Material or article handling – Apparatus for moving intersupporting articles into – within,... – Stack forming apparatus
Reexamination Certificate
2002-02-27
2003-11-11
Krizek, Janice L. (Department: 3652)
Material or article handling
Apparatus for moving intersupporting articles into, within,...
Stack forming apparatus
C414S794300
Reexamination Certificate
active
06644911
ABSTRACT:
FIELD OF THE INVENTION
The invention claimed and disclosed herein pertains to lumber stacking apparatus and more specifically, to the placement of stickers upon, and removal of stickers from, lumber stacking apparatus.
BACKGROUND OF THE INVENTION
The practice of placing milled lumber pieces, or boards, into orderly stacks of predetermined sizes has long been known to facilitate storage, transportation, and handling of the lumber. Further, the stacking of lumber pieces in certain manners is known to enhance various lumber processing operations such as lumber drying and curing and the like. Specifically, the stacking of lumber pieces, wherein the pieces are spaced apart from one another within the stack to allow for air circulation between the lumber pieces, is known to promote efficiency of lumber drying operations, and especially of operations wherein drying kilns are employed.
In relatively recent times, automatic lumber stacking apparatus have been developed to increase production capacity and efficiency, as well as to avoid the tedium and safety risk associated with the manual stacking of lumber pieces. The general nature of a typical prior art lumber stacking apparatus can be easily understood by an examination of U.S. Pat. No. 4,057,150 to Lunden. As a study of the '150 patent reveals, the operation of a typical prior art automatic lumber stacking apparatus can be generally described as in the following paragraphs in conjunction with the
FIG. 1
of the subject patent.
Referring to FIG. 1 of the '150 patent, the lumber pieces 12 to be stacked are brought into the lumber stacking apparatus 10 on a lumber in-feed conveyance means 25. The lumber in-feed conveyance means 25 can have any of a number of acceptable and known forms, including a drag-chain conveyor, for example. The lumber pieces 12 are staged and accumulated in a single-layer course at a pickup station 15 to await transfer from the pickup station 15 to a stacking station 18 where a lumber stack 16 is formed.
A fork assembly 51 lifts the accumulated course of lumber pieces 12 from the lumber conveyance means 25 at the pickup station 15 and moves the course of lumber pieces to a stacking station 18, where the course is deposited on a hoist platform 17. The course of lumber pieces 12 is typically removed from the fork assembly 51 by way of a stationery rake-off device (not shown) which is synchronously deployed relative to the movement of the fork assembly, the result of which is to strip the course off of the fork assembly as the fork assembly moves away from the stacking station 18 and back toward the pickup station 15. The prior art rake-off device will be described in further detail in later discussion.
The above-described process of moving the lumber pieces 12 from the pickup station 15 to the stacking station 18, wherein successive courses of lumber pieces 12 are placed one upon the other by the fork assembly 51, is repeated as often as necessary to form a lumber stack 16 of desired size on the hoist platform 17. The hoist platform 17 is generally configured to move the stack 16 incrementally downward in synchronous correspondence with placement of each successive lumber course thereupon so as to maintain the top surface of the stack at a substantially constant elevation relative to the path of the fork assembly 51. Upon formation of a lumber stack, the completed stack is removed from the hoist platform 17, and formation of a new stack is commenced thereupon.
As mentioned briefly above, it can be desirable to cause successive courses within a given lumber stack to be spaced apart from one another in order to promote drying processes and the like. Such spacing of successive courses of lumber within a given lumber stack is typically accomplished by placing spacers between the lumber courses that are to be spaced apart. The spacers are often in the form of relatively small lumber strips that are referred to in the art as “stickers.” While the placement of stickers during the formation of a lumber stack can be accomplished manually, it is obviously desirable to perform sticker placement automatically in conjunction with the operation of an automatic lumber stacking apparatus.
Accordingly, some prior art lumber stacking apparatus incorporate automatic sticker placers that operate in conjunction therewith to automatically form a lumber stack having spaced apart courses. Prior art sticker placers of a variety of configurations have been developed. The U.S. Pat. No. 4,253,787 to Lunden discloses at least two types of sticker placers. One type of prior art sticker placer can be understood by an examination of FIGS. 6, 7, 8, and 9 of the '787 patent. With reference thereto, a sticker in-feed conveyance means 73 is employed which can be in the form of an endless lug chain conveyor as depicted. Such a lug chain conveyor typically comprises a plurality of lugs which are spaced at predetermined intervals, the purpose of which is to facilitate control of the location of the stickers 15 on the sticker in-feed conveyance means 73.
Stickers 15 are moved from a sticker hopper (not referenced) or the like and into the pickup area (not referenced) and underneath the fork assembly 24 by way of the sticker in-feed conveyance means 73. The path of movement of the stickers 15 on the sticker in-feed conveyance means 73 is generally transverse with respect to the operational path of movement of the fork assembly 24 as well as to the movement of the lumber pieces 12 on the lumber in-feed conveyance means 18. The fork assembly 24 includes a plurality of individual fork arms 25. Each of the fork arms 25 has at least one sticker tray 84 attached thereto on which a sticker is to be placed.
A sticker transfer means 80 is employed to transfer stickers from the sticker in-feed conveyance means 73 to the sticker trays 84, wherein one sticker is placed in each of the sticker trays. The sticker transfer means 80 includes a number of frame members 87, 88 that are connected to one another in a rigid manner. The sticker transfer means 80 also includes several pairs of flat support brackets 86 that are rigidly connected to the frame members 87, and are configured to contact a corresponding sticker 15 and lift the sticker off of the sticker in-feed conveyance means 73 in response to movement of the frame members 87, 88 in an upward direction relative to the sticker in-feed conveyance means.
After the stickers 15 are lifted off of the sticker in-feed conveyance means 73 by the sticker support brackets 86, the stickers are held in a stationary position until the upward movement of the fork assembly 24 causes the corresponding sticker tray 84 to contact the respective sticker and to lift the sticker from the support brackets. After lifting the sticker 15 from the sticker transfer means 80, the fork assembly 24 then moves upwardly to contact the lumber pieces 12 which are staged thereabove upon the lumber in-feed conveyance means 18. The stickers 15 are thereby sandwiched between the respective sticker tray 84 and the lumber pieces 12 as the lumber pieces are lifted off of the lumber in-feed conveyance means 18 by upwardly movement of the fork assembly 24. The course of lumber pieces 12 is then placed upon a previously formed course of lumber pieces along with the stickers 15 which are located there between.
The sticker transfer means 80 functions by way of the frame members 87, 88 are caused to move along an arcuate path by way of a plurality of bellcranks 90 which are pivotally connected to the frame members 88 and to a shaft 89 that is rotationally supported on a framework 18. The shaft 89, in turn, is rigidly connected to a primary bellcrank 91 which is pivotally connected to a linkage 92 that is operatively supported on the framework 18. At least two shafts 89 are employed in the manner shown, wherein the shafts, together with the frame members 87. 88 and associated bellcranks 90 operate in the manner of a parallelogram four-bar-linkage.
The linkage 92 can be actuated by any of a number of actuating means, such as by way of the cam sur
Humble Erik L.
Moles Charles W.
Krizek Janice L.
Olson Thomas
Reid John S.
Reidlaw, L.L.C.
LandOfFree
Lumber stacking apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Lumber stacking apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lumber stacking apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3165594