US2678742A

US2678742A - Industrial truck attachment

Info

Publication number: US2678742A
Application number: US257566A
Authority: US
Inventors: Zorn Wesley
Original assignee: Clark Equipment Co
Current assignee: Doosan Bobcat North America Inc
Priority date: 1951-11-21
Filing date: 1951-11-21
Publication date: 1954-05-18
Anticipated expiration: 1971-05-18

Description

May 18, 1954 w, ZORN 2,678,742

INDUSTRIAL TRUCK ATTACHMENT 5 Sheets-Sheet 1 Filed Nov. 21 1951 INVENTOR. WESL EY Z O R N May 18, 1954 w. ZORN 6 ,7

' INDUSTRIAL TRUCK ATTACHMENT Filed Nov. 21, 1951 5 Sheets-Sheet 2 y 18, 1954 w. ZORN 2,678,742

I INDUSTRIAL TRUCK ATTACHMENT Filed Nov. 21, 1951 5 Sheets-Sheet 5 ATTYS.

May 18, 1954 w, ZORN 2,678,742

7 INDUSTRIAL TRUCK ATTACHMENT Filed Nov. 21, 1951 5 Sheets-Sheet 4 [4 l7 131 132 36 33 I3 1N l5 "1 A 1 1 I i i 1 1 g I7 27 i i 28 g t 11 I2 H INVENTOR.

WESLEY ZORN BYMM' May 18, 1954 w ZORN INDUSTRIAL TRUCK ATTACHMENT 5 Sheets-She et 5 Filed NOV. 21 1951 INVENTOR. WESLEY 20 R N ATTYS.

Patented May 18, 1954 UNITED STATES TENT OFFICE INDUSTRIAL TRUCK ATTACHMENT Wesley Zorn,

Equipment Company, poration of Michigan Chicago, 111., assigncr to Clark Buchanan, Mich., a cor- 3 Claims.

My present invention relates generally to a load elevating mechanism, and, more specifically, is directed to a lift dump attachment particularly adapted for emptying a dump-bottom type hopper.

The present invention-constitutes an improvement over the liftdump attachment'forming the subject matter of the copending application of E. Ryan Backofen and Wesley Zorn, Serial-No. 260,018, filed December 5, 1951.

It is an object of my present invention to provide a lift dump attachment having a sequentially operable 1 to 1 and 2 to 1 lift.

The attachment of my present invention is particularly adapted for emptyinga dump-bottom type hopper. This type of hopper comprises a substantially rectangular body portion pivotally mounted at its rear end, about-a horizontalaxis, to a platform portion. The initially operable 1 to 1 lift is provided to break open the hopper while the 2 to 1 lift is provided to complete the opening of the hopper by causing the forward end of the body portion toswing upwardly and away from the forward end'of the platform portion.

It is another object of my present invention to provide a lift dump attachment, as noted, which is of simple construction andeconomical operation.

The lift dump attachment of my present invention comp-rises first frame means which is adapted to be secured to the load supporting carriage of an industrial truck. Slidably mounted in the first frame means is second frame means. effecting vertical movement/of the second'frame means. A carriage assembly is mounted for movement within the second framemeansand suitable stop means isprovided for causing the carriage assembly to move upwardly conjointly with the second frame means during upward movement of the latter. Sprockets are rotatably mounted to the second frame means andchains are trained over the sprockets. The chains are secured at their one ends tothe carriage assembly, and at their other endsto means slidably mounted. along the actuating cylinder, which means, in the specific embodiment'of my invention to be disclosed hereinafter, comprises a pair of slide members slidably mounted in guide tubes secured to opposite sides ofthe cylinder of the elevating hydraulic assembly.

The slide members are adapted to engage the upper cap of the cylinder of the-elevating hydraulic assembly after the second frame means A hydraulic assembly is provided for heightfor proupon continued upward movement of the secondframe means,

the chains will cause the carriage assembly to move upwardly at twice the speed that the second frame means moves,

Now, in order to acquaint those skilled in the art with the manner of constructing and'using devices in accordance with the principles of my present invention, I shall describe, in connection with the accompanying drawings, a preferred embodiment of my present invention:

In the drawings:

Figure 1 isa perspective view-of an industrial truck to which is secured, at the forward'end thereof, the lift dump attachment of my present invention;

Figure 2 is a front elevational view of the lift dump attachment-of Figure 1;

Figure 3 is a plan view of the lift dump attachment of Figure 2;

Figure 4 is a side elevational view of the'lift dum attachment of Figure 2;-

Figure 5 is a perspective view of the industrial truck of Figure l with the lift dump attachment in an elevated position;

Figure 6 is a diagrammatic frontelevational view of the lift dump attachment .with theelements thereof'being shown in the same relative position as they are in Figure 2;

Figure 7 is a diagrammatic front elevational view of the lift dump attachment with the elements thereof beingshown in the same relative position as they are in Figure 1; and

Figure 8 is a diagrammatic front elevational view of the lift dump attachmentvrith the elements thereof being shown in the same'relative position as they are in Figure 5;

Referring now to Figure 1, there is shownan industrial truck, indicatedgenerally by the reference numeral it, having a pair of drive wheels I l-disposed at the forward end thereof, and a pair of steering .wheels 12 disposed at the rear end thereof. The truck I6 is provided'with a conventional prime mover and drive means for effecting driving of the forward wheels l 1. Mounted on the truck it is an operators seat I3, and disposed forwardl" thereof is a hand steering wheel M mounted on a steering column l5 which is operatively connected in a conventionalmanner to the rear steering wheels l2. Pivotally mounted at the-forward end of the truck in is a conventional generally vertically extending mast, indicated generallyby the reference numeral I6, which comprises a pair of opposed facing, vertically extending, outer channel members l1, in which are slidably mounted a pair of vertically extending opposed facing channel members It. The outer channel members l1, adjacent their upper ends, are maintained in spaced relation by means of a brace 9. The inner slidable channel members l8, adjacent their upper ends, are interconnected by means of a cross head 26, which has suitable connection to the upper end of the piston rod 2| of a hydraulic piston and cylinder assemblly, indicated generally by the reference numeral 22. The assembly 22 is secured, at its lower end, to the outer channel members [1. Rotatably mounted on the cross head 26, about a horizontal axis, are a pair of sprocket gears 23 over which a pair of chains 24 are trained. The chains 24, adjacent their one ends, have connection to a brace member, not shown, secured to the outer fixed channel members l1, intermediate of the ends thereof. The chains 24, adjacent their other ends, are suitably connected to a load supporting carriage which is mounted for upward and downward movement within the inner channel members I8. Detachably secured to the forward surface of the load supporting carriage are a pair of vertically spaced, transversely extending, frame members or

fork bars

25 and 26.

Movement of the load supporting carriage within the inner channel members |8 is effected by selectively admitting fluid under pressure to the lower end of the cylinder of the hydraulic piston and cylinder assembly 22. In this instance, the flow of fluid under pressure to the lower end of the cylinder causes the piston rod 2| to be urged upwardly, which, in turn, causes upward movement of the inner channel members l8, cross head 20, and sprocket gears 23. As the sprocket gears 23 are moved upwardly the chains 24, which as aforedescribed, are fixed at their one ends, rotate about the sprocket gears 23 thus urging the load supportin carriage upwardly. When it is desired tolower the load supporting carriage, fluid under pressure is bled from the lower end of the cylinder of the assembly 22 thus permitting the piston rod 2| to move downwardly under the weight of gravity.

Brackets 21 are secured to the outer sides of the outer channel members l1, intermediate of the ends thereof, and pivotally mounted to the brackets 21 are hydraulic piston and cylinder assemblies indicated generally at 28 which are carried by the truck II). By the selective admission of fluid under pressure to either the forward or rear ends of the hydraulic piston and cylinder assemblies 28, the mast assembly, indicat-ed generally at l6, may be tilted either forwardly or rearwardly.

Secured to the forward surfaces of the

fork bars

25 and 26, in a manner to be described fully hereinafter, is the lift dump attachment of my present invention. The attachment is particularly adapted for use with a skid box or hopper of the character indicated generally at 3|. The hopper 3| is of the dump bottom type and comprises a substantially rectangular body portion 32 pivotally mounted at its rear end, about a horizontal axis, to a platform portion 33. The platform 33 is formed with upturned sides 34 and is supported at its rear end on a pair of legs 35. A transverse I-beam 36 is secured to the underside of the platform 33 adjacent the forward end thereof. A suitable bracket 31 is secured to the rear end of the body portion 32.

The hopper 3| is normally in the position V a horizontal plate 60 shown in Figure 1, in which position a container is defined for storing articles such as metal castings and the like. After the hopper 3| has been filled with castings, or the like, and it is desired to empty the hopper 3|, the device of my present invention is adapted to effect raising of the rear end of the body portion 32 relative to the platform 33. As shown in Figure 5, the platform 33 together with the upturned sides 34, define an inclined chute, the lower end of which may be directed toward another container or pile for conveying articles from the hopper 3| to the said container or pile.

The construction of the lift dump attachment of my present invention shall now be described in detail.

A pair of spaced vertically extendin channel members 4| and 42, c-shaped in cross section, are secured at their lower ends to the forward surfaces of the fork bars 25 and 26. The channel members 4| and 42 are maintained in proper spaced relation, at their upper ends, by means of a horizontal channel brace member 43. The channel members 4|, 42 and 43 define a first frame means. slidably mounted in the channel members 4| and 42, respectively, are

channel members

44 and 45. The inner

slidable channel members

44 and 45 are interconnected at their upper ends by a pair of spaced apart transversely extending

brace members

46 and 41. The

braces

46 and 41 are maintained in position by

spacers

48 and 49. The

channel members

44 and 45,

brace members

46 and 41, and

spacers

48 and 49 define a second frame means which is slidably mounted in the afore-described first frame means.

Vertical movement of the inner

slidable channel members

44 and 45, together with the

transverse brace members

46 and 41, is effected by means of power actuated means which preferably comprises a centrally located hydraulic piston and cylinder assembly indicated generally by the reference numeral 50. The hydraulic assembly 50 comprises a cylinder 5| which is secured, at its lower end, by bolts 52 to a plate 53 suitably secured, as by welding, to the front face of the lower fork bar 26. The cylinder support plate 53 is reinforced by a substantially triangular gusset plate 54.

The upper end of the cylinder 5| is provided with a cylinder cap 55, to which is secured, by bolts 56, a gland clamp plate 51 through which extends a piston rod 58. The upper threaded end of the piston rod 58 is secured, by a nut 59, to which is secured between the inner channel braces 46 and 41 intermediate of the ends thereof.

The hydraulic piston and cylinder assembly 50 is of the double acting type, and, thus, when fluid is admitted to the lower end of cylinder 5| the piston rod 58 is urged upwardly, thereby moving the inner slide top braces 46 and 41, together with the

inner channel members

44 and 45, upwardly. When fluid under pressure is admitted to the upper end of the cylinder and fluid is simultaneously bled from the lower end of the cylinder 5| the piston rod 58 is urged downwardly thereby causing the inner channel

top brace members

46 and 41, together with the

inner channels

44 and 45, to move downwardly within the outer channel members 4| and 42.

Mounted for upward and downward movement within the inner

slidable channel members

44 and 45 is a carriage assembly indicated generally by the reference numeral 1|. The carriage H comprises end plates 12- and 13 which are disposed respectively adjacent the

inner channel members

44 and 45. Laterally extending pin. members I4 are fixed in the carriage end plate l2 and project intothe inner channel member 44-. Rotatably mounted on the outer ends of the pin members It are rollers I5 which engage the inner surfaces of the leg portions of the inner channel member A l. Laterally extending pin members I6 are fixed in the carriage end plate 13. The outer ends of the pin members I6 project into the inner channel member t5 and rotatably mounted on the projecting ends of the pin members I6 are rollers I! which engage the inner surfaces of the leg portions of the inner channel member 55.

Thrust roller blocks '88 and I9 are secured respectively to the carriage end plates '52 and'I3. The blocks 18 and I9 extend into the

inner channel members

44 and 45 and provide support for rollers it and FM which respectively engage the eight portions of the inner channel members id and A5.

$ecured to the forward edges of the carriage end plates I2 and I3, respectively, are lift brackets 32 and 35: which extend toward each other. In terconnecting the lift brackets 82 and $3 is a transversely extending main carriage plate 83 which is secured to the

lift brackets

82 and 83 respectively by

bolts

35 and 86.

The junction of the carriage end plate I2 the lift bracket 82 is reinforced at the upper and lower ends thereof by gusset plates 88. The junction of the carriage end plate 13 and the lift bracket 82 is reinforced at the upper and lower ends thereof by gusset plates 89. W'elded to the inner channel members A l and 45, adjacent the lower ends thereof, are carriage bumper plates 9 and 9 i. The bumper plates 90' and SI act as stops for limiting downward movement of the carriage l! relative to the inner channel members M and 55.

Movement of the carriage H within the inner channel members ld and is accomplished by chain means which shall now be described in deta l. Mounted intermediate of the inner channel braces 46 and ll, on'spaced apart shafts 93 and are

compound sprockets

95 and 96. Trained over the

sprockets

95 and 96, respectively, are

compound chains 9'! and 88. The chains 9'! and 92, at their one ends, are riveted to chain anchor pins 93 and its. The chain anchor pins 89 and 595 respectively bolted to blocks HJI and I532 fixed to horizontal plates Hi3 and IM which are suitably secured to the rear surface of the carriage plate 84. The mountings of the plates I 33 and le t to the main carriage plate iii are reinforced by gusset plates I05 and N38.

The cylinder 5| of the hydraulic assembly 5 3 has secured along opposite sides thereof a pair of channel members I88 and I09. The outer ends of the leg portions of the cylinder channels its and I09 are interconnected for a portion of their length, adjacent the upper end, by closure plates ii and III. The channels Hi8 and H13 and the respective closure plates III) and II I define guide tubes for a purpose to be hereinafter described. The cylinder channels I08 and Hit terminate immediately beneath the cylinder cap and the latter covers a portion of the open section of the channels I08 and I09.

The other ends of the chains 9'! and Q8 extend downwardly into the open area of the cylinder channels I58 and its and are riveted to 'rectangu' lar members H2 and H3 which are slidably mounted in'the guidetubes defined by the channels I88 and I89 and the respective closure plates I I0 and .I I I.

The upperedge of the maincarriageplate 8% has secured to its upper edge a pair of spaced block members I26 and I2'I' which provide a journal support for a transverse shaft I28. Secured to the shaft I28, adjacent the block members I25 and I21, are a pair of J-shaped hook members I29 and I39.

A pair of L-shaped horizontally spaced load supporting'fork frames I3I and l32 are detachably secured along their verticallegs to the aforedescribed fork bars 25 and 26 immediately inwardly of the outer channelmembers 4i and Q2.

The operation of the liftdumpattachment of my present invention is as follows. When it is desired to dump the contents of a loaded hopper, the. industrial'truck ID is aligned with the hopper and the load supporting forks I3I' and I32 are inserted below the platform 33 between the legs 35. The hopper 3| is then raised to an elevated position by selectively admitting fluid under pressure to the lower end of thecylinder of the hydraulic assembly 22- of the truck mast I5. While the hopper 3i is'being elevated as a unit, the elements of the lift dump attachment remain in the positions shown inFigures 2 and 6. After the hopper 3I has been elevated to the desired height, fluid under pressureis admitted to the cylinder 5| of the hydraulic assembly 59 of the lift dump attachment which causes the inner channel top braces 46 and A? to be raised together with the inner channel'members id and 45. The carriage assembly 'II of the lift dump attachment is also raised by virtue of the stop members lit and SI engagingthe lower end. of the carriage end plates i2 and 'I3. Through the initial range of movement of the

inner slides

34 and 45, there is no relative movement between the carriage ":I and the piston rod 58 and what-I term a 1 to 1 lift is provided.

Now, during initial upward movement of the carriage ll, the hook members I29and I36 engage the bracket 3'? of the hopper 3i causing the rear end of the latter to be moved upwardly. Duringupward movement of the rear end of the body portion 32 of the hopper 3i the forward end of the body portion 32 pivots upwardly and away from the platform portion 33. It has been determined that a considerable-force is required to break open the hopper 3 I. For this reason, I have provided a liftdump attachment, as described, wherein the carriage II: carrying the lift hooks I29 and I39 moves initially at the same speed as the piston rod'58. This 1 to 1 lift, however, it continued through the entire range of travel oi the carriage I i, would require the attachment to be of considerable height. To overcome the lat ter objection, the above described chain and slide means are provided which cause the carriage 1i and lift hooks I 29 and I38 to move upwardly twice as fast as the piston rod 58, after the latter has been actuated through a predetermined range.

As the piston rod-58 .of the hydraulic assembly 553 is urgedupwardly, the chain slides I I2 and I iii move upwardly within the cylinder channels Eat and IE9, until the chain slides [I2 and I53 engage the underside of the cylinder cap 55 as shown in Figure '7. At this point, the chain slides I 12 and I it are prevented from movingfurther upwardly and a reaction'or anchor point is provided for the chains 9? and 98.

Upon further upward movement of the piston rod 58, the inner channel top braces 45 and ill continue upwardly, and since the

chains

91 and 98 are anchored at their one ends, the latter will travel over the

sprockets

95 and 95 causing the ends of the

chains

91 and 98, secured to the carriage H, to move upwardly relative to the

inner channels

44 and 45. Thus, through the final range of upward movement of the

inner channels

44 and 45, the carriage H is caused to move upwardly twice as fast as the piston rod 53 providing what I term a 2 to 1 lift. I

From the afore-described operation of the lift dump attachment of my present invention, it will be readily apparent to those skilled in the art that the attachment provides for initial high force or power and subsequent high speed hook travel. After the hopper 3| has been initially broken open, the force required to move the hopper to a full open position is less than the initial opening force required. Thus, the 2 to 1 lift provides sufficient force to complete the opening of the hopper 3| after the latter has been initially broken open. By providing a sequentially operable 1 to l and 2 to 1 lift, the overall vertical height of the attachment may be maintained at a minimum without sacrifice of operating efiiciency. The point at which the 2 to 1 lift becomes effective may be varied by altering the lengths of the chains 9'! and 98 which extend downwardly in the channels I68 and I09:

After the hopper 3| has been initially broken open, upward movement of the rear end of the body portion 32 causes the forward end of the platform portion 33 to be drawn toward the industrial truck until the I-beam 3'5 engages the forward ends of the load supporting forks E3! and l32. At this point, the I-beam 36 acts to stop further movement of the platform 33 toward the industrial truck and the hopper 3! will assume the position shown in Figure while the elements of the lift dump attachment will assume the positions shown in Fig. 8. With the hopper 3! in this position, the contents thereof will slide downwardly from the body portion 32 along the inclined platform 33 which acts as a chute for directing the goods where desired.

The hopper 3| may be emptied at any predetermined height within the capacity of the mast l6 of the industrial truck 10. After the hopper 3! has been emptied, fluid under pressure is selectively admitted to the upper end of the cylinder El and fluid is simultaneously bled from the lower end thereof thereby permitting the piston rod 58 to move downwardly at which time the hopper 3| will return to the position shown in Figure 1.

Now, while I have shown and described what I believe to be a preferred embodiment of my present invention, it will be understood that various modifications and rearrangements may be made therein without departing from the spirit and scope of my invention.

I claim:

1. For use with an industrial truck having an upwardly and downwardly movable load supporting carriage, the combination of a load elevating mechanism comprising, first frame means secured to said load supporting carriage, second frame means slidably mounted in said first frame means, a hydraulic assembly having a cylinder secured to said carriage and a piston rod secured to said second frame means, said cylinder having a cap at the upper end thereof, a carriage assembly mounted for movement with said second frame means, means for causing said carriage assembly to move upwardly conjointly with said second frame means during initial upward movement of the latter, channel members secured to opposite sides of said cylinder, sprogkets rotatably carried by said second frame means, chains trained over said sprockets and secured at their one ends to said carriage assembly, slide members secured to the other ends of said chains and being slidably mounted in said channel members, and said slide members being adapted to engage the cylinder cap after said second frame means has been raised a predetermined height for providing reaction points whereby upon continued upward movement of said second frame means said chains will cause said carriage assembly to move upwardly at a greater speed than the speed that said second frame means moves.

2. For use with an industrial truck having an upwardly and downwardly movable load supporting carriage, the combination of a load elevating mechanism comprising, first frame means secured to said load supporting carriage, second frame means slidably mounted in said first frame means, a hydraulic assembly having a cylinder secured to said carriage and a piston rod secured to said second frame means, said cylinder having a cap at the upper end thereof, a carriage assembly mounted for movement within said second frame means, stop means secured to the lower end of said second frame means which engage said carriage assembly during initial upward movement of said second frame means for causing said carriage assembly to move upwardly conjointly with said second frame means, guide tubes secured to opposite sides of said cylinder, sprockets rotatably carried by said second frame means, chains trained over said sprockets and secured at their one ends to said carriage assembly, slide members secured to the other ends of said chains and being slidably mounted in said guide tubes, the external peripheries of said slide members conforming to the internal peripheries of said guide tubes, and said slide members being adapted to engage the cylinder cap after said second frame means has been raised a predetermined height for providing reaction points whereby upon continued upward movement of said second frame means said chains will cause said carriage assembly to move upwardly at twice the speed that said second frame means moves.

3. For use with an industrial truck having an upwardly and downwardly movable load supporting carriage, the combination of a load elevating mechanism comprising, a first pair of spaced vertically extending channel members secured to said load supporting carriage, a second pair of channel members slidably mounted in said first channel members, a crosshead extending transversely of the industrial truck and interconnecting said second channel members adjacent the upper end thereof, a hydraulic assembly having a cylinder secured to said carriage and a piston rod secured to said cross-- head, said cylinder having a cap at the upper end thereof, a carriage assembly mounted for movement within said second channel members, stop members secured to the lower ends of said second channel members which engage said carriage assembly during initial upward movement of said second channel members for causing said carriage assembly to move upwardiy conjointly with said second channel members, vertically extending guide tubes secured to opposite sides of said cylinder, sprockets rotatably carried by said crosshead, chains trained over said sprockets and secured at their one ends to said carriage assembly, slide members secured to the other ends of said chains and being slidably mounted in said guide tubes, the outer peripheries of said slide members conforming to the inner peripheries of said guide tubes, and said slide members being adapted to engage the cylinder cap after said second channel members have been raised a predetermined height for providing reaction points whereby upon continued upward movement of said second channel members said chains will cause said carriage assembly to move upwardly at twice the speed that said second channel members move.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Howell Nov. 5, 1940 Eaton July 27, 1943 Riemenschneider et a1 July 13, 1948 Ulinski May 29, 1951 Herman Aug. 12, 1952