Conveyors: power-driven – Conveyor system for moving a specific load as a separate unit – System includes a rotating or endless carrier with a load...
Reexamination Certificate
1999-05-05
2001-03-13
Ellis, Christopher P. (Department: 3651)
Conveyors: power-driven
Conveyor system for moving a specific load as a separate unit
System includes a rotating or endless carrier with a load...
C198S463500, C198S459500
Reexamination Certificate
active
06199683
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to an apparatus for the singulation or allocation of lumber into lug spaces on a lugged transfer, or other lumber conveying device, and in particular relates to an apparatus capable of collecting, singulating, allocating and consistently spacing, rough sawn lumber or planed finished lumber, or sticks of varying widths, thickness and lengths into consecutive spaced-apart lugs, or allocated spacings onto a transfer, or lugged transfer, or to a stick placing device, at high speeds.
BACKGROUND OF THE INVENTION
Conventional lug loaders or singulators (hereinafter collectively referred to as either lug loaders or singulators) have been found to be inadequate at higher feed speeds. They are also limited in their ability to both singulate and allocate lumber. When lumber is of varying widths and varying in thickness, or bowed, as may be predominant in curve sawing mills, cupped or crooked, it becomes increasingly difficult to handle the lumber at desirable higher speeds.
An example of a conventional lug loader is that taught in U.S. Pat. No. 3,923,142 which issued to Rysti on Dec. 2, 1975. In that patent the means for stopping work pieces prior to being singulated is only briefly mentioned. In particular, what is being taught is singulating boards by use of supporting arms rotating around a closed loop, the orientation of the supporting arms controlled by curved deflectors. Pressing arms in opposed radial pairs, are rotatably mounted above the supporting arms to synchronously clamp a board onto a supporting arm. Downstream flow of the mat of boards is arrested by a stop on each supporting arm. None of the advantages of the synchronized duckers of the present invention are taught or suggested. Rysti also does not disclose a mechanism for allocating or missing a lug space, especially at high speeds. The need to miss lug spaces arises for example where it is desirable to “cut-in-two” a long piece of lumber to meet mill requisites. In a “cut-in-two” situation there is a need to create an empty lug space behind the board. To achieve a “cut-in-two”, a drop saw including a device to lift and set the cut length into the following lug space is provided up-stream on the lugged transfer.
At high speed, deliberately and accurately missing a lug space, which it is an object of the present invention to provide, requires a fast acting method to momentarily deactivate all feed and clamping devices, and subsequently to reactivate those apparatus in the brief time available as the closely spaced lugs are rotated past the singulator.
It is also an object of the present invention to provide for specific board allocating patterns required in the delivering of spacing sticks to a stick placer and its associated stacker to allow placing of sticks on lumber packages possibly having different package lengths.
Applicants are also aware of U.S. Pat. No. 5,518,106, which issued to Allard on May 21, 1996. Allard discloses using fixed pick-up shoes mounted onto rotating discs for engaging and supporting boards being singulated. Fixed shoes however, have the disadvantage that they may mark the underside of the board as the board is translated over the top of the disc and as the board is released. If a board is planned or finished, for example destined for cabinet making or the like, then any marks from the shoe or overhead clamp will reduce the value of the board. Allard also discloses a speed-up belt to pull the board away from the fixed shoes at the top of the disc to prevent the board from being flipped over as the board is released from the shoes. In some mills the boards have been marked for trimming and grading before the lug loader. Thus if the board has been flipped over by the singulator, as may occur in the case of the Allard device, the board must be flipped back by hand to read the mark. This can be difficult in a high speed application.
Many lug loaders in the prior art, particularly those operating at slower feed speeds, require that, in order to stop the delivery of boards to the singulator, the board mat moving downstream into the singulator device must be pushed back upstream by the stopping means, that is, forced away from the fixed pick-up shoe and clamping device. Worse yet, in some prior art devices the board delivery mechanism must be brought to a complete stop. Both pushing the mat of boards back upstream, and stopping the board delivery mechanism, can be impractical at high speed, a problem which is not adequately dealt with in the prior art.
It is therefore an object of the present invention to produce an apparatus wherein the delivery of boards is more controlled, with a simple means for stopping, activating and deactivating both a clamping means and a rotating pickup shoe simultaneously, allowing more precise and faster pick-up and delivery of spaced and allocated boards.
It is further an object of the present invention to produce an apparatus that has a quick acting stopping device for stopping the flow downstream of a board mat adjacent the singulator, wherein the stopping device has an adjustable dwell.
It is yet another object of the present invention to produce an apparatus that reduces the likelihood of leaving marks on the board by the pick-up and clamping device.
It is still another object of the present invention to produce an overhead clamping apparatus that can be retrofitted to existing lug loaders of the general type to improve the speed and consistency of delivery of boards by said existing lug loaders.
SUMMARY OF THE INVENTION
The high speed revolving lug loader of the present invention consists of a board infeed transfer, whereat the boards collect at a plurality of hook stops, so as to abut each other to form a mat of boards. The downstream-most boards in the mat are released by the hook stops and picked up by a plurality of shoes. The shoes are carried in a semi-circular arc on rotating discs. The boards are clamped down onto the shoes by an overhead clamping means. The plurality of shoes are pivotally mounted on the rotating discs. The overhead clamping means are timed to coincide with the timing of the rotation of the shoes on the rotating discs so that a clamp is applied to a board being carried on a shoe. The clamp and shoe interact to pickup and clamp boards so as to deliver the boards individually and sequentially to a lugged transfer, or to allocate boards or sticks to a delivery transfer for a stick placer of the general type.
Each shoe is elongate. One end of each shoe is pivotally mounted to its corresponding rotating disc. The opposite end of each shoe supports a cam follower. The cam follower protrudes from the shoe so as to ride on the cam surface of a cam. The cam is selectively rotatably mounted on a hub shaft, collar or sleeve that may have a common axis of rotation with the axis of rotation of the rotating disc. The cam is selectively rotatable, independently of rotation of the rotating disc. The cam is asymmetric about its axis of rotation so as to provide a cam lobe for actuation of the shoe into engagement with the underside of a board to be singulated when the cam is rotated to elevate the lobe from a non-actuating position to a shoe actuating position.
With the cam in the shoe actuating position, as a shoe is rotated on the rotating disc, the cam follower rides on the cam surface up over the cam lobe thereby forcing the board pickup surface, or, otherwise, the board engaging and supporting surface on the shoe against the underside of the board, urging the board upwardly so as to be carried in a transition arc along an arcuate path defined by the arcuate translation path of the shoe and the arcuate, upwardly exposed, radially outermost edge of the rotating disc. The cam surface smoothly merges from the cam lobe to a radially retracted position relative to the radial extension of the cam lobe, so that in its actuated position the board transitions from being carried by the shoe, to being supported by the radially outermost edge of the rotating disc as the shoe retracts radially inwardly of the radially ou
Johnson Emeric
Michell Steven W.
Newnes William R.
van Varseveld Robert B.
CAE Electronics Ltd.
Dillon, Jr. Joe
Edwards Antony C.
Ellis Christopher P.
LandOfFree
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