15. The opposite ends of the rigid links 17 are pivotally connected by pivot elements 19 to corresponding ends of a pair of elongated lever arms 2i). The lever arms 20 are spaced apart a greater distance than the levers 16 and are disposed in cross relationship to said levers 16 and on the outer sides thereof. The crossed portions of the levers 16 and lever arms 20 are connected by a shaft 21 which extends through said levers and lever arms and is journalled therein. As best seen in Figure 4, a spacing sleeve 22 is preferably disposed loosely around the shaft 21 and extends between the levers 16. lf desired, said sleeve 22 may be secured at its end to the adjacent sides of the levers 16. Spacing washers 23 are interposed on the shaft 21 between the levers 16 and lever arms 2t) to prevent scraping contact of the levers and lever arms during swinging movement of said parts relatively to one another. The levers 16 and lever arms 20v are preferably formed of hollow tubing of rectangular cross section and the lower endsy of the lever arms 20 are recessed as seen in Figure 4 to accommodate the last mentioned ends of the links 17 which are pivotally connected thereto.

A shaft 24 extends across the frame 11 and is journalled adjacent its ends in bearing portions 25 of the hanger frames 13. A pair of supporting plates 26 are secured to longitudinally spaced portions of the shaft 24 between its bearings 25 in positions coplanar with one another.

A pair of fluid pressure responsive units, each designated generally 27, each comprises an elongated cylinder 28 having a closed end which is suitably secured in fiush engagement against one of the support members 26. Each cylinder 28 contains a piston, not shown, to which is connected a piston rod 29 which extends slidably through the opposite end of said cylinder. rod 29 at its outer end is provided with a loop or yoke 30, which loops or yokes turnably engage a rod 31 which extends between and is secured' to the levers 16 adjacent the pivot 21 and between said pivot and the pivot l5. A discharge end of a conduit 32 is connected to each cylinder 2S', said conduits opening into the cylinders 28 adjacent the first mentioned closed ends thereof. The conduits 32 are adapted to be connected to any suitable source of a fluid medium ,under pressure which may be supplied to the cylinders 2S for extending the rods 29 thereof. The fluid pressure suppliedk is preferably a hydraulic 1nedium but maybe compressed air, either of which medium maybe supplied from asource carried by the vehicle of which the frame 11 forms a part.

Each piston A thrust receiving member such as a load supporting member, designated generally 33 and illustrated as a truck body, is provided with a bottom or floor 34 to the underside of which is secured a pair of inwardly opening channel shaped members 35. The channel shaped members 3S are disposed longitudinally of the floor 34 adjacent its side edges. A pair of rail members 36 are likewise secured to the underside of the floor 34 and also extend longitudinally thereof. The rail members 36 are disposed adjacent to but spaced inwardly from the channel members 35. A pair of bearing members 37 are secured to the underside of the floor 34, near the rear end thereof, in transversely spaced alignment for journalling a shaft 38 which extends through the other ends of the lever arms for swingably connecting said lever arms to the load supporting member 33. As best seen in Figure 4, a shaft 39 extends longitudinally through the opposite ends of the levers 16 and is journalled therein. The shafts 38 and 39 are spaced equal distances from the pivotal connection 21 of the lever arms 2l) to the levers 16. A spacing sleeve 40 is turnably mounted on the shaft 39 between the levers 16 for maintaining said levers in properly spaced relationship to one another at their last mentioned ends. The shaft 39 eX- tends outwardly from the levers 16. A rigid link arm 41 is secured to each end of the shaft 39, said link arms being spaced outwardly a substantial distance from the levers 16 and being disposed between the channel mem- -bers andthe rails 36. A roller 42 is journalled on the shaft 39 on the inner side of and adjacent each of the link arms 41. Spacing sleeves 43 are disposed on the shaft 39 between the rollers 42 and levers 16 for positioning the rollers 42 at proper distances from said levers and directly beneath the rails 36. The link arms 41 are provided with outwardly opening arcuately shaped notches 44 at their opposite ends. Each link arm 41 has an outwardly projecting pin 45 fixed thereto adjacent the notch 44 thereof and which pins slidably engage in the channel members 35 and normally ride on the upper sides of the bottom anges thereof.

The rails 36 are provided with depending cam members 46 which are fixed thereto and extend longitudinally thereof. The cam members 46 are each provided with an inclined bottom track surface 47 which is inclined downwardly and away from the forward end of the load supporting member 33, or the end thereof located remote to the bearings 37. A pin 48 extends between each channel member 35 and the rail 36, disposed adjacent thereto, and is secured at its ends to said parts. Each pin 4S preferably carries a sleeve 49 which combines therewith to form a stop pivot for one of the link arms 41, as will hereinafter be described.

The levers 16 adjacent the pivot 15 are provided with transversely aligned upwardly opening notches 50 and the notched portions of said levers 16 are preferably reinforced by reinforcing strips 51 which are secured to the inner sides thereof below the notches 50.

The load supporting member 33, in the embodiment thereof as illustrated, includes upwardly extending side walls 52 which are ared outwardly toward their upper edges and which merge at their forward ends with theends of a front wall 53 and at their rear ends with the ends of a rear wall 54. The rear wall 54 has a relatively large opening 55 therein which is normally closed by a tailgate S6 which is hinged along its bottom edge to the rear end of the bottom 34. 'Ihe tailgate 56 may be latched in a closed position in any suitable manner as by a conventional spring projected latch bolt 57 which is carried by the tailgate and which is normally spring projected into engagement with a keeper 58, secured to the rear wall 54 above the opening 5S. A exible member 59 is preferably provided which extends downwardly from the lower end of the bolt 57 a suicient distance so that it can be engaged by an operator standing on the supporting surface of the truck or vehicle of which the frame 11 forms a part for displacing the bolt 57 downwardly to release it from the keeper S8 to permit the tailgate S6 to swing downwardly and outwardly to an open position, as illustrated in Figure 2. Suitable means for limiting the extent of opening movement of the tailgate 56 are preferably provided such as chains 60 which are attached to the upper edge of thc tailgate 56 and to the upper portion of the rear wall 54.

Assuming that the apparatus 10 is in a lowered position, as illustrated in Figure l, it will be readily apparent that the load supporting member or body 33 may be readily loaded with any suitable material and conveyed by a translational movement of the vehicle of which the frame 11 forms a part to any destination point. During loading and conveying of the material, not shown, the tailgate 56 is latched in a closed position. With the apparatus 10 in a lowered or retracted position as illustrated in Figure l, the parts previously described are positioned as illustrated in Figures l, 3, 4, 5 and 7 with the levers 16 disposed between the lever arms 20 and with the shaft 38 resting in the notches 50, so that the load supporting member or body 33 will be disposed in a horizontal position directly above and substantially parallel to the frame 11.

Assuming that it is desired to dump the load contained in the body 33 into a freight car, for example, or into a bin or other receptacle the open top of which is disposed substantially above the level of the bottom 34 when in its lowered position of Figure l, the fluid medium under pressure is supplied to the cylinders 28 for projecting the piston rods 29 outwardly therefrom from their retracted positions of Figures l and 4 to their projected positions of Figure 2. When this occurs, initial movement of the piston rods 29 outwardly of the cylinders 28 will cause the levers 16 to swing upwardly or counterclockwise about their pivot 15, as seen in Figure l, an adequate thrust being exerted by the pressure responsive means 27 due to the fact that they are pivoted at 24 substantially below the level of the pivot 15. As this occurs the pivot 21 will likewise swing upwardly in a counterclockwise direction exerting an upward pull on the lever arms 20 causing the links 17 to swing counterclockwise about their pivots 18 from their position of Figure 1 toward their position of Figure 2. The links 17 will limit swinging movement of the lever arms 20 relatively to the levers 16 during upward swinging movement of said levers 16 so that the connection of the lever arms 20 to the load supporting member 33 will elevate the rear end of said load supporting member as the levers and lever arms swing toward their positions of Figure 2. The forward end of the load supporting member 33 will be elevated by the levers 16 since the rollers 42 bear against the undersides of the rails 36. As the levers 16 swing upwardly the rollers 42 will ride along the undersides of the rails 36 from right to left of Figure l and will thereafter ride down the inclined track surfaces 47. During this movement, the pins 45 of the link members 41 will slide along the bottom anges of the channel members 35 and will additionally provide pivots to allow the link members 41 to rock relatively to the levers 16, turning with the shaft 39. As the rollers 42 approach the lower ends of the cam surfaces 47, as illustrated in Figure 6, the upper portions of the notches 44 will engage the sleeves 49 above the horizontal center thereof causing the notched ends of the link members 41 to be thereafter elevated slightly as the sleeves 49 seat in the center portions of the notches 44, as illustrated in Figure 6. This will raise the pins 45 out of engagement with the bottom flanges of the channels 35. Further upward swinging movement of the levers 16 will cause the rollers 42 to disengage the cam surfaces 47 and so that the forward end of the body 33 will thereafter be supported by the levers 16 and link members 41. The link members 41 will continue to pivot around the sleeves 49as the; levers 16 swing upwardly toward their positions of Figure2 for causing the forward end of the body 33 to be elevated relatively to the rear end thereof and so that the body 33 as it approaches its fully raised position of` Figure 2 will rock counterclockwise about the upper ends of the lever arms 2t) to assume its inclined' dumping position of Figure 2. In this position-it will be readily apparent' that when the latch 57 is released, as previously described, to allow the tailgate 56 to assume its open position of Figure 2, that the contents of the body 33 will be discharged by gravity downwardly and over the tailgate 56.

By thereafter releasing the iluid rhodium from the cylinders 28 through the lines 32, the weight of the levers and lever arms and of the load supporting member 33 will cause the parts to swing in the opposite direction and back to their lowered, retracted positions of Figure 1.

As previously pointe/d out, the pivot 24 of the fluid pressure responsive means 27 is located closer to the pivot 1S than the distance between the pivots 15 and 21 so that said means 27 swings in the same direction as the levers 16 in moving the link and lever system 16, 20, 17 and 41 from a lowered or retracted position to an extended position. Consequently, substantially less extension of the means 27 is required for extending the link and lever system than would be necessary if the distance between the pivot points and 24 was greater than the distance between the pivots 15 and 21 so that the pivot 21 would be swinging away from the pivot 24 as the link and lever system moves toward an extended position. Accordingly, by this arrangement whereby a lesser movement of the extensible means 27 is required, a much more stable structure is provided.

As clearly illustrated in the drawings, the distance between the pivots 15 and 24 is substantially less than the distance between the pivot points 15 and 31 and such that when the uid pressure responsive means is in a fully extended position and the levers 16 are in fully elevated positions, said means 'and the levers will be inclined in the same direction, as seen in Figure 2. Additionally, the lengths of the links 17, as measured between their pivots 13 and 19, is such that the links 17 cannot swing suciently about their pivots 18 in a counterclockwise direction to assume positions in alignment with the levers during movement of the link and lever system from a fully retracted position, as seen in Figure l, to a fully extended position, as seen in Figure 2.

While pairs of levers 16, lever arms 20, links 17 and link members 41 have been provided, it will be readily obvious that this is merely for the purpose of greater stability and that the link and lever system could be composed yof single elements rather than the pairs of elements. It will alsovbe apparent that the apparatus could be employed without the link members 41 and sloping track members 46 where a tilting of the load supporting member is not required. It will also be obvious that other types of load supporting members could be supported by the link and lever system and that the apparatus 10 could be arranged for movement of the link and lever system in other directions than vertically as illustrated and previously described.

Various other modifications and changes are likewise contemplated and may obviously be resorted to, without departing from the spirit or scope of the invention as hereinafter defined by the appended claims.

I claim as my invention:

1. A lifting unit of the character described comprising an elongated base, a pair of levers pivotally connected at corresponding ends thereof to said base, a pair of links pivotally connected to the base at a point spaced from the lever pivot, a pair of lever arms, pivot means connecting the levers and lever arms at points spaced from the ends thereof, corresponding ends of said lever arms being pivotally connected to the opposite ends of said links,

' pivotally connected to the base at a point spaced from f @t a load supporting member disposed abovethe base, levers and lever arms and pivotally connected adjacent one end thereof to the opposite ends .of said lever arms, rollers, means journalling the rollers on the opposite ends of lsaid levers, said rollers engaging the underside ofthe opposite end of the load supporting member vfor movement longitudinally thereof, the pivotalconnection of the lever arms to the load supporting member and the journal means of said rollers being equally spaced from thelpivot means connecting the levers and lever arms, `and .a iluid pressure responsive extensible means having one end pivotally connected to the base and an opposite end pivotally connected to the levers, the distance between the pivot of the levers to the base and the pivot ofthe uid pressure responsive means to the base being less than `the distance between the pivot of the levers to the base and said pivot or" the huid pressure responsive means to the levers whereby said iluid pressure responsive means will swing in the same direction as the levers and away from the base when moved to an extended position for swinging the levers away from the base for elevating the load supporting member, the pivot of the fluid pressure responsive means to the base being below the level of the adjacent portions of the levers when the levers are in lowermost retracted positions, rails mounted on the underside of said load supporting member and longitudinally thereof and otally connecting said link members adjacent their 'opposite ends to the load supporting member, said last mentioned ends of the link members having notches formed therein, stop members xed to the load supporting member and disposed in the path of movement of the notched ends of the link members as the load supporting member is moved to an elevated position, said rail members including inclined surfaces over which the rollers are movable away from the load supporting member, said inclined surfaces being disposed to be engaged by the rollers as said load supporting member approaches a fully elevated position for positioning the link members at an angle to the plane of the load supporting member when the notched ends of the link members engage said stop members for causing the load supporting member to be rocked on its pivotal connection with the lever arms for swinging the rails out of engagement with the rollers and for elevating the portion of the load supporting member supported by the link members relatively vto the portion thereof which is pivotally connected to the lever arms for tilting the load supporting member.

2. An apparatus as in claim 1, said means for slidably and pivotally connecting the link members to the load projecting laterally from the link members adjacent their notched ends and slidably engaging in said channels.

3. A lifting unit of the character described comprising an elongated base, a pair of levers pivotally connected at corresponding ends thereof to said base, a pair of links the lever pivot, a pair of lever arms, pivot means connecting the levers and lever arms at points spaced from the ends thereof, corresponding ends of said lever arms being pivotally connected to the opposite ends of said ers, means journalling the rollers on the opposite ends 'i of said levers, said rollers engaging the underside of the opposite end of the load supporting member for movement longitudinally thereof, the pivotal connection of the lever arms to the load supporting member and the journal means of said rollers being equally spaced from the pivot v i means yconnecting the levers and lever arms, and a uid pressure responsive extensible means having one end pivotally connected to the base and an opposite end pivotally connected to the levers, the distance between the pivot of the levers to the base and the pivot of the liuid pressure responsive means to the base being less than the distance between the pivot of the levers to the base and said pivot of the uid pressure responsive means to the levers whereby said fluid pressure responsive means will swing inthe same direction as the levers vand away from the base when moved to an extended position for swinging the levers away from the base for elevating the load supporting member, the pivot of the uid pressure responsive means to the base being below the level of the adjacent portions of the levers when the levers are in lowermost retracted positions, said load supporting member having inclined surfaces extending downwardly with respect to the load supporting member and disposed in the path of movement of said rollers as the levers are swung upwardly for .elevating the load supporting member, said inclined surfaces being engaged by the rollers as the load supporting member approaches a fully elevated position for rocking the load supporting member about its pivotal connection to the lever arms for elevating the portion of the load supporting member engaged by the rollers relatively to the portion thereof pivotally connected to the lever arms.

2,527,369 Meyer Oct. 24, 1950 Eisenberg Dec. 27, 1932

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