US 3263599 A
Description (OCR text may contain errors)
Aug. 2, 1966 c. G. DICKENS PALLETIZED LOAD STRAPPING METHOD Filed May 24. 1965 United States Patent 3,263 599 PALLETIZED LOAD STRAPPING METHOD Charles Garth Dickens, Saratoga, Calif., assignor to FMC Corporation, Philadelphia, Pa., a corporation of Delaware Filed May 24, 1965, Ser. No. 458,208 3 Claims. (Cl. 100-2) This invention relates to a method of strapping a load such as a large package or group of packages to a doublefaced load supporting pallet in such manner that the trap passes through the space between the two faces of the pallet. In its more particular aspects the invention is directed toward an improved method of directing the free end of a strap of indefinite length part way about the load and through the pallet.
To facilitate the movement of large loads by fork lift trucks, it is common practice to provide a load supporting pallet and to strap the load to the pallet so that the pallet and the load travel together whereby a fork lift truck may conveniently be used at various times during shipment and warehousing. Some pallets have a single face or load supporting surface mounted on short legs or runners whereby the tines of the fork lift truck may enter readily beneath the face of the pallet. Palletized loads are generally so large that one man cannot conveniently position .a strap thereabout but when a single faced pallet is used it is a relatively simple matter to provide a guide for directing the strap about the load and beneath the face of the pallet. However, another common form of pallet, the so-called double-faced consists of two faces or load supporting surfaces spaced apart by short posts or runners and with this type it is desirable for the straps to extend through the pallet between the two faces so as not to obstruct the free entry of the tines of the fork lift truck. Actually getting the strap through the pallet considerably complicates the strapping operation and it is toward a method of strapping loads to this type of pallet that the present invention is directed.
It is therefore an object of this invention to provide an improved method of strapping a load to a doublefaced pallet.
A further object of the invention is to provide a method of positioning a strap about a load and through a double-faced pallet on which the load is resting, which method may be carried out with the aid of relatively simple apparatus.
Other objects, features and advantages of the invention will become apparent as the description thereof proceeds.
One form of the apparatus suitable for use in carrying out the method of the invention is illustrated in the accompanying drawing wherein:
FIG. 1 is a side elevational view of the apparatus; and
FIGS. 2, 3 and 4 are sections taken respectively along the lines 11-11, Ill--III and IV-IV of FIG. 1.
Inasmuch as the details of the apparatus may vary widely, one suitable form will be described in only a general way. As shown, such apparatus comprises a base framework including a horizontal section carrying a strap guiding chute 12 in the form of a channel which is U-shaped in cross section and which extends between spaced apart rollers of a roller conveyor 14. Chute 12 is curved upwardly .at its forward end at 16 and at its rearward end is provided with a curved segment 18 leading to a short vertical segment 20.
Extending vertically from horizontal section 10 is a rectangular standard 22 having secured to one face thereof at its lower end a plate 24 which serves to support the upwardly curved segment 18 of chute 12. A plate 26 having a flange 28 is secured to the upper portion of standard 22. Plate 2-6 is aligned with the vertical segment of chute 12 but the lower end of said plate 3,263,599 Patented August 2, 1966 "ice is spaced from the chute for a purpose presently to be explained. Normally, a door 29 secured by a hinge 31 to the vertical guide segment 20 extends between said segment and the bottom end of plate 26. Door 29, which is shown open in the drawing, is formed of a U-shaped channel member and when closed constitutes a strap guide leading into the vertical segment 20. Secured to plate 26 and extending vertically therealong is a resilient member 30 defining with the plate and with flange 28 a chute for guiding a strap 32 (see FIG. 3). When a force is exerted on the strap in the direction toward resilient member 30, said member yields to permit the strap to escape from the chute.
Extending cantilever from the upper end of standard 22 is an arm 34 carrying a strap guiding chute 36 similar to the one described above with reference to FIG. 3 and these two chutes are interconnected by a curved guide track 38. Mounted adjacent the free end of arm 34 with the lower edge of its periphery aligned with the end of guide chute 36 is a strap feed roller 40 which is continuously driven in a counterclockwise direction from a motor 42 through a belt 44. A lever 46 carrying a roller 48 is pivotally mounted on arm 34 at 50 and when it is desired to feed the strap 32 (which extends from a roll or other supply of indefinite length) the end of the strap is inserted into guide chute 36 and lever 46- is swung upward so as to drivingly pinch the strap between rollers 40 and 48 whereby the strap is push-fed along arm 34, down the standard 22 and through the lower strap guide chute 12. When the end of the strap emerges onto the curved end 16 of the lower strap guide chute, the operator releases lever 46 to thereby relieve the pressure on the strap between rollers 40 and 48 and stop the feeding of the strap.
Secured to or mounted alongside vertical standard 22 is a horizontally extending frame 52 upstanding from which is a plate 54 carrying four freely rotatable doubleflanged wheels 56, 58, 60 and 62. A bar or lance 64 is carried by the double-flanged wheels for horizontal reciprocation. In FIG. 1, lance 64 is shown in a partially extended position but normally it is retracted so that the forward end 66 thereof is located to the right of the end of door 29 so that said door is free to swing from its closed position to the position shown in the drawing. Lance 64 is aligned With the door whereby when the door is open, the lance may be moved endwise through the door opening. A reversible motor 68 is connected through a speed reduction unit 70 to a rubber covered drum 72 the surface of which is in contact with the lower edge of lance 64 whereby the'lance may be moved in one direction or the other as desired. An air cylinder 74 has a piston connected through a link 76 to door 29 for opening and closing the door.
Secured to the upper forward edge of plate 54 is an air cylinder 78 having a piston 80 which extends through a sleeve 82 secured to the plate 26 just above the lower end of said plate and through an opening in plate 26 aligned with the sleeve. The free end of piston 80 is provided with an arm 84 extending perpendicularly thereto and said piston has a pin 86 engaged within a helical slot 88 in sleeve 82. Normally, cylinder 78 positions the piston as shown in FIG. 3 with pin 86 in the left hand end of slot 88 and with arm 84 extending vertically upward but when air is admitted to the cylinder so as to cause retraction of the piston, pin 86 rides in slot 88 to cause the piston to turn on its longitudinal axis so as to swing the arm 84 to a horizontal position. With the piston fully retracted, arm 84 pinches or grips strap 32 against the plate 26, resilient member 30 terminating above the piston so as to permit the arm to engage the strap.
The foregoing description relates to but one specific form of mechanism which may be employed in carrying out the strapping method of the present invention, which method will now be described. The load, in the form of a large object 90, or a plurality of smaller object or packages, is positioned on a double-faced pallet having an upper face 92 spaced from a lower face 94. The pallet, with the load thereon is moved along the roller conveyor 14 so as to position it beneath the arm 34. At this time of course, lance 64 is in the retracted position, door 29 is closed and the strap gripping arm 84 is in the inactive position shown in FIG. 3. As shown in FIG. 1, the opening between the two faces of the pallet is horizontally aligned with door 29. The operator then introduces the free end of strap 32 into the open end of guide chute 36 and by moving roller 48 toward roller 40 so as to pinch the strap therebetween causes the strap to be pushfed through a path extending about the top of the load, down the side of the load and beneath the pallet until the end of the strap appears at the curved forward end 16 of the lower guide chute 12. Air cylinder 78 is then ope-rated to cause the strap to be gripped by the arm 84 at a point above the opening through the pallet and air cylinder 74 i operated to open door 29 to the position shown in the drawing. Lance 64 is caused to move forward so that the end 66 thereof (which may be provided with a flanged saddle if desired) engages the strap between the lower end of the plate 26 and the upper end of the vertical guide chute segment and slidably presses a loop of the strap through the pallet. Since the strap is gripped by arm 84, that portion of the strap which was initially beneath the pallet will be drawn through the pallet as the lance is extended. After the strap is thus laced through the pallet, cylinder 78 is operated so as to cause arm 84 to release the strap. Preferably, a guide 96 is provided so that the strap will not slide over the rough edge of the lower face 94 of the pallet. When the strap end has been thus laced through the pallet, the operator grips the end of the strap and pulls upward and also grasps the strap in the vicinity of feed roller 40 and pulls downward. The tension thus exerted on the strap causes it to pull free of guide chute 36 and the vertical chute comprised of plate 26, flange 28 and resilient member 30. With the aid of a suitable tensioning tool or by hand the operator draws the strap about the load to the desired degree of tension and secures the free to the part which was drawn from above. The secured strap is then cut away from the supply.
Having thus described the invention, what is claimed is:
1. A method of strapping a load to a double-faced pallet having a lift truck fork receiving opening therethrough comprising training a flexible strap around the top of the load, vertically along one side of the load and beneath the double-faced pallet in such a way that an end portion of the strap is beneath the pallet and the portion at the top of the load extends to a supply, engaging the strap at a point horizontally aligned with the opening through the pallet, restraining the strap from movement above the point of engagement, shoving a loop of the strap through the pallet whereby the end portion of the strap is drawn through the pallet, and securing the strap about the load.-
2. A method of strapping a load to a double-faced pallet having a lift truck fork receiving opening therethrough comprising feeding a flexible strap end-wise about the top of the load, down one side of the load and beneath the double-faced pallet, gripping the strap at a point above the opening through the double-faced pallet, slidably pressing a loop of the strap through the pallet whereby the strap portion which was fed beneath 'the pallet is drawn through the pallet, and securing the strap about the load.
3. A method of strapping a load to a double-faced pallet having a lift truck fork receiving opening therethrough comprising withdrawing strap from a supply and push-feeding the same while guiding it through a path extending first horizontally above the top of the load then down one side of the load and beneath the pallet, stopping the push-feeding operation when the leading end of the strap emerges from beneath the pallet, gripping the strap at a point near and above the opening through the pallet, engaging the strap at a point horizontally aligned with the opening through the pallet and pushing a loop of the strap through the opening whereby the portion of the strap initially fed beneath the pallet is drawn through the opening, drawing the strap into engagement with the load, and securing the strap about the load.
References Cited by the Examiner UNITED STATES PATENTS 2,629,316 2/1953 Tillinghast 100-8 2,985,098 5/1961 Winkler 10025 3,052,178 9/1962 Hall 100-25 3,150,585 9/1964 Sterner 10025 3,150,586 9/1964 Snider 10025 3,213,781 10/1965 Collins et al. 10026 WALTER A. SCHEEL, Primary Examiner.