US3332715A

US3332715A - Attachment for lift trucks and the like

Info

Publication number: US3332715A
Application number: US477276A
Authority: US
Inventors: Richard B Hickman; Kenneth H Mindrum
Original assignee: Clark Equipment Co
Current assignee: Doosan Bobcat North America Inc
Priority date: 1965-08-04
Filing date: 1965-08-04
Publication date: 1967-07-25
Anticipated expiration: 1984-07-25

Description

July 25, 1967 R. B. HICKMAN ET AL 3,332,715

ATTACHMENT FOR LIFT TRUCKS AND THE LIKE Filed Aug. 4, 1965 INVENTORS KENNETH H. MINDRUM RICHARD B. HICKMAN ATTORNEY United States Patent 3,332,715 ATTACHMENT FOR LIFT TRUCKS AND THE LIKE Richard B. Hickman and Kenneth H. Mindrum, both of Battle Creek, Mich., assignors to Clark Equipment Company, a corporation of Michigan Filed Aug. 4, 1965, Ser. No. 477,276 9 Claims. (Cl. 294-64) This invention relates to vacuum apparatus for lifting and transporting articles of commerce, particularly paper rolls, such as heavy rolls of newsprint paper, kraft paper, and the like.

Different constructions of vacuum apparatus for handling cylindrical articles, particularly paper rolls, are known. Such apparatus has been generally found in the form of article handling attachment devices for use with industrial lift trucks, and the present invention is concerned with improvements in the construction of such devices.

One of the major problems encountered in the design of such attachment devices concerns the provision of an article engaging member capable of adjustment to rolls of different diameters while maintaining with the roll engaged one or more sealed chambers to be evacuated so that the paper roll or other article is held in position on the apparatus by atmospheric pressure. Generally, a plurality of articulated article engaging pads have been utilized which are capable of pivotal self-adjustment so as to substantially conform to the curvature of rolls having different diameters. It is a principal object of the present invention to provide an improved flexible article engaging means mounted in a manner to permit conformance to the curvature of rolls of different diameters.

Another object of the invention is to provide an improved vacuum apparatus which can effectively engage and lift a load without accurate alignment between the load and the apparatus, and which is so constructed that it can adapt itself to a roll and the position of the roll Without accurate alignment of the roll engaging portion of the vacuum apparatus with the side of the roll.

Another object is to provide a versatile, easily controlled and relatively low cost attachment for industrial trucks and the like, which will effectively adapt itself automatically to various size rolls of paper and similar cylindrical objects over a relatively wide range of sizes.

Additional objects and advantages of the invention will become apparent to persions skilled in the art from the following description and accompanying drawings, where- FIGURE 1 is a broken-away side elevational view of an industrial truck having the present vacuum apparatus mounted on the upright thereof and showing the apparatus prepared to lift a roll of paper or other cylindrical object;

FIGURE 2 is a plan view of the article engaging portion and mounting therefor of the vacuum apparatus in engagement with a roll of relatively large diameter;

FIGURE 3 is similar to FIG. 2 but shows the apparatus in engagement with a roll of relatively small diameter; and

FIGURE 4 is an enlarged fragmentary plan view of one side portion of the flexible article engaging means.

Referring now in detail to the drawings, numeral designates the forward portion of an industrial truck having a pair of front Wheels 12, a steering mechanism 13, a tiltable upright construction 14 of known construction mounted at the lower end thereof on the drive axle for the wheels 12, and a carriage mechanism 16 roller mounted on the upright 14 in known manner for elevation relative thereto and on which is mounted the apparatus 18 of the present invention.

Attachment 18 is mounted upon carriage 16 by con- 3,332,715 Patented July 25, 1967 ventional brackets 20. A turntable or support plate 22 is preferably mounted for rotation through at least by an actuating mechanism indicated generally at 24, located intermediate support plate 22 and a plate 26 to which brackets 20 are secured. An upper vacuum reserve tank 28 is mounted upon and extends transversely of plate 26 and an upper plate 30. A lower vacuum reserve tank 32 is secured to plate 26. A suitable mechanism for rotating plate 22 is described and claimed in Patent No. 3,198,023, issued Aug. 3, 1965. It consists generally of a pair of

hydraulic cylinders

34 and 36, each having a piston therein with a rack on the inner edge for engaging the teeth on a pinion, not shown, so that movement of the pistons in opposite directions in one sense rotates the pinion which is rigidly secured to plate 22 by a ring of bolts, and thus rotates the plate to various angular positions as required for rotational positioning of the paper roll 40. The cylinders are mounted in a cover plate 42 adjacent each of the cylinder ends, which are secured to

transverse backing plates

44 and 46, which in turn are secured to base plate 26. A vacuum conduit, not shown, extends through an axial opening in the rotator assembly 24 and is connected to a conduit 48 of a vacuum filter assembly 50 mounted upon the front side of support plate 22, and a conduit 52 is connected to the filter 50 and to a central opening 53 formed in a flexible load engaging base plate member 54 of this invention. A vacuum pump and controls therefor, not shown, are adapted to evacuate

reservoirs

28 and 32 and a chamber formed between the surface of roll 40 and roll engaging member 54, in a manner to be explained, Whenever a roll 40, or the like, is in sealing relation with member 54.

The structure described above, except load engaging member 54, is known and does not form a necessary part of the present invention, and so has been described in general background terms which will sufiice for the present purpose. It will be understood, for example, that it is not necessary to the practice of the present invention to utilize it with either the truck 10 or with rotating mechanism such as is described generally above. The present invention, as best shown in FIGS. 24, may be utilized with any means for supporting the same, such as exemplified by the lift truck shown in FIG. 1, and with a source of vacuum capable of evacuating the chamber formed as aforesaid when the member 54 engages a roll for moving the latter from one location to another. Although use of our invention in conjunction with a lift truck may best exemplify its utility, it is not intended that the invention be so limited.

Extending outwardly of support plate 22 on each side thereof are pairs of transversely spaced upper and

lower support brackets

60 and 62 each of which is connected at the outer end thereof to a pair of pivoted links 64 mounted above and below each bracket 60 by pins 66.

vSecured to member 54 in vertically spaced relation adjacent each side edge thereof is a pair of bracket members 68 to which the opposite ends of links 64 are pivoted by pins 70 so that when the member 54 is mounted from plate 22, each pair of brackets which is connected by a link 64 is located in a substantially horizontal plane. In addition, upper and lower pairs of facing

support brackets

72 and 74 are secured to the front side of plate 22 and the rear side of member 54 in the center section thereof, which pairs of adjacent brackets are connected together by means of a four-bar or parallelogram linkage 76, one corner portion of which is pivotally mounted upon .one of the brackets 72 and the opposed corner portion of which is pivotally mounted upon the adjacent bracket 74.

Load engaging member 54 comprises a curved platelike, semi-rigid flexible member, which may be constructed, for instance, of a reinforced rubber-like material, such as rubber reinforced with cord or fabric 'as, for

example, in the side wall construction of automotive tires. An important factor is that the material be sufficiently rigid to avoid collapsing under capacity loads for which it is designed to carry, and yet be sufliciently flexible so that it may flex a substantial amount in the direction of the curvature of the roll to be engaged thereby; i.e., substantially rigid in the direction transverse to the curvature thereof, and relatively flexible in the direction of the curvature of the member.

In order to rigidify the member 54 in a direction transverse to the curvature thereof, we have provided T-section metal beams 78 embedded within an enlarged portion '80 at each side of member 54. The brackets 68 extend into slots formed within each enlarged portion 80 and are secured, as by welding, to the beams 78. The member 54 is preferably prestressed so that the curvature thereof comprises a segment of a circle which is substantially less than a semi circle when the member is flexed into a position of maximum curvature for handling the smallest diameter roll within the range of rolls which the device is designed to handle. An outwardly extending flexible sealing lip or edge 82 is formed integral with member 54 and extends around the entire periphery thereof so that when a roll is engaged a seal is formed with the surface of the roll; a corrugated section 84 is formed on the inside curved surface of member 54 and extends around the periphery thereof adjacent sealing lip 82. The purpose of the corrugated section 84 is to insure that upon engagement with a roll a closed and sealed chamber will be formed between the adjacent curved surfaces of the member 54 and the roll having a depth equal to or somewhat less than the chamber depth shown in FIG. 4 at numeral 86, thereby insuring that the adjacent surfaces of the roll and member 54 will not be in contact which would inhibit the application of full vacuum to support the roll thus engaged. In other words, corrugated section 84 insures themaintenance of an adequate depth of the chamber to be evacuated so that when the operator actuates a vacuum control valve to communicate opening 53 with the vacuum pump and

reservoirs

28 and 32, chamber '86 will be substantially instantaneously evacuated, and the roll engaged with full vacuum pressure.

It will be noted in FIG. 2 that a roll of relatively large diameter is engaged by member 54, and in FIG. 3 a roll of relatively small diameter is thus engaged. The member 54 is preferably prestressed so that in an unflexed condition the member 54 has a curvature slightly greater than, or a radius slightly less than, that of the smallest diameter roll which it is designed to engage. When the lift truck of FIG. 1, for example, moves the article engaging attachment into position to handle a small diameter roll, such as shown in FIG. 3, member 54 is flexed a slight amount outwardly upon the application of force between member 54 and the roll so that the curvature of member =54 conforms to that of the roll and a sealing relation is established between the surface of the roll and the inner peripheral surface of lip 82, whereupon the application of vacuum to the sealed chamber formed between the roll and member 54 effects the instantaneous engagement of the roll for lifting and transporting it. In the assumed condition of handling a roll of small diameter the parallelogram linkage '76 is flexed slightly so that the corner portions thereof connected to

brackets

72 and 74 move somewhat further apart as the opposite corner portions move slightly together and the outer ends of links 64 move outwardly during the movement of member '54 into conforming surface engagement with the roll.

In *FIG. 2 a roll of relatively large diameter is shown engaged by our device, which has been actuated with some force into the side surface of the roll so that member 54 is flexed to conform to the curvature of the larger roll diameter, at which point lip 82 forms a seal with the roll and the opposed corner portions of parallelogram linkages 76 are actuated further in the directions previously noted and assume a position as illustrated in FIG. 2,

with pairs of links 64 pivoting further outwardly, as shown. The application of vacuum pressure to the abovementioned chamber formed between the roll and member 54 secures the larger roll to the device in the same manner as described above with respect to FIG. 3.

During all load handling operations, it will be noted that T-section beams 78 rigidify member 54 in the direction indicated so that it is relatively inflexible in a direction transverse to the curvature thereof, which is desirable. To disengage the roll a control valve, not shown, is opened to permit the pressure in the aforementioned chamber to increase to atmospheric pressure, whereupon the load is released.

From the foregoing it will be appreciated that our device provides an improved means of engaging various sizes of cylindrical objects, such as rolls of paper, with a single semi-rigid flexible gripper pad in accordance with our invention, and that the means for mounting the gripper pad on support plate 22 enables it to conform to rolls which vary considerably in diameter.

While the present device has "been illustrated primarily in connection with paper rolls, it may be used equally satisfactorily in handling any cylindrical objects of substantially the same size and shape as paper rolls. Further, although we have described and illustrated only one embodiment of our invention, it will be apparent to those skilled in the art that various changes in the structure and relative arrangement of parts may be made without departing from the scope of our invention.

We claim: v

1. A vacuum actuated roll handling device comprising load engaging flexing base plate means prestressed to provide a curvature in one direction having a predetermined radius smaller than the radius of the largest roll to be engaged and adaptable to increase its radius by flexing under external force imposed by engagement with a roll, a

rigid elongated member embedded in each side portion of the base plate and extending in a direction generally transverse of the curvature thereof, said base plate having a sealing lip for providing a vacuum seal with the surface of a roll engaged thereby which forms a chamber with the surface of the base plate, means supporting the base plate in such a manner that it is conformable as aforesaid to the curvature of different size rolls, and means for evacuating said chamber so that a roll may be supported by said flexing base plate.

2. A device as claimed in claim 1 wherein the sealing lip extends peripherally of said chamber, and said mounting means includes brackets secured to said rigidifying means.

3. A vacuum actuated roll handling device comprising a rigid support member, a flexible curved plate means spaced from said support member, mounting means connected to said support member and to said plate means independently at opposite side portions of the plate means and also centrally thereof, at least a portion of said mounting means being movable in both longitudinal and pivotal directions in relation to said support member during flexure of said plate means, said plate means having a curved configuration adjustable by an external force imposed on the plate means directly by a roll to be engaged from a curve of relatively small radius to one of larger radius, said plate means being adapted to engage in sealing relationship rolls of different diameters and forming therewith a sealed chamber, and means for evacuating said chamber for engaging the roll.

4. A device as claimed in claim 3 wherein rigid means extends transversely of the curvature of the plate means and integral therewith for preventing excessive flexure of the plate means in a direction transverse of the curvature thereof.

5. A vacuum actuated roll handling device comprising curved load engaging flexing base plate means having an adjustable curvature in one direction, means rigidfying opposite side portions of the flexing base plate, said rigidifying means comprising rigid elongated members embedded in each side portion of the base plate and extending in a direction generally transverse of the direction of curvature thereof, mounting means for the flexing base plate supporting the base plate for flexure such that the base plate is conformable to the curvature of rolls of different diameters engageable thereby, an endless sealing lip secured to and extending around a face of the base plate to provide a vacuum seal between the surface of a roll engaged and the surface of the base plate, and means for evacuating the chamber formed between said latter surfaces.

6. A device as claimed in claim 5 wherein said mounting means includes parallelogram linkage means connected at opposed corner portions thereof to the flexing base plate and to a mounting plate for extension and retraction with varying curvature flexure of the base plate.

7. A vacuum actuated roll handling device comprising load engaging flexing base plate means prestressed to provide a curvature in one direction having a predetermined radius smaller than the radius of the largest roll to be engaged and adaptable to increase its radius by flexing under external force imposed by engagement with a roll, means rigidifying opposed side portions of the flexing base plate in a direction generally transverse of the curvature thereof, said base plate having a'sealing lip for providing a vacuum seal with the surface of a roll engaged thereby which forms a chamber with the surface of the base plate, means supporting the base plate in such a manner that it is conformable as aforesaid to the curvature of diflierent size rolls, said supporting means including parallelogram linkage means connected at opposed corner portions thereof to the base plate and to a mounting plate for extension and retraction with flexure of the base plate, and means for evacuating said chamber so that a roll may be supported by said flexing base plate.

8. A vacuum actuated roll handling device comprising a rigid support member, a flexible curved plate means spaced from said support member, mounting means connected to said support member and to said plate means at opposite side portions of the plate means and also centrally thereof, said plate means having a curved configuration adjustable by an external force imposed on the plate means directly by a roll to be engaged from a curve of relatively small radius to one of larger radius, said mounting means including parallelogram linkage means connected at opposed corner portions thereof to the plate means and to said rigid support member for extension and retraction with varying curvature flexure of the plate means, said plate means being adapted to engage in sealing relationship rolls of different diameters and forming therewith a sealed chamber, and means for evacuating said chamber for engaging the roll.

9. A vacuum actuated roll handling device comprising a rigid support member, a flexible curved plate means spaced from said support member, mounting means connected to said support member and to said plate means at opposite side portions of the plate means and also centrally thereof, said mounting means being movable during flexure of said plate means, a rigid elongated member embedded in each side portion of the plate means and extending in a direction generally transverse of the direction of curvature of the plate means, said mounting means being connected to said member at opposite side portions of the plate means, said plate means having a curved configuration adjustable by an external force imposed on the plate means directly by a roll to be engaged from a curve of relatively small radius to one of larger radius, said plate means being adapted to engage in sealing relationship rolls of dilferent diameters and forming therewith a sealed chamber, and means for evacuating said chamber for engaging the roll.

References Cited UNITED STATES PATENTS 3,227,481 1/ 1966 Creskoff 294-64 3,227,482 1/1966 Harris 29464 3,257,141 6/1966 Buus 294-655 3,260,391 7/1966 Horton 29465.5 X 3,276,611 10/1966 Horton 214650 GERALD M. FORLENZA, Primary Examiner.

G. ABRAHAM, Assistant Examiner,

Claims

1. A VACUUM ACTUATED ROLL HANDLING DEVICE COMPRISING LOAD ENGAGING FLEXING BASE PLATE MEANS PRESTRESSED TO PROVIDE A CURVATURE IN ONE DIRECTION HAVING A PREDETERMINED RADIUS SMALLER THAN THE RADIUS OF THE LARGEST ROLL TO BE ENGAGED AND ADAPTABLE TO INCREASE ITS RADIUS BY FLEXING UNDER EXTERNAL FORCE IMPOSED BY ENGAGEMENT WITH A ROLL, A RIGID ELONGATED MEMBER EMBEDDED IN EACH SIDE PORTION OF THE BASE PLATE AND EXTENDING IN A DIRECTION GENERALLY TRANSVERSE OF THE CURVATURE THEREOF, SAID BASE PLATE HAVING A SEALING LIP FOR PROVIDING A VACUUM SEAL WITH THE SURFACE OF A ROLL ENGAGED THEREBY WHICH FORMS A CHAMBER WITH THE SURFACE OF THE BASE PLATE, MEANS SUPPORTING THE BASE PLATE IN SUCH A MANNER THAT IT IS CONFORMABLE AS AFORESAID TO THE CURVATURE OF DIFFERENT SIZE ROLLS, AND MEANS FOR EVACUATING SAID CHAMBER SO THAT A ROLL MAY BE SUPPORTED BY SAID FLEXING BASE PLATE.