US2527024A

US2527024A - Sawmill arrangement

Info

Publication number: US2527024A
Application number: US29761A
Authority: US
Inventors: Walter F Mitchell
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-05-28
Filing date: 1948-05-28
Publication date: 1950-10-24
Anticipated expiration: 1967-10-24

Description

Get, 24 1956 w. F. MITCHELL SAWMILL ARRANGEMENT 2 Sheets-Sheet 2 Filed May 28, 194

nocoooo W M M lfll/ o m M 0 m 6 4 I w t w 7 M 5 W @4 4 4 MM Z v w fiwwnnnumfi X M/ Patented Oct. 24, 1950 UNITED STATES ,PATENT OFFICE Y SAWMILL ARRANGEMENT Walter F. Mitchell, Eugene, Oreg. Application May 28, 1948, Serial No. 29,761

The present invention relates to sawmills and has particular reference to mechanism for facilitating the grading of cants coming from the headrig of a sawmill so as to attain a greater percentage of first-class lumber from the usual run of cants.

The arrangement comprising the present in vention and the apparatus incorporated therein is particularly adapted for the manufacture of lumber from logs that are thirty feet or more in length and several feet in diameter, but the improvements may be incorporated in sawmills designed to operate upon smaller logs if desired. The present invention is particularly useful in the Northwestern regions where Douglas fir and various types of pines reach tremendous sizes.

The principal object of the present invention is to enable a highly skilled grader to mark cants for subsequent trimming to shorter lengths and for subsequent dividing by means of an edger or similar equipment into lumber of suitable dimensions. It is common practice in sawmills to divide a log into cants which may be of any dimensions commensurate with the sizes of the log and the desires of the sawyer, or the orders on hand at the mill. The cants are then fed by means of a conveyor system to various mechanisms, such as an edger, trim saw, or resaw apparatus, to cut the cants into the desired types of lumber. The present invention provides an alternate conveyor system for delivering the selected cants to an edger or to other mechanism including an edger, which alternate conveyor system is under control of an experienced grader. The present invention comprises means whereby the grader may inspect a cant on all sides thereof so as to select and mark on the cant the sizes of lumber which should be cut therefrom to produce the greatest quantity of highest grade pieces. The mechanism may also be coupled with a trim saw by means of which long, tapered cants or cants having other irregularities therein may be cut into shorter lengths if, in the opinion of the grader, a greater recovery could be had from shorter lengths than would be possible by dividing the entire cant endwise into lumber.

The objects and advantages of the present invention will be more readily apparent from inspection of the accompanying drawings wherein the preferred sawmill arrangement and details of the preferred form of cant inspecting device are set forth.

Claims. (Cl. 19833) In the drawings Fig. 1 is a schematic plan Fig. 2'is an enlarged vertical section taken substantially along line 2-2 of Fig. 1; Y N

Fig. 3 is an enlarged detail of the mechanis set forth in Fig. 2 showing a cant in a different position thereon; and

Fig. 4' is a view similar to Fig. 3 showing the apparatus in a different position.

Referring to Fig. 1, a sawmill incorporating the present invention may comprise log handling equipment In by means of which logs are placed upon a reciprocating carriage II. The carriage:

reciprocates past a headrig I2 by means of which the log is sliced into cants which drop from the remainder of the log onto a conveyor system 'in-- cluding a roll frame I3, transfer chains M which move the cants sidewise, and a roller table l5; which delivers the cants lengthwise to an edger l6 by means of which the cant is sliced into the desired sizes of lumber. From the edger the lumber may be transferred to various other trimming or resawing equipment by suitable conveyor equipment.

The present invention comprises the inclusion in the sawmill of an alternative conveyor system fordelivering cants to the edger I6.

I I which maybe selectively brought into play to lift selectedcants sidewise from the roller table: [3 onto chains l8 which transfer the cants to" The marked and graded cants are then fed longi tudinally alonga roller table 2| to a, transverse an inspecting and marking station 20.

Fig. 1 is more fully detailed in Figs. 2, 3 and 4.

In these figures it will be seen that cants Tvhich are delivered transversely by the chains l8 are removed from the ends of the chains l8 by endless chains 30 which are passed about spaced sprockets 3| and 32. The chains 30 are driven by sprockets 33 which are driven by a sprocket 35,-chain 36 and sprocket 31 connected to reduction gearing suitably connected to motive means such as a motor contained in a housing 38. The

chains 30 preferably pass over the sprockets 33 and under laterally spaced, floating,

idler sprockets

39 and 40 whereby the chains may be kept taut at all times even though the upper flight thereof may be raised and lowered, as will presently appear.

Such] a conveyor system includes transfer mechanism] The upper flights of the guided on a vertical guide rod 49 and reciprov cated by a piston 50 extending from a cylinder 5 I. When the piston is extended as seen in Fig. 2 the arms 4| and 42 lie horizontally so that the upper flights of chains 30 extend horizontally.

When the piston 50 is retracted the arms 4| and 42 are raised to the positions illustrated in Fig. 4 to raise the central portion of the chains as illustrated. When the arms are horizontal the chains 30 lie slightly beneath the upper edges of rollers 55 placed at both sides of the several chains and making up the roller table 2|. The rollers 55 are driven by suitable mechanism (not shown) so that when the chains are lowered, as seen in Fig. 3, a cant positioned on the rollers 55 will be moved lengthwise from the inspecting apparatus. If it is desired to return a cant, the direction of movement of chains 30 may be reversed by suitable mechanism (not shown) and the chains elevated to the position shown in Fig. 4 whereby the cant may be lifted from the rollers 55 and fed in either direction by the chains 3|]. It sometimes would be desirable to return an inspected cant to the roller. table I3, in which case the chains |8 could be reversed as well and caused to return the cant to the roller table |3 for delivery to the edger by chains M. The grader may move the cant back and forth several times as desired, and then may finally decide to move the cant onto the rollers 55 for delivery to the edger by means of. the roller table 2| and chains 22. The roller table |5 preferably is provided with suitable transfer mechanism of a similar nature which may be brought into effect to move cants onto the chains 22, which are reversible in movement, and the cants may be returned to the grading station by reversing the direction of rotation of the rollers 55 on roller table 2|. Thus a cant which may have arrived at the roller table |5 may be caught before progressing into the edger and brought back to the grading station over the chains 22 and table 2|. The cant may be returned to the edger by either conveyor system. Suitable controls under control of the grader would be provided adjacent the grading mechamsm.

The grader is stationed adjacent the grading mechanism and stands upon a catwalk 60 along which the controls may be positioned. The catwalk 60 is of sufiicient extent that the grader may walk from one end to another of a cant resting at the grading station. In order to arrest a cant at the grading station a plurality of parallel arms 6| are provided, one adjacent each of the chains 30, the arms extending from a common rockshaft 62 extending beneath the chains 30. The rockshaft 62 may be partially rotated by a lever 63 which is connected to a link 64 pivoted to a crosshead 55 mounted upon a guide rod 66. The crosshead is connected to a piston 61 extending from a cylinder 68 under control of the grader. When the piston is extended the arms 6| lie beneath the level of the chains 30 so that the chains may deliver a cant onto or from the rollers 55. When the piston is retracted, as seen in Fig. 2, a cant on the chains or on the rollers 55 may be lifted and held in elevated position by the arms. In order to hold the bottom edge of a cant tilted by the arms 6| from contacting the chains 30, a short supporting arm 10 is provided adjacent each arm 6|. The arms 10 are loosely mounted on the rockshaft 62 and each arm is connected by a link H to a lever connected to a rockshaft 12. The rockshaft 12 is partially rotated by a lever 13 and a link 14 extending to a piston 15 and cylinder 76. When the piston 15 is extended the supporting arm 10 provides a crotch with the tilting arm 6| to hold the cants above the chains so that the chains may continue to move while the lower side of the cant is inspected by the grader. If the grader desires to have the cant fed onto the rollers 55 he can lower the arms 6| and later lower the supporting arms 10. If, on the other hand, he wishes to mark the cant upon its bottom side, he may wish to turn the cant over, in which case he would raise a plurality of catching arms which are loosely mounted upon the rockshaft 62 and each of which is connected by a link 8| to a lever 82 fastened to a rockshaft 83. The rockshaft 83 may be partially rotated by a lever 84 connected to a link 85 extending to a crosshead and piston arrangement similar to those previously described associated with a vertical cylinder 86. Each catching arm 80 comprises an elongated portion extending in the opposite direction from the tilting arm 6| and a base portion 87 extend ing at an angle thereto to provide a support for the lower corner of a cant held above the chains as seen in Fig. 3. A cant may be tilted onto the arms 80 by lowering the supporting arms 10 and continuing the upward movement of the tilting arms 6| until the cant falls onto the base por-' tions 8'! and the angularly disposed portions of the catching arms 80. The tilting arms 6| may now be lowered, and when the catching arms 50 are lowered the cant will be fed forward by the chains 30 into the reach of the grader. A skilled operator of the present mechanism may turn a cant over several times in a shorter space of time than it takes to' describe the operation of the turning mechanism. In this way a skilled grader may inspect the cant for the most economical subsequent handling thereof.

Having illustrated and described a preferred embodiment of the invention, it should be apparent to those skilled in the art that the invention permits of modification in arrangement and detail. I claim as my invention all such modifications as come within the true spirit and scope of the appended claims.

I claim:

1. A cant inspecting device comprising a feed chain, a first pivoted arm normally lying beneath said chain, means to swing said first arm through a substantial are above said chain whereby a cant fed into position above said first arm by said chain may be tilted sufficiently to inspect the lower side thereof or may be turned over, a second arm normally lying beneath said chain, said second arm being pivoted adjacent said first arm and extending in the opposite direction, means to swing said second arm through a substantial are above said chain whereby a cant tilted by said first arm may be held above said chain in the crotch between said arms, a third arm normally lying beneath said chain, said third arm being pivoted adjacent said first arm and extending in the opposite direction, and means toswing said third arm through a substantial are above said chain whereby a cant being turned over by said first arm may be caught and lowered onto said chain.

2. A cant inspecting device comprising a feed chain, a first ivoted arm normally lying beneath said chain, means to swing said first arm through a substantial are above said chain whereby a cant fed into position above said first arm by said chain may be tilted sufiiciently to inspect the lower side thereof or may be turned over, a second arm normally lying beneath said chain, said second arm being pivoted adjacent said first arm and extending in the opposite direction, means to swing said second arm through a substantial are above said chain whereby a cant tilted by said first arm may be held above said chain in the crotch between said arms, a third arm normally lying beneath said chain, said third arm being pivoted adjacent said first arm and extending in the opposite direction, and means to, swing said third arm through a substantial arc above said chain whereby a cant being turned over by said first arm may be caught and lowered onto said chain, said third arm comprising a short base portion and a long supporting portion disposed at an angle thereto.

3. A cant inspecting device comprising a feed chain, a, pivoted tilting arm normally lying beneath said chain, means to swing said tilting arm through a substantial are above said chain whereby a cant fed into position above said tiling arm by said chain may be tilted suificiently to inspect the lower side thereof or may be turned over, a catching arm normally lying beneath said chain, said catching arm being pivoted adjacent said tilting arm and extending in the opposite direction, means to swing said catching arm through a substantial are above said chain whereby a cant being turned over by said tilting arm ma be caught and lowered onto said chain, said catching arm comprising a short base portion and a long supporting portion disposed at an angle thereto, a short supporting arm normally lying beneath said chain, said supporting arm being pivoted adjacent said tiling arm and extending in the direction of said catching arm, and means to swing said supporting arm through an are above said chain.

4. An inspecting device for variously positioning a board or the like to facilitate inspection thereof, comprising chain means upon which a board may be transported laterally, pivot means lying beneath said chain means, and three arms pivoted on said pivot means and normally underlying said chain means, a first one of said arms normally pointing in one direction under said chain means and the second and third of said arms normally pointing in the opposite direction under said chain means, and means to swing each of said arms independently of the others through a substantial arc above said chain means.

5. An inspecting device capable of turning a board over about its longitudinal edges or of holding the board in various intermediate positions, comprising chain means upon which a board may be transported laterally, pivot means lying beneath said chain means, and three arms pivoted on said pivot means and normally underlying said chain means, two of said arms normally pointing in opposite directions under said chain means, and means to swing each of said arms independently of the others through a substantial are above said chain means, said two oppositely pointing arms being substantially longer than the other one of said three arms.

WALTER F. MITCHELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 591,712 Worth Oct. 12, 1897 771,836 Schantz Oct. 11, 1904 996,386 Williams June 27, 1911 1,246,138 Mitchell Nov. 13, 1917 1,567,153 Kelly Dec. 29, 1925 2,403,673 Mead July 9, 1946 FOREIGN PATENTS Number Country Date 136,472 Germany Nov. 19, 1901