CA2388853A1 - Longitudinal breakdown apparatus for lumber stacks - Google Patents
Longitudinal breakdown apparatus for lumber stacks Download PDFInfo
- Publication number
- CA2388853A1 CA2388853A1 CA 2388853 CA2388853A CA2388853A1 CA 2388853 A1 CA2388853 A1 CA 2388853A1 CA 2388853 CA2388853 CA 2388853 CA 2388853 A CA2388853 A CA 2388853A CA 2388853 A1 CA2388853 A1 CA 2388853A1
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- Canada
- Prior art keywords
- lumber
- rake
- tier
- hoist
- stack
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
- B65G59/00—De-stacking of articles
- B65G59/02—De-stacking from the top of the stack
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
- B65G2201/00—Indexing codes relating to handling devices, e.g. conveyors, characterised by the type of product or load being conveyed or handled
- B65G2201/02—Articles
- B65G2201/0214—Articles of special size, shape or weigh
- B65G2201/0217—Elongated
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
- B65G2201/00—Indexing codes relating to handling devices, e.g. conveyors, characterised by the type of product or load being conveyed or handled
- B65G2201/02—Articles
- B65G2201/0282—Wooden articles, e.g. logs, trunks or planks
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- Stacking Of Articles And Auxiliary Devices (AREA)
Abstract
A longitudinal breakdown apparatus for lumber stacks wherein successive tiers of lumber are sequentially unstacked from a lumber stack in a substantially horizontal direction parallel with the longitudinal axis of the stacked lumber and wherein said tiers of lumber are placed side by side on a set of landing transfer chains for conveyance to a downstream process and wherein stickers are collected in a simple straightforward manner is disclosed. The unstacking of successive tiers of lumber is accomplished by the disclosed apparatus, which includes a lumber stack infeed device, a hoist, a tier rake-off device, a sticker rake-off device, a sticker collection device and a landing transfer device.
The invention may include a plurality of longitudinal breakdown apparatuses in a variety of configurations disclosed herewith for the purpose of achieving a continuous flow of lumber to said downstream process.
The invention may include a plurality of longitudinal breakdown apparatuses in a variety of configurations disclosed herewith for the purpose of achieving a continuous flow of lumber to said downstream process.
Description
:P~-~.~i LONGITUDINAL BREAKDOWN APPARATUS FOR LUMBER STACKS
Description FIELD OF THE INVENTION
This invention relates to an apparatus for breaking down stacked lumber packages one tier at a time such that each successive tier of lumber may be collected on a conveyor for further processing, and in particular relates to an apparatus capable of removing the uppermost tier of lumber in a generally horizontal plane and feeding the uppermost rier in a direction parallel with the longitudinal axis of the lumber, and further relates to a sticker collecting method which is dependent on the feeding of each tier in a longitudinal direction.
BACKGROUND OF THE INVENTION
In the prior art, to break down a stack of solid stacked or stidcered lumber (hereinafter referred to as a lumber stack), a lumber stack is conveyed to a position above the hoist knees of a rotatable hoist frame (hereinafter refen~ed to as a tilt hoist) so that the longitudinal axis of the lumber is perpendicular to the conveyed direction and one side of the lumber stack along the longitudinal direction of the lurr>ber comes to rest adjacent to a vertical platform integral with the rotatable tilt hoist frame. The tilt hoist frame rotates to an incined p~ition, typically approximately 45 degrees, tilting the lumber stack to rest against the now inclined platform, and allowing the tilt hoist knees to raise the lun~er stalk on the incline until the uppem~ost tier passes the top edge of the inclined platfiorm and the uppermost tier then slides by gravity doom a set of slads onto a set of spill transfer chains such that the lumber lies flat on the spill transfer chains, edge to edge, in a single layer, approximately perpendicular to the direction of travel of the spilt transfer chains. As the uppermost tier slides down from the inclined lur~er stalk, the stickers beneath the uppermost tier slide down in concert with the uppermost tier, and the stickers are guided into spaces between the spill transfer chains and into a stick conveyor. The stickers must rotate by approximately 90 degrees on their longitudinal axes so as to be aligned lengthwise approximately parallel with the direction of travel of the stick conveyor.
Prior art patents are well ated in Canadian Patent CA 2230464, Newnes, and do not bear repetition herewith.
Other prior art consists of a non-tilting hoist with an overhead rake-off device (hereinafter referred to as a crib unstadcer) in which successive tiers of lumber are dispensed from the top of a lumber static in a lateral direction, that is, the lumber is discharged sideways onto a set of inclined skids and subsequently slides by gravity onto a set of spill transfer chains in a similar manner to that which occurs with a tilt hoist, while the leading ends of the stickers rest on top of the tier and are engaged between pinch rollers which then propel the stickers in a longitudinal direction with respect to the longitudinal axes of the sticks onto a pair of stick transfer chains to be collected for re-use. Crib unstadcers have a tendency to cause the lumber of the discharged tier to roll or overlap under the laterally compressive force of the rake-off lugs, thus commonly requiring intervention by an operator resulting in lost production and a risk of personal injury. Lumber stacks without stickers separating the tiers (hereinafter referred to as solid lumber stacks) cannot be unstacked reliably by a crib unstacker because without stickers to act as slideways, the lumber of the uppermost tier can catch on thicker lumber of the next uppem~ost tier as the uppermost tier is positively moved in the lateral direction of discharge by engagement with the rake-off lugs, resuming in potentially violent bunching of the lumber of the uppermost tier.
In a tilt hoist the spilling of lun~er from the top of a tilted package is susceptible to uncontrolled rolling and subsequent bunching of lurnber as a result of non-uniform coefficient of friction between successive tiers which allows some tiers to accelerate more quickly than other tiers. Because lumber stacks rnay be stored outdoors in wet and cold weather, ice can form between the lumber and the stickers causing the uppermost tier to fail to slide by the force of gravity alone. On a tilt hoist solid lumber stacks can be ;l.
unstacked in a clurr~y manner where the catching of lumber between tiers causes partial tiers to remain on the tilted lumber static unfit the pafial tiers become unstable enough to slide or roll in the lateral discharge direction. In a tilt hoist, both solid lumber stacks and frozen lumber stacks demonstrate a tendency for the lumber of the discharged tier to roll or bunch up, thus commonly requiring intervention by an operator resulting in production ins and a risk of personal injury.
In a tilt hoist the stickers are collected lengthwise in a narrow conveyor in a substantially random spaang. In order to collect the stickers into bunks fior storage and transport for re-use, they are typically conveyed to a landing transfer or unscrambler on which they are even ended and re-aligned side to side and transferred to a bunk loading location. h is common for the sticks to undergo several changes in direction and to require considerable intervention from operating personnel to keep the sticks fl~ving steadily.
When a tilt hoist or a crib unstacker discharges the last tier of lumber from the lumber static, the hoist n~tums to a re-loading position to receive another lumber static and return to the position of discharging the first tier from the new lumber static. The time for loading a new lumber stacc oonstihrtes a signficant intienupfion of the lumber flow to downstream processes. One means of maintaining lumber flow to downstream processes incorporates a lengthy series of lumber transfiers on which a large volume of Lumber is accumulated between the breakdown device and the downstream process. When the breakdown device is re-loading a lumber stack, the accumulated lumber allows the downstream process to continue without interruption. When the breakdown device resumes discharging of lumber, the accumulation ~ansfer speeds are increased to allow the lumber from the new lumber static to catch up with the previously accumulated lumber before the downstream process has consumed all of the previously aarumulated Lumber.
Alternatively, various versions of auxiliary hoists have been presented in the prior art to maintain a continuous flow of lumber to a downstream process. tn a tilt hoist, an auxiliary hoist may be mounted on the lower side of the tilted lumber static (Johnson), or on the upper side of the filfied lumber static (Hoilstrom, Ritola and Ne"mes).
Mounting an auxiliary hoist on the lower side results in a compact support frame, but the limited space on the lower side of the tilted lurr~er stack results in mechanical design compromise and difficult access for maintenance. Mounting an auxiliary hoist above the i~lted lumber stack results in either a very large support structure or complex articulating mechanism for the auxiliary hoist knee supports. Additionally, the lifting force on overhead auxiliary hoist knees is entered closer to the tips of the cantilevered knees, thus requiring greater strength in the auxiliary hoist mechanism and stnrcture.
The following list of United States and foreign patents include prior art relevant to this invention:
U.S. Patent Documents 4640655 Jacobson 4838748 Johnson 5249915 Ritota 5879129 Newnes Foreign Patent Documents 392453 Hollstrom, Sweden SUMMARY OF THE INVENTION
The Longitudinal Breakdown Apparatus for Lumber Stacks cx~mprises:
a support frame;
an infeed transfer means;
a lumber stack hois5ng means;
a longitudinal tier rake-off means;
an outfeed transfier means;
a stick collecting means, and a control means to coordinate the movements of all onents as required to provide automatically sequenced opera5on based on operator inputs.
Description FIELD OF THE INVENTION
This invention relates to an apparatus for breaking down stacked lumber packages one tier at a time such that each successive tier of lumber may be collected on a conveyor for further processing, and in particular relates to an apparatus capable of removing the uppermost tier of lumber in a generally horizontal plane and feeding the uppermost rier in a direction parallel with the longitudinal axis of the lumber, and further relates to a sticker collecting method which is dependent on the feeding of each tier in a longitudinal direction.
BACKGROUND OF THE INVENTION
In the prior art, to break down a stack of solid stacked or stidcered lumber (hereinafter referred to as a lumber stack), a lumber stack is conveyed to a position above the hoist knees of a rotatable hoist frame (hereinafter refen~ed to as a tilt hoist) so that the longitudinal axis of the lumber is perpendicular to the conveyed direction and one side of the lumber stack along the longitudinal direction of the lurr>ber comes to rest adjacent to a vertical platform integral with the rotatable tilt hoist frame. The tilt hoist frame rotates to an incined p~ition, typically approximately 45 degrees, tilting the lumber stack to rest against the now inclined platform, and allowing the tilt hoist knees to raise the lun~er stalk on the incline until the uppem~ost tier passes the top edge of the inclined platfiorm and the uppermost tier then slides by gravity doom a set of slads onto a set of spill transfer chains such that the lumber lies flat on the spill transfer chains, edge to edge, in a single layer, approximately perpendicular to the direction of travel of the spilt transfer chains. As the uppermost tier slides down from the inclined lur~er stalk, the stickers beneath the uppermost tier slide down in concert with the uppermost tier, and the stickers are guided into spaces between the spill transfer chains and into a stick conveyor. The stickers must rotate by approximately 90 degrees on their longitudinal axes so as to be aligned lengthwise approximately parallel with the direction of travel of the stick conveyor.
Prior art patents are well ated in Canadian Patent CA 2230464, Newnes, and do not bear repetition herewith.
Other prior art consists of a non-tilting hoist with an overhead rake-off device (hereinafter referred to as a crib unstadcer) in which successive tiers of lumber are dispensed from the top of a lumber static in a lateral direction, that is, the lumber is discharged sideways onto a set of inclined skids and subsequently slides by gravity onto a set of spill transfer chains in a similar manner to that which occurs with a tilt hoist, while the leading ends of the stickers rest on top of the tier and are engaged between pinch rollers which then propel the stickers in a longitudinal direction with respect to the longitudinal axes of the sticks onto a pair of stick transfer chains to be collected for re-use. Crib unstadcers have a tendency to cause the lumber of the discharged tier to roll or overlap under the laterally compressive force of the rake-off lugs, thus commonly requiring intervention by an operator resulting in lost production and a risk of personal injury. Lumber stacks without stickers separating the tiers (hereinafter referred to as solid lumber stacks) cannot be unstacked reliably by a crib unstacker because without stickers to act as slideways, the lumber of the uppermost tier can catch on thicker lumber of the next uppem~ost tier as the uppermost tier is positively moved in the lateral direction of discharge by engagement with the rake-off lugs, resuming in potentially violent bunching of the lumber of the uppermost tier.
In a tilt hoist the spilling of lun~er from the top of a tilted package is susceptible to uncontrolled rolling and subsequent bunching of lurnber as a result of non-uniform coefficient of friction between successive tiers which allows some tiers to accelerate more quickly than other tiers. Because lumber stacks rnay be stored outdoors in wet and cold weather, ice can form between the lumber and the stickers causing the uppermost tier to fail to slide by the force of gravity alone. On a tilt hoist solid lumber stacks can be ;l.
unstacked in a clurr~y manner where the catching of lumber between tiers causes partial tiers to remain on the tilted lumber static unfit the pafial tiers become unstable enough to slide or roll in the lateral discharge direction. In a tilt hoist, both solid lumber stacks and frozen lumber stacks demonstrate a tendency for the lumber of the discharged tier to roll or bunch up, thus commonly requiring intervention by an operator resulting in production ins and a risk of personal injury.
In a tilt hoist the stickers are collected lengthwise in a narrow conveyor in a substantially random spaang. In order to collect the stickers into bunks fior storage and transport for re-use, they are typically conveyed to a landing transfer or unscrambler on which they are even ended and re-aligned side to side and transferred to a bunk loading location. h is common for the sticks to undergo several changes in direction and to require considerable intervention from operating personnel to keep the sticks fl~ving steadily.
When a tilt hoist or a crib unstacker discharges the last tier of lumber from the lumber static, the hoist n~tums to a re-loading position to receive another lumber static and return to the position of discharging the first tier from the new lumber static. The time for loading a new lumber stacc oonstihrtes a signficant intienupfion of the lumber flow to downstream processes. One means of maintaining lumber flow to downstream processes incorporates a lengthy series of lumber transfiers on which a large volume of Lumber is accumulated between the breakdown device and the downstream process. When the breakdown device is re-loading a lumber stack, the accumulated lumber allows the downstream process to continue without interruption. When the breakdown device resumes discharging of lumber, the accumulation ~ansfer speeds are increased to allow the lumber from the new lumber static to catch up with the previously accumulated lumber before the downstream process has consumed all of the previously aarumulated Lumber.
Alternatively, various versions of auxiliary hoists have been presented in the prior art to maintain a continuous flow of lumber to a downstream process. tn a tilt hoist, an auxiliary hoist may be mounted on the lower side of the tilted lumber static (Johnson), or on the upper side of the filfied lumber static (Hoilstrom, Ritola and Ne"mes).
Mounting an auxiliary hoist on the lower side results in a compact support frame, but the limited space on the lower side of the tilted lurr~er stack results in mechanical design compromise and difficult access for maintenance. Mounting an auxiliary hoist above the i~lted lumber stack results in either a very large support structure or complex articulating mechanism for the auxiliary hoist knee supports. Additionally, the lifting force on overhead auxiliary hoist knees is entered closer to the tips of the cantilevered knees, thus requiring greater strength in the auxiliary hoist mechanism and stnrcture.
The following list of United States and foreign patents include prior art relevant to this invention:
U.S. Patent Documents 4640655 Jacobson 4838748 Johnson 5249915 Ritota 5879129 Newnes Foreign Patent Documents 392453 Hollstrom, Sweden SUMMARY OF THE INVENTION
The Longitudinal Breakdown Apparatus for Lumber Stacks cx~mprises:
a support frame;
an infeed transfer means;
a lumber stack hois5ng means;
a longitudinal tier rake-off means;
an outfeed transfier means;
a stick collecting means, and a control means to coordinate the movements of all onents as required to provide automatically sequenced opera5on based on operator inputs.
In a first preferred embodiment, a lumber stack is transported on an infeed transfer means such as chains or rolls to a loading position above the lifting knees of the hoist so that one end of the lumber stack is adjacent to a vertical guide plate which covers the entire area of the end of the lumber stack and which extends upward to a top horizontal edge at a height so as to act as a lumber retaining surface at the discharge end (hereinafter referred to as leading end) of the lurnber stack. The lumber stack is raised by the hoist to a discharge height so that the uppern~ost tier and the layer of s~dcers directly beneath the uppem~ost tier are elevated above the lumber retaining surt'ace at the discharge end of the lumber stack, and so that the second from uppermost tier is at an elevation at which the top edge of the lumber retaining surface is between the top and bottom of the second from uppermost tier. A tier rake-off device comprising a bar attached to a pair of parallel chains and extending across the full width of the lumber stack engages the end of the upperrrwst tier opposite the discharge end (hereinafter referred to as tail end) of the uppermost tier and propels the boards toward the leading end in a lengthwise direction parallel with the longitudinal axis of the boards in the lumber stack (hereinafter refierred to as the outfeed direction). When the uppermost tier has moved some distance, the leading end of the uppem~ost tier enters the space between an upper feed roll and a lower feed roll (hereinafter referred to as upper and lower feed rolls) which extend across the full width of the uppermost tier and which are mounted so as to make compressive contact with the top and bottom surfaces of the uppem~ost tier. The upper and lower feed rolls are powered so as to assist in the translation of the uppem~ost tier as it is propelled in the discharge direction by the tier rake-off device. A third roll mounted approximately level and parallel with the upper feed roll (hereinafter referred to as a balance roll) and on the infeed side of the upper feed roll serves to support the tail end of the uppenrbst tier after the center of gravity of the uppermost tier has moved past the upper and lower feed rolls in the outfeed direction. At some point after the uppem~ost tier has entered the space between the upper and lower feed rolls, the tier rake-vff device is dis-engaged from the tail end of the uppermost tier and the uppermost tier is then solely propelled in the outfeed direcction by the upper and lower feed rolls until the uppem~ost tier has passed completely through the upper and lower feed rolls and is discharged onto a landing transfer which carries the discharged tier in a lateral direction toward a downstream process. Thus the desired advantages over prior art devices of positive tier separation and smooth controlled tier discharge of both stidcered and solid lumber stacks are achieved by the longitudinal breakdown apparatus of the present invention.
The tier rake-off device includes a set of sticker sweep fingers attached to the tier rake-off device so as to follow the tier rake-off bar by some distance and so as to engage and ~Ilect any stickers which do not remain between the uppem~ost tier and the second uppermost tier as the uppermost tier translates in the outfieed direction. The tier rake-off device and sticker sweep fingers travel at least as far as the leading end of the lumber stack at which point the stickers drop off the leading end of the lumber stack and are guided onto a stick collecting transfer. The stick collecting transfer is mounted below the landing transfer chains and transports the stickers to a stick bunk filling location.
Throughout the movement of the stickers from a location on the lumber stack to a location on the stick bunk the stickers remain in the same orientation and at no point do the stickers traslate in an endwise direction.
The tier rake-off device is attached to drive chains in such a manner as the tier rake-off device travels with the drive chains in a re-circulating pattern allowing the drive chains to always travel in the same direction with no need to travel in a reverse direction. A plurality of tier rake-off devices are attached on the drive chains so that it is not necessary for one tier rake-off device to complete the re-cirGUlation path before another tier rake-off device engages the tail end of the next uppermost tier on the lurr~er stack. Further, the tier rake-off device includes a collapsible mounting means to allow one or more tier rake-off devices to ride harmlessly on top of the next uppermost tier while another tier rake-off device engages the tail end of next uppermost tier. Thus the tier rake-off mechanism can accommodate an assortment of long and short lumber stacks with minimal decay between cycles caused by waiting time for a tier rake-off device to engage the tail end of the next uppem~ost t;er.
The tier rake-off device includes a set of sticker sweep fingers attached to the tier rake-off device so as to follow the tier rake-off bar by some distance and so as to engage and ~Ilect any stickers which do not remain between the uppem~ost tier and the second uppermost tier as the uppermost tier translates in the outfieed direction. The tier rake-off device and sticker sweep fingers travel at least as far as the leading end of the lumber stack at which point the stickers drop off the leading end of the lumber stack and are guided onto a stick collecting transfer. The stick collecting transfer is mounted below the landing transfer chains and transports the stickers to a stick bunk filling location.
Throughout the movement of the stickers from a location on the lumber stack to a location on the stick bunk the stickers remain in the same orientation and at no point do the stickers traslate in an endwise direction.
The tier rake-off device is attached to drive chains in such a manner as the tier rake-off device travels with the drive chains in a re-circulating pattern allowing the drive chains to always travel in the same direction with no need to travel in a reverse direction. A plurality of tier rake-off devices are attached on the drive chains so that it is not necessary for one tier rake-off device to complete the re-cirGUlation path before another tier rake-off device engages the tail end of the next uppermost tier on the lurr~er stack. Further, the tier rake-off device includes a collapsible mounting means to allow one or more tier rake-off devices to ride harmlessly on top of the next uppermost tier while another tier rake-off device engages the tail end of next uppermost tier. Thus the tier rake-off mechanism can accommodate an assortment of long and short lumber stacks with minimal decay between cycles caused by waiting time for a tier rake-off device to engage the tail end of the next uppem~ost t;er.
The tier rake off device is attached to two separate links of each drive chain by means of an articulated linkage so that when the leading link begins to rotate around the drive sprocket, the vertical frame of the tier rake-off device (hereinafter referred to as the rake-off lug) is pulled in the opposite direction to the direction of travel by a diagonally attached link to the trailing chain link. This is a known means of controlling the "whiplash" effect on a tall lug as the lug begins to rotate about a head sprocket.
To provide continuous operation, a second preferred embodiment of this invention comprises iwo separate longitudinal breakdown apparatuses mounted side by side, each of which is capable of operating completely independently of the other. The tiers of lumber are discharged onto a coin outfeed transfer such that while one long~udinal breakdown apparatus is occupied with the process of re-loading a new lumber stalk, the other longitudinal breakdown apparatus continues to discharge tiers of lumber onto the corrunon outfeed transfer, thus maintaining a continuous flow of lumber to a downstream process. Advantageously, a failure of either one of the fully independent longitudinal breakdown apparatuses results in only a minor loss of produk:don effik~ency while the other longitudinal breakdown apparatus may oon~nue to operate at the same effiaency as a non-continuous breakdown system.
In a third alternative embodiment of his invention, A primary hoist with retractable lifting knees is capable of raising a lumber stalk from the loading position to the position of discharging the last tier of the lumber stack. A secondary hoist with retractable knees is mounted on the opposite side of the package from the primary hoist and the secondary hoist is capable of raising a lurr>ber stalk from the loading position to the position of discharging the last tier of the lumber stalk. When the primary hoist is discharging tiers from a lumber stack and has reached a high enough elevation to clear a new lumber stalk below the primary hoist knees, a new lurr~er stack is transported by means of a roilcase into loading p~ition. The secondary hoist, descends to a lowest position and extends the secondary hoist knees into a space below the new lur~er stalk. When the last tier of lumber has been discharged from the primary hoist, the primary hoist knees retract and the secondary hoist imrne~liately raise the new lumber static to an elevation to discharge the t~rst tier from the new lurt~er stack. The primary hoist then descends to the lowest position ready for loading a subsequent lumber stack. This embodiment provides the advantages of fully continuous operation using a single infeed rollcase and a single stick collecting apparatus. This embodiment requires a greater elevation difference betv~en the infeed rollcase and the landing transfer equal to the height of the hoist knees plus the height of a partial lumber static plus dearanoe below the hoist knees at the point when a new lumber stack is able to move into the loading p~ition. This ~r~bOdiment requires the lumber stacks to be fed into loading position from an end direction only because the two hoists are kx~ted on opposite sides of the lumber stack in order that both hoists be able to pass each other in the vertical direc~on a some point in the .
In a fourth alternative continuous operation embodiment of this invention, a longitudinal breakdovm apparatus is positioned to discharge tiers of lumber onto a landing transfer and a tilt hoist is located at the infeed end of the landing transfrsr. When the ior~itudinal breakdown apparatus is occupied with the process of re-loading a new iurrtber stack, the tilt hoist discharges tiers of lumber onto the spill transfer, bus maintaining a continuous flow of lumber to a downstream process. This embodiment provides perforrnanoe advantages similar to those previously described in the descxiption of the second embodiment. However, because of the known lumber handling and sack collection difficulties associated with tik hoist operation, this attemative embodiment is best suited to an existing tilt hoist arrangement where it is desired to add continuous operating capability by means of the addition of a longitudinal breakdown apparatus.
In a faith prefierred e~n~odiment of his invention, a primary hoist with non-retracting knees descends to a lowest position so the tops of the knees are tower than the tops of the infeed rolls or chains. A lurr~er static is moved into loading position over the primary hoist knees and the primary hoist raises the lumber static to a discharge position.
T'~ers are discharged until enough of the lumber stack has been discharged so that the primary hoist has reached a hand-off elevation at which time an auxiliary hoist with retractable knees in its lowest position is able to extend the retractable knees below the partial lumber sfiack and the auxiliary hoist continues to raise the partial lumber stack until the final tiers have been discharged. While the auxiliary hoist is raising the part'al lumber static, the primary hoist returns to its lowest p~ition and a new lumber stack is translated into the loading position over the primary hoist knees. When the last tier of lumber has been discharged from the auxiliary hoist, the auxiliary hoist knees retract and the primary hoist immediately raises the new lumber static to an elevation to discharge the first tier from the new lumber static. This embodiment provides the advantage of fully continuous operation using a single infieed rollcase or chains and a single stick collecting apparatus, and further provides the ability to accept lumber stacks from either an end direction or from a side direction. This err~odiment requires a greater elevation difference between the infeed rollcase and the landing transfer equal to the height of the hoist knees plus the height of a partial lumber static plus clearance below the retractable hoist knew at the point when a new lumber static is able to move into the loading position. This embodiment is more susceptible to down time because neither the primary hoist nor the auxiliary hoist is capable of completing the discharge of a oor~lete lumber static without ~
assistance of tl~ other hoist.
It is an object of this invention to provide a breakdown apparatus for lumber stacks with the following advantages over prior art breakdown devices:
a) Positive separation of the uppermost tier from either a stidcered lumber stack or a solid lumber static using a mechanical rake~.off device to teed the uppemrost tier in a longitudinal direction.
b) Smooth tier discharge onto a landing transfer using a longitudinal discharge direction.
c) Fully continuous operation using a non-tilting longitudinal breakdown apparatus for lumber stacks in conjunction with another longitudinal breakdown apparatus for lumber stacks, or in conjunction with an auxiliary hoist, or in conjunction with an existing tilt hoist.
d) Stick collection in a more direct and controlled manner by translating the sticks from the lumber stack to the stick storage bunk in a single dir~ec~ion with minimal change in ~~. ,i.
elevation and without changing orienta5on of the sticks with respect to the longitudinal axes of the sticks.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better undersfiood by reference to the a~on~panying drawings, wherein:
FIG. 1 is a plan view according to a preferred embodiment of a non-continuous operating version of the longitudinal bn3akdown apparatus ifor lumber stacks of tt~
present invention.
FIG. 2 is an elevation viev~r along section line 2-2 in FIG. 1.
FIG. 3 is an eleva5on view along section line 3--3 in FIG. 1.
FIG. 4 is a detail view along section tine 4--4 in FIG. 1.
FIG. 5 is a plan view acxording to a prefierred embodiment of a confinuous operating version of the longitudinal broakdown apparatus for lurr>ber stalks of the pn~sent invent'ron.
FIG. 6 is an eleva5on view along section line g--6 in FIG. 5.
FIG. 7 is an elevation view along section line 3--3 in FIG. 1 depicting an alternate preferred embodiment.
FIG. 8 is an eleva~on view along section line 3--3 in FIG. 1 depicting an alternate preferred embodiment.
FIG. 9 is an elevation view along section tine 3--3 in FIG. 1 depicting an alternate preferred embodiment.
FIG. 10 is an expanded detail view al~g section line 4-4 in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
~~ x i ;
As best seen in FIG. 1, FIG. 2, FIG. 3 and FIG. 4 according to the first preferred embodiment described above of a longitudinal breakdown apparatus for lurr>ber stacks, the apparatus of the present invention includes an infead rollcase 1, a support frame 2, a primary breakdown apparatus 3, a set of landing transfer chains 4, and a stick collecting apparatus 5. A lumber stack 9 is translated longitudinally on rollcase 1 in tl~ direction of flow arrow 10 until the lumber stack reaches a loading position where the leading end of the lumber stack is adjacent to a retaining plate 11. Hoist knees 12 are at the lowest position while the lumber stack 9 is translated into a loading posfion. Best seen in FIG. 3 and FIG. 4, Hoist knees 12 are raised until the top tier of the lumber stack 9 is at a discharge position where the uppermost tier 13 and the upperr~st row of stickers 14 are at an elevation higher than the top edge of the retaining plate 11. A rake-off device 15 attached to rake-ofif chains 18 advances in an outfeed direction according to flow arrow 10 engaging the tail end of the uppermost tier 13. Uppem~ost tier 13 is thus caused to translate in the outfieed direction and the leading end of uppermost tier 13 passes between a lower feed roll 17 and an upper feed roll 18. Retaining plate 11 retains tt~
next uppermost tier to ensure that only the uppermost tier 13 and stickers 14 can move in the outfeed direction. Lower feed roll 17 and upper feed colt 18 are mounted so as to bear cxampressively upon the bottom and top surfaces of uppermost fier 13 and are powered and driven in a direction so as to assist the rake-off device 15 to translate the uppem~ost fier in the ouHeed direction. When the center of gravity of uppermost tier 13 has translated in the outfeed direction past lower feed roll 17 and upper feed roll 18, balance roll 19 bears on the top surface of uppemx~t tier 13 so as to rr~intain uppemnost tier 13 in approximately horizorrhal orientation until the tail end of uppemnost tier 13 passes balance roll 19 and the leading end of uppermost tier 13 is supported by landing chains 4 as uppermost tier 13 passes lower feed roll 17 and upper feed roll 18 to be completely discharged onto landing chains 4. Landing chains 4 run continuously in the downstream direction according to flow arrow 20. A scraping bar 21 extends across the full width of uppermost tier 13 and the scraping bar 21 is mounted upstream of the balance roll 19 so as to hold back any debris or stickers 14 which may be resting on top of the uppermost tier 13 and so as to prevent debris or stickers 14 from reaching the balance roll 19. After the tail end of uppermost tier 13 has passed the scraper bar 21, any debris held back by the L. J.. ; '" . ~ I
scraper bar 21 drops by gravity into an area between the retaining plate 11 and landing transfer chains 4. Attached to the rake-off device 15 are a set of sticker sweep fingers 22 which follow rake-off device 15. Sticker sweep fingers 22 are shaped so as to engage stickers 14 which are resting on the top surface of next fler 23 and so as to slid lightly on the flop surface of a neck tier 23 and so as to IiR mom~antarily in the event that they catch on an irresistible obstacle such as the tail end of next tier 23 or a geometric deflect on the top surface of next tier 23. Slickers 14 are thus caused to translate in the outfeed direction according to flow arrow 10 until the stickers 14 pass the leading end of lumber stack 9 and retaining plate 11 at which point the stickers 14 drop by gravity and are guided onto the stick transfer chains 24. The stickers continue to translate in the ouffeed direction according to flow arrow 10 on stick transfer chains 24 until the stickers 14 drop by gravity off the head end of stilt transfer chains 24 into sflck bunk 25.
Stick bunk 25 rests on sflck bunk chain$ 26 and is positioned bek>w the head end of stilt chains 24 so that when sticc bunk 25 is empty, stickers 14 will drop ink a beginning end of stilt bunk 25 until the sticks 14 have accumulated to a maximum height in stick bunk 25.
Stick bunk chains 26 then advance an incremental distance in the outfeed direction according to flow arrow 10 to allow further slicks 14 to be deposited into an empty space in stick bunk 25.
When a last tier 27 has been discharged, hoist knees 12 are in a highest posiflon. Hoist knees 12 are then lowered to a lowest posiflkm at which flme a new lumber stack 9 may be advanced to a loading posi5on. During the time from #re discharge of the last tier 27, until the first tier of a new lumber stalk is discharged, no further tiers may be discharged from the primary breakdown apparatus, resulting in an interruption to the flow of lumber 28 to a dov~mstream process.
As best seen in FIG. 5 and FIG. 6, a second preferred embodiment of a continuous operating longitudinal breakdown apparatus for lumber stacks, the apparatus of the present invention includes an infeed rollcase 1, a support frame 2, a primary breakdown apparatus 3, a set of landing transfer chains 4, a primary stick electing apparatus 5, a secondary infeed rollcase 29, a secondary br~akdovm apparatus 30, and secondary stidk collecting apparatus 31. During the time from tip discharge of the last bar 27 from the primary breakdown apparatus 3, unfit the first tier of a next lumber stalk 9 is discharged ~~I: ~ ~ 1. :
from the primary breakdown apparatus 3, the auxiliary breakdown apparatus 30 and the auxiliary sflck collecting apparatus 31 are activated in a similar sequence of operations as previously described in the first preferred embodiment for the primary breakdo~m apparatus 3 and the primary stick collecting apparatus 5 so as to cause tiers to be discharged from the auxiliary breakdown apparatus 30 onto the landing transfer chains 4, thus providing a continuous flow of lumber 28 to a downstream process.
As best seen in FIG. 1 and FIG. 7 a third preferred etrtbodiment of a conflnuous operaflng longitudinal breakdown apparatus for lumber stacks, the apparatus of the present invention includes an infeed rollcase 1, a support frame 2, a primary breakdown apparatus 3, a stick ~Ilecting apparatus 5, a secondary breakdown apparatus 3a (not as shown in FIG. 1), and a set of landing transfer chains 4. During the lime from the discharge of the last tier 27 from the primary breakdown apparatus 3, until the first tier of a next lumber stack is discharged from the primary breakdown apparatus 3, the secondary breakdown apparatus 3a is activated in a similar sequence of operations as previously described in the description for the first preferred embodiment for the primary breakdown apparatus 3 and the stick collecting apparatus 5 so as to cause flare to be discharged from the auxiliary breakdown apparatus 3a onto the landing transfer chains 4, thus providing a continuous flow of lumber 28 to a downstream process.
As bit seen in FIG. 1 and FIG. 8 a fourth preferred embodiment of a continuous operating longitudinal breakdown apparatus for lumber stacks, the apparatus of the present invenflon includes an infeed rollcase 1, a support frame 2, a primary breakdown apparatus 3, a primary stick collecting apparatus 5, infeed chain transfer 33 {not shown in FIG. 1), an auxiliary tilt hoist 34 (not shown in FIG. 1), a set of spill transfer chains 35 (not shown in FIG. 1), and auxiliary stick collecting apparatus 36 (not shown in FIG. 1). During the time from the discharge of the last tier 27 from the primary breakdown apparatus 3, until the first tier of a next lumber stack is discharged from the primary breakdovm apparatus 3, the auxiliary tilt hoist 34 and the auxiliary stick collecting apparatus 36 are activated in a similar sequence of operaflons as previously described for the primary breakdown apparatus 3 and the primary stick collecting apparatus 5 so as to cause tiers to be discharged from the auxiliary lift hoist 34 onto the spilt transfer chains 35, thus providing a continuous flow of lumber 28 to a downstream process.
As best seen in FIG. 1 and FIG. 9 a fifth preferred embodiment of a continuous operating longitudinal breakdown apparatus for lumber stacks, the apparatus of the present invention includes an infeed rollcase 1, a support frame 2, a tier rake-off apparatus 3b, a primary hoist 3c, a stick collecting apparatus 5, an auxiliary breakdown hoist with retrac~bie knees 37, and a set of landing transfer chains 4. The primary hoist 3c with non-retracting knees 12 descends to a lowest posfion so the tops of the knees 12 are lower than the tops of the infeed rolls 1. A lun~er stack 9 is moved into Loading position over the primary hoist knees 12 and the primary hoist 3c raises the lumber stack 9 to a discharge position. Tiers are discharged until enough of the lumber stack 9a has been discharged so that the primary hoist 3c has reached a hand-off elevation at which an auxiliary hoist 38 with nstractable knees 39 in its lowest posfion is able to extend the retra~ble knees 39 below the par5al lurr~ber stack 9a and the auxiliary hoist 37 continues to raise the partial liner static 9a as the final tiers are discharged. While the auxiliary hoist with retractable knees 37 is raising the partial turner stack 9a, the primary hoist 3c returns to its lowest position and a new lumber stack 9 is translated into the loading position over the primary hoist knees 12. When the last tier of lumber has been discharged from the auxiliary hoist knees 39, the auxiliary hoist knees 39 retract and the primary hoist 3c immediately raises the new lumber stack 9 to an elevation to discharge the first tier from the new lumber static 9, tt~us providing a continuous flow of lumber 28 to a doWmstream process.
As best seen in FIG. 10, tier rake-off assemblies 41a, 41b, and 41c are shown in three states of operation. Tier rake-of!' assembly 41 a is in the position to propel an uppermost tier 13 in the discharge direction and to engage stickers 14 with the sticker sweep arms 22. Tier rake-off assembly 41 b is in the position of resting on the top of uppemwst tier 13 with the weight of the tier rake--off assembly home by the sticker sweep fingers 22. Tier ~.~. &- . I i rake off guides 42, slidably mounted to the rake-off lugs 43, are attached to tier rake-off device 15 and are shown in an elevated position with respect to tier rake-off lug 43. Thus the tier rake-off assembly 41 b is able to rest harmlessly on top of uppem~ost tier 13. Tier rake-off assembly 41c is shown in the position of turning around the drive chain sprockets 44. Leading link 45 is pivotally attached to the top part of tier rake-off lug 43. Trailing link 48 is pivotally attached to an articulating link 47 which is pivotally attached to the bottom part of tier rake-off lug 43. The result of this mounting geometry is to cause the tier rake-off lug 43 and tier rake-off device 15 and the s5cker sweep fingers 22 to rotate in a counter clockwise direction as the tier rake-off assembly 41c begins to rotate in a clockwise direction around drive sprockets 44, thus providing the desired gentle dis-engagement of tier rake-off device 15 from uppem~ost tier 13, and further preventing the sticker sweep frngers from rotating in an interference path with uppermost tier 13.
As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modficatrons are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.
To provide continuous operation, a second preferred embodiment of this invention comprises iwo separate longitudinal breakdown apparatuses mounted side by side, each of which is capable of operating completely independently of the other. The tiers of lumber are discharged onto a coin outfeed transfer such that while one long~udinal breakdown apparatus is occupied with the process of re-loading a new lumber stalk, the other longitudinal breakdown apparatus continues to discharge tiers of lumber onto the corrunon outfeed transfer, thus maintaining a continuous flow of lumber to a downstream process. Advantageously, a failure of either one of the fully independent longitudinal breakdown apparatuses results in only a minor loss of produk:don effik~ency while the other longitudinal breakdown apparatus may oon~nue to operate at the same effiaency as a non-continuous breakdown system.
In a third alternative embodiment of his invention, A primary hoist with retractable lifting knees is capable of raising a lumber stalk from the loading position to the position of discharging the last tier of the lumber stack. A secondary hoist with retractable knees is mounted on the opposite side of the package from the primary hoist and the secondary hoist is capable of raising a lurr>ber stalk from the loading position to the position of discharging the last tier of the lumber stalk. When the primary hoist is discharging tiers from a lumber stack and has reached a high enough elevation to clear a new lumber stalk below the primary hoist knees, a new lurr~er stack is transported by means of a roilcase into loading p~ition. The secondary hoist, descends to a lowest position and extends the secondary hoist knees into a space below the new lur~er stalk. When the last tier of lumber has been discharged from the primary hoist, the primary hoist knees retract and the secondary hoist imrne~liately raise the new lumber static to an elevation to discharge the t~rst tier from the new lurt~er stack. The primary hoist then descends to the lowest position ready for loading a subsequent lumber stack. This embodiment provides the advantages of fully continuous operation using a single infeed rollcase and a single stick collecting apparatus. This embodiment requires a greater elevation difference betv~en the infeed rollcase and the landing transfer equal to the height of the hoist knees plus the height of a partial lumber static plus dearanoe below the hoist knees at the point when a new lumber stack is able to move into the loading p~ition. This ~r~bOdiment requires the lumber stacks to be fed into loading position from an end direction only because the two hoists are kx~ted on opposite sides of the lumber stack in order that both hoists be able to pass each other in the vertical direc~on a some point in the .
In a fourth alternative continuous operation embodiment of this invention, a longitudinal breakdovm apparatus is positioned to discharge tiers of lumber onto a landing transfer and a tilt hoist is located at the infeed end of the landing transfrsr. When the ior~itudinal breakdown apparatus is occupied with the process of re-loading a new iurrtber stack, the tilt hoist discharges tiers of lumber onto the spill transfer, bus maintaining a continuous flow of lumber to a downstream process. This embodiment provides perforrnanoe advantages similar to those previously described in the descxiption of the second embodiment. However, because of the known lumber handling and sack collection difficulties associated with tik hoist operation, this attemative embodiment is best suited to an existing tilt hoist arrangement where it is desired to add continuous operating capability by means of the addition of a longitudinal breakdown apparatus.
In a faith prefierred e~n~odiment of his invention, a primary hoist with non-retracting knees descends to a lowest position so the tops of the knees are tower than the tops of the infeed rolls or chains. A lurr~er static is moved into loading position over the primary hoist knees and the primary hoist raises the lumber static to a discharge position.
T'~ers are discharged until enough of the lumber stack has been discharged so that the primary hoist has reached a hand-off elevation at which time an auxiliary hoist with retractable knees in its lowest position is able to extend the retractable knees below the partial lumber sfiack and the auxiliary hoist continues to raise the partial lumber stack until the final tiers have been discharged. While the auxiliary hoist is raising the part'al lumber static, the primary hoist returns to its lowest p~ition and a new lumber stack is translated into the loading position over the primary hoist knees. When the last tier of lumber has been discharged from the auxiliary hoist, the auxiliary hoist knees retract and the primary hoist immediately raises the new lumber static to an elevation to discharge the first tier from the new lumber static. This embodiment provides the advantage of fully continuous operation using a single infieed rollcase or chains and a single stick collecting apparatus, and further provides the ability to accept lumber stacks from either an end direction or from a side direction. This err~odiment requires a greater elevation difference between the infeed rollcase and the landing transfer equal to the height of the hoist knees plus the height of a partial lumber static plus clearance below the retractable hoist knew at the point when a new lumber static is able to move into the loading position. This embodiment is more susceptible to down time because neither the primary hoist nor the auxiliary hoist is capable of completing the discharge of a oor~lete lumber static without ~
assistance of tl~ other hoist.
It is an object of this invention to provide a breakdown apparatus for lumber stacks with the following advantages over prior art breakdown devices:
a) Positive separation of the uppermost tier from either a stidcered lumber stack or a solid lumber static using a mechanical rake~.off device to teed the uppemrost tier in a longitudinal direction.
b) Smooth tier discharge onto a landing transfer using a longitudinal discharge direction.
c) Fully continuous operation using a non-tilting longitudinal breakdown apparatus for lumber stacks in conjunction with another longitudinal breakdown apparatus for lumber stacks, or in conjunction with an auxiliary hoist, or in conjunction with an existing tilt hoist.
d) Stick collection in a more direct and controlled manner by translating the sticks from the lumber stack to the stick storage bunk in a single dir~ec~ion with minimal change in ~~. ,i.
elevation and without changing orienta5on of the sticks with respect to the longitudinal axes of the sticks.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better undersfiood by reference to the a~on~panying drawings, wherein:
FIG. 1 is a plan view according to a preferred embodiment of a non-continuous operating version of the longitudinal bn3akdown apparatus ifor lumber stacks of tt~
present invention.
FIG. 2 is an elevation viev~r along section line 2-2 in FIG. 1.
FIG. 3 is an eleva5on view along section line 3--3 in FIG. 1.
FIG. 4 is a detail view along section tine 4--4 in FIG. 1.
FIG. 5 is a plan view acxording to a prefierred embodiment of a confinuous operating version of the longitudinal broakdown apparatus for lurr>ber stalks of the pn~sent invent'ron.
FIG. 6 is an eleva5on view along section line g--6 in FIG. 5.
FIG. 7 is an elevation view along section line 3--3 in FIG. 1 depicting an alternate preferred embodiment.
FIG. 8 is an eleva~on view along section line 3--3 in FIG. 1 depicting an alternate preferred embodiment.
FIG. 9 is an elevation view along section tine 3--3 in FIG. 1 depicting an alternate preferred embodiment.
FIG. 10 is an expanded detail view al~g section line 4-4 in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
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As best seen in FIG. 1, FIG. 2, FIG. 3 and FIG. 4 according to the first preferred embodiment described above of a longitudinal breakdown apparatus for lurr>ber stacks, the apparatus of the present invention includes an infead rollcase 1, a support frame 2, a primary breakdown apparatus 3, a set of landing transfer chains 4, and a stick collecting apparatus 5. A lumber stack 9 is translated longitudinally on rollcase 1 in tl~ direction of flow arrow 10 until the lumber stack reaches a loading position where the leading end of the lumber stack is adjacent to a retaining plate 11. Hoist knees 12 are at the lowest position while the lumber stack 9 is translated into a loading posfion. Best seen in FIG. 3 and FIG. 4, Hoist knees 12 are raised until the top tier of the lumber stack 9 is at a discharge position where the uppermost tier 13 and the upperr~st row of stickers 14 are at an elevation higher than the top edge of the retaining plate 11. A rake-off device 15 attached to rake-ofif chains 18 advances in an outfeed direction according to flow arrow 10 engaging the tail end of the uppermost tier 13. Uppem~ost tier 13 is thus caused to translate in the outfieed direction and the leading end of uppermost tier 13 passes between a lower feed roll 17 and an upper feed roll 18. Retaining plate 11 retains tt~
next uppermost tier to ensure that only the uppermost tier 13 and stickers 14 can move in the outfeed direction. Lower feed roll 17 and upper feed colt 18 are mounted so as to bear cxampressively upon the bottom and top surfaces of uppermost fier 13 and are powered and driven in a direction so as to assist the rake-off device 15 to translate the uppem~ost fier in the ouHeed direction. When the center of gravity of uppermost tier 13 has translated in the outfeed direction past lower feed roll 17 and upper feed roll 18, balance roll 19 bears on the top surface of uppemx~t tier 13 so as to rr~intain uppemnost tier 13 in approximately horizorrhal orientation until the tail end of uppemnost tier 13 passes balance roll 19 and the leading end of uppermost tier 13 is supported by landing chains 4 as uppermost tier 13 passes lower feed roll 17 and upper feed roll 18 to be completely discharged onto landing chains 4. Landing chains 4 run continuously in the downstream direction according to flow arrow 20. A scraping bar 21 extends across the full width of uppermost tier 13 and the scraping bar 21 is mounted upstream of the balance roll 19 so as to hold back any debris or stickers 14 which may be resting on top of the uppermost tier 13 and so as to prevent debris or stickers 14 from reaching the balance roll 19. After the tail end of uppermost tier 13 has passed the scraper bar 21, any debris held back by the L. J.. ; '" . ~ I
scraper bar 21 drops by gravity into an area between the retaining plate 11 and landing transfer chains 4. Attached to the rake-off device 15 are a set of sticker sweep fingers 22 which follow rake-off device 15. Sticker sweep fingers 22 are shaped so as to engage stickers 14 which are resting on the top surface of next fler 23 and so as to slid lightly on the flop surface of a neck tier 23 and so as to IiR mom~antarily in the event that they catch on an irresistible obstacle such as the tail end of next tier 23 or a geometric deflect on the top surface of next tier 23. Slickers 14 are thus caused to translate in the outfeed direction according to flow arrow 10 until the stickers 14 pass the leading end of lumber stack 9 and retaining plate 11 at which point the stickers 14 drop by gravity and are guided onto the stick transfer chains 24. The stickers continue to translate in the ouffeed direction according to flow arrow 10 on stick transfer chains 24 until the stickers 14 drop by gravity off the head end of stilt transfer chains 24 into sflck bunk 25.
Stick bunk 25 rests on sflck bunk chain$ 26 and is positioned bek>w the head end of stilt chains 24 so that when sticc bunk 25 is empty, stickers 14 will drop ink a beginning end of stilt bunk 25 until the sticks 14 have accumulated to a maximum height in stick bunk 25.
Stick bunk chains 26 then advance an incremental distance in the outfeed direction according to flow arrow 10 to allow further slicks 14 to be deposited into an empty space in stick bunk 25.
When a last tier 27 has been discharged, hoist knees 12 are in a highest posiflon. Hoist knees 12 are then lowered to a lowest posiflkm at which flme a new lumber stack 9 may be advanced to a loading posi5on. During the time from #re discharge of the last tier 27, until the first tier of a new lumber stalk is discharged, no further tiers may be discharged from the primary breakdown apparatus, resulting in an interruption to the flow of lumber 28 to a dov~mstream process.
As best seen in FIG. 5 and FIG. 6, a second preferred embodiment of a continuous operating longitudinal breakdown apparatus for lumber stacks, the apparatus of the present invention includes an infeed rollcase 1, a support frame 2, a primary breakdown apparatus 3, a set of landing transfer chains 4, a primary stick electing apparatus 5, a secondary infeed rollcase 29, a secondary br~akdovm apparatus 30, and secondary stidk collecting apparatus 31. During the time from tip discharge of the last bar 27 from the primary breakdown apparatus 3, unfit the first tier of a next lumber stalk 9 is discharged ~~I: ~ ~ 1. :
from the primary breakdown apparatus 3, the auxiliary breakdown apparatus 30 and the auxiliary sflck collecting apparatus 31 are activated in a similar sequence of operations as previously described in the first preferred embodiment for the primary breakdo~m apparatus 3 and the primary stick collecting apparatus 5 so as to cause tiers to be discharged from the auxiliary breakdown apparatus 30 onto the landing transfer chains 4, thus providing a continuous flow of lumber 28 to a downstream process.
As best seen in FIG. 1 and FIG. 7 a third preferred etrtbodiment of a conflnuous operaflng longitudinal breakdown apparatus for lumber stacks, the apparatus of the present invention includes an infeed rollcase 1, a support frame 2, a primary breakdown apparatus 3, a stick ~Ilecting apparatus 5, a secondary breakdown apparatus 3a (not as shown in FIG. 1), and a set of landing transfer chains 4. During the lime from the discharge of the last tier 27 from the primary breakdown apparatus 3, until the first tier of a next lumber stack is discharged from the primary breakdown apparatus 3, the secondary breakdown apparatus 3a is activated in a similar sequence of operations as previously described in the description for the first preferred embodiment for the primary breakdown apparatus 3 and the stick collecting apparatus 5 so as to cause flare to be discharged from the auxiliary breakdown apparatus 3a onto the landing transfer chains 4, thus providing a continuous flow of lumber 28 to a downstream process.
As bit seen in FIG. 1 and FIG. 8 a fourth preferred embodiment of a continuous operating longitudinal breakdown apparatus for lumber stacks, the apparatus of the present invenflon includes an infeed rollcase 1, a support frame 2, a primary breakdown apparatus 3, a primary stick collecting apparatus 5, infeed chain transfer 33 {not shown in FIG. 1), an auxiliary tilt hoist 34 (not shown in FIG. 1), a set of spill transfer chains 35 (not shown in FIG. 1), and auxiliary stick collecting apparatus 36 (not shown in FIG. 1). During the time from the discharge of the last tier 27 from the primary breakdown apparatus 3, until the first tier of a next lumber stack is discharged from the primary breakdovm apparatus 3, the auxiliary tilt hoist 34 and the auxiliary stick collecting apparatus 36 are activated in a similar sequence of operaflons as previously described for the primary breakdown apparatus 3 and the primary stick collecting apparatus 5 so as to cause tiers to be discharged from the auxiliary lift hoist 34 onto the spilt transfer chains 35, thus providing a continuous flow of lumber 28 to a downstream process.
As best seen in FIG. 1 and FIG. 9 a fifth preferred embodiment of a continuous operating longitudinal breakdown apparatus for lumber stacks, the apparatus of the present invention includes an infeed rollcase 1, a support frame 2, a tier rake-off apparatus 3b, a primary hoist 3c, a stick collecting apparatus 5, an auxiliary breakdown hoist with retrac~bie knees 37, and a set of landing transfer chains 4. The primary hoist 3c with non-retracting knees 12 descends to a lowest posfion so the tops of the knees 12 are lower than the tops of the infeed rolls 1. A lun~er stack 9 is moved into Loading position over the primary hoist knees 12 and the primary hoist 3c raises the lumber stack 9 to a discharge position. Tiers are discharged until enough of the lumber stack 9a has been discharged so that the primary hoist 3c has reached a hand-off elevation at which an auxiliary hoist 38 with nstractable knees 39 in its lowest posfion is able to extend the retra~ble knees 39 below the par5al lurr~ber stack 9a and the auxiliary hoist 37 continues to raise the partial liner static 9a as the final tiers are discharged. While the auxiliary hoist with retractable knees 37 is raising the partial turner stack 9a, the primary hoist 3c returns to its lowest position and a new lumber stack 9 is translated into the loading position over the primary hoist knees 12. When the last tier of lumber has been discharged from the auxiliary hoist knees 39, the auxiliary hoist knees 39 retract and the primary hoist 3c immediately raises the new lumber stack 9 to an elevation to discharge the first tier from the new lumber static 9, tt~us providing a continuous flow of lumber 28 to a doWmstream process.
As best seen in FIG. 10, tier rake-off assemblies 41a, 41b, and 41c are shown in three states of operation. Tier rake-of!' assembly 41 a is in the position to propel an uppermost tier 13 in the discharge direction and to engage stickers 14 with the sticker sweep arms 22. Tier rake-off assembly 41 b is in the position of resting on the top of uppemwst tier 13 with the weight of the tier rake--off assembly home by the sticker sweep fingers 22. Tier ~.~. &- . I i rake off guides 42, slidably mounted to the rake-off lugs 43, are attached to tier rake-off device 15 and are shown in an elevated position with respect to tier rake-off lug 43. Thus the tier rake-off assembly 41 b is able to rest harmlessly on top of uppem~ost tier 13. Tier rake-off assembly 41c is shown in the position of turning around the drive chain sprockets 44. Leading link 45 is pivotally attached to the top part of tier rake-off lug 43. Trailing link 48 is pivotally attached to an articulating link 47 which is pivotally attached to the bottom part of tier rake-off lug 43. The result of this mounting geometry is to cause the tier rake-off lug 43 and tier rake-off device 15 and the s5cker sweep fingers 22 to rotate in a counter clockwise direction as the tier rake-off assembly 41c begins to rotate in a clockwise direction around drive sprockets 44, thus providing the desired gentle dis-engagement of tier rake-off device 15 from uppem~ost tier 13, and further preventing the sticker sweep frngers from rotating in an interference path with uppermost tier 13.
As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modficatrons are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.
Claims (19)
1. A breakdown apparatus for unstacking individual tiers of a lumber stack comprising:
(a) a hoist for vertically raising said lumber stack incrementally, one tier at a time.
(b) a rake-off device which engages one end of the uppermost tier on said lumber stack and propels said tier toward a discharge end, in a direction parallel with the longitudinal axis of the lumber on said lumber stack.
(c) a retaining device located at said discharge end to prevent the second from uppermost tier from moving when said rake-off device propels said uppermost tier in said longitudinal direction toward said discharge end.
(d) a support frame for said hoist and said rake-off device.
(a) a hoist for vertically raising said lumber stack incrementally, one tier at a time.
(b) a rake-off device which engages one end of the uppermost tier on said lumber stack and propels said tier toward a discharge end, in a direction parallel with the longitudinal axis of the lumber on said lumber stack.
(c) a retaining device located at said discharge end to prevent the second from uppermost tier from moving when said rake-off device propels said uppermost tier in said longitudinal direction toward said discharge end.
(d) a support frame for said hoist and said rake-off device.
2. The device of claim 1 wherein said rake-off device includes a stick rake-off device for engaging the stickers which separate said uppermost tier from the remainder of said lumber stack and wherein said stick rake-off device propels said stickers toward said discharge end of said lumber stack.
3. The device of claim 2 wherein said stick rake-off device is attached to said rake-off device.
4. The device of claim 2 wherein a sticker collection means is placed at said discharge end of said lumber stack so as to collect said stickers as they fall by gravity from said discharge end of said lumber stack.
5. The device of claim 4 wherein said stickers are translated from a location in said lumber stack to a stick storage bunk without changing the horizontal direction of translation and without changing the orientation of the longitudinal axis of said sticks
6. The device of claim 1 wherein a powered roller is located at said discharge end so as to engage the underside of said uppermost tier some time after said uppermost tier has begun to move by the urging of said rake-off device.
7. The device of claim 6 wherein said powered roller comprises a plurality of powered rollers wherein one or more of said plurality of powered rollers engages the top side of said uppermost tier.
8. The device of claim 7 wherein some of said powered rollers comprise non-powered rollers.
9. The device of claims 7 and 8 wherein a scraping device is located on the infeed side of a roll on the top side of said uppermost tier so as to hold back sticks and debris which may be on the top side of said uppermost tier and to prevent said sticks and debris from reaching said roll, and wherein said scraping device is located approximately above said stick collection means of Claim 4 such that said sticks and debris will fall by gravity and may be guided into said stick collection means.
10. The device of claim 1 wherein a plurality of said breakdown apparatuses are arranged so as to alternately feed tiers of lumber to a common production line in a continuous manner such that while one of said breakdown apparatuses is occupied with the process of loading a new package of stacked lumber, another of said breakdown apparatuses can continue to feed tiers of lumber to said common production line.
11. The device of claim 1 wherein a secondary hoisting device with retractable arms is arranged such that said retractable arms extend and engage the underside of a partly discharged lumber stack and act on said partly discharged lumber stack in the same manner as said breakdown apparatus, and wherein said secondary hoisting device can continue to incrementally raise said partly discharged lumber stack until the last tier of said partly discharged lumber stack has been discharged, while said breakdown apparatus is in the process of loading a new lumber stack.
12. The device of claim 1 wherein said hoist comprises a primary breakdown hoist wherein the lifting arms on said primary breakdown hoist are retractable and wherein said lifting amp are arranged such that said lifting arms extend and engage the underside of said lumber stack and said primary breakdown hoist can continue to incrementally raise said lumber stack until the last tier of said partly discharged lumber stack has been discharged.
13. The device of claim 12 wherein a secondary hoisting device with retractable lifting amps is arranged such that said retractable lifting arms extend and engage the underside of a new lumber stack after said primary breakdown hoist has failed said lumber stack high enough to clear said new lumber stack and after said new lumber stack has been brought into hoisting position and wherein said secondary hoisting device can continue to incrementally raise said new lumber stack until said test tier of said new lumber stack has been discharged.
14. The device of claim 1 wherein said breakdown apparatus is arranged in conjunction with a tilt breakdown hoist so as to alternately feed tiers of lumber to a common production line in a continuous manner such that while said breakdown hoist is in the process of loading a new lumber stack, said tilt breakdown hoist can continue to feed tiers of lumber to said common production line, and while said tilt breakdown hoist is in the process of loading a new lumber stack, said breakdown hoist can continue to feed tiers of lumber to said common production line.
15. The device of claim 1 wherein said rake-off device comprises a rake-off bar shaped so as to extend across the full width of said uppermost tier and to engage the ends of lumber on said uppermost tier without extending down so far as to engage a lower tier.
16. The device of Claim 15 further comprising a plurality of rake-off bars mounted on a driven conveyor means such that said rake-off bars re-circulate continuously in the direction of discharge wherein said rake-off bars alternately engage successive tiers of lumber.
17. The device of Claim 16 wherein said plurality of rake-off bars are attached to said driven conveyor means by an articulating linkage so as to cause said rake-off bars to be relieved from their engagement with the ends of said lumber on said uppermost tier at the point when said articulating linkage begins to travel around the sprockets of said driven conveyor means and at a point where said rake-off bars are no longer required to urge said uppermost tier in said discharge direction.
18. The device of Claim 16 wherein said plurality of rake-off bars are attached to said driven conveyor means by a collapsible linkage so as to allow said rake-off bars to ride harmlessly on the top surface of said uppermost tier if said rake-off bars do not engage said ends of said lumber on said uppermost tier, and so as to allow said rake-off bars to be attached to said driven conveyor means at a spaced apart distance less than the length of said uppermost tier.
19
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2388853 CA2388853A1 (en) | 2002-06-17 | 2002-06-17 | Longitudinal breakdown apparatus for lumber stacks |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2388853 CA2388853A1 (en) | 2002-06-17 | 2002-06-17 | Longitudinal breakdown apparatus for lumber stacks |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2388853A1 true CA2388853A1 (en) | 2003-12-17 |
Family
ID=30005491
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2388853 Abandoned CA2388853A1 (en) | 2002-06-17 | 2002-06-17 | Longitudinal breakdown apparatus for lumber stacks |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2388853A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106697822A (en) * | 2016-12-27 | 2017-05-24 | 郑飞 | novel plate sticking preventing device |
| CN108705608A (en) * | 2018-05-29 | 2018-10-26 | 景宁畲族自治县畲山凤民族工艺品开发有限公司 | Full-automatic wood cutting equipment |
| CN112607438A (en) * | 2020-12-11 | 2021-04-06 | 上海爱仕达机器人有限公司 | Feeding machine |
| SE2250817A1 (en) * | 2022-06-30 | 2023-12-31 | C Gunnarssons Verkst Ab | A gripping device for the wood industry |
-
2002
- 2002-06-17 CA CA 2388853 patent/CA2388853A1/en not_active Abandoned
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106697822A (en) * | 2016-12-27 | 2017-05-24 | 郑飞 | novel plate sticking preventing device |
| CN108705608A (en) * | 2018-05-29 | 2018-10-26 | 景宁畲族自治县畲山凤民族工艺品开发有限公司 | Full-automatic wood cutting equipment |
| CN112607438A (en) * | 2020-12-11 | 2021-04-06 | 上海爱仕达机器人有限公司 | Feeding machine |
| SE2250817A1 (en) * | 2022-06-30 | 2023-12-31 | C Gunnarssons Verkst Ab | A gripping device for the wood industry |
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