US3780611A

US3780611A - Sawmill

Info

Publication number: US3780611A
Application number: US00171116A
Authority: US
Inventors: J Beckman
Original assignee: CALUMET HARBOR LUMBER CO
Current assignee: CALUMET HARBOR LUMBER CO
Priority date: 1971-08-12
Filing date: 1971-08-12
Publication date: 1973-12-25
Anticipated expiration: 1990-12-25

Abstract

A sawmill, including a log bed for feeding a log, saw means for cutting the log, and a cut-timber bed which receives the timbers into which the log is cut, is inclined to one side so that the log and cut timbers are held in place by their own weight. The sawmill has two gangs of blades which are arranged perpendicularly to each other so that a log can be cut in a single operation directly into timbers. The two gangs of blades are metal cutting blades so that the sawmill can be used to cut logs containing foreign objects, such as nails.

Description

United States Patent Beckman Dec. 25, 1973 SAWMILL 2,609,048 9 1952 Samans et al 143/8] 616,220 12/1898 Wilkin 143/81 [76] lnvemor- Jem Wllso Beckman c/o 2,684,088 7/1954 Miller 83/436 Calumet Harbor Lumber Co., 13 51 s B ff l Ave. Chicago, {IL FOREIGN PATENTS OR APPLICATIONS 60633 321,045 4/1922 Germany 143/60 R [22] filed: 1971 Primary ExaminerDonald R. Schran [21] Appl. No.: 171,116 Attorney-George N. Hibben et a1.

52 US. (:1 83/751, 83/760, 83/4253, 1571 ABSTRACT 83/431 A sawmill, including a log bed for feeding a log, saw [51] Int. Cl B27b 3/04, B27b 3/22 means for cutting the log, and a cut-timber bed which [58] Field of Search 143/68 R, 68 A, 60 R, receives the timbers into which the log is cut, is in- 143/60 A, 60 B, 63 A, 68 A, 69, 75, 81, 82, clined to one side so that the log and cut timbers are 83, 84 R, 84 C, 84 A, 1 R, 38 A; 83/436, held in place by their own weight. The sawmill has two 751, 781, 404.1, 675, 778, 760, 431, 425; gangs of blades which are arranged perpendicularly to 144/.3 P each other so that a log can be cut in a single operation directly into timbers. The two gangs of blades are [56] References Cited metal cutting blades so that the sawmill can be used to UNITED STATES PATENTS cut logs containing foreign objects, such as nails. 2,654,404 10/1953 Neuhauser et a1. 143/84 R X 10 Claims, 9 Drawing Figures PATENTEB UECZ 5 I915 SHEENHIFS SAWMILL Lumber saws presently available cut rapidly through wood but are damaged or ruined should the saw blade strike a metal nail, hook, or other foreign object in the log. Such foreign objects are found in logs taken from developed areas such as farms or cities. Prior lumber saws, even if fitted with metal cutting blades, cannot be economically used to cut logs containing such foreign objects since the metal cutting blades cut at slow speed.

Prior lumber saws usually have a flat horizontally extending log bed which supports the log while it is being fed into cutting blades of the saw. A log clamping mechanism provided on the log bed holds the log in place to prevent the log from shifting or rolling during sawing. Operation of the clamping mechanism requires the attention of a saw operator, and the time required for clamping the log in place further reduces the productivity of the saw. The clamping mechanism also increases the cost and the complexity of the saw.

Further, in prior saws, after being clamped, the log is then fed into a gang of parallel saw blades which extend vertically from the horizontal log bed. As the log is fed into the saw blades, it is cut into wide planks. Since the gang of saw blades extends vertically, the wide side of the planks also extend vertically, and the planks are unstable and tend to fall over. The result is that additional handling operations must be performed by the saw operator in order to clear the cut planks from the rear of the saw.

Such planks usually are not suitable for use directly and are recut into smaller sizes, such as 4 inches X 4 inches timbers, depending upon their ultimate use. In prior saws, the planks are removed from the back 'end of the saw, are returned to the front end or log bed so that the wide side thereof is horizontal, and then are passed through the blades again to be cut into timbers. All these operations require additional time and attention from the saw operator and reduce the productivity of the saw.

If several of the planks are stacked on top of each other and cut together, the timbers cut from the several planks are even more unstable and have a greater tendency to become unstacked than the planks themselves. Again, additional handling by the saw operator is necessary to restack the timbers after being cut.

The sawmill of the present invention has metal cutting blades for cutting logs which may contain foreign objects such as nails, hooks, etc. The saw of the present invention also has a log bed adapted to hold and feed a log and has cutting or saw means which extend transversely from the log bed for cutting the logs. Both the log bed and saw means are inclined from horizontal or tipped to one side, so that the log may be held on the log bed without clamping. The log bed has means which are adapted to support the log, and the log is held in place against the support means by its own weight. This construction results in a less costly to manufacture and a more productive saw since the heretofore required clamping mechanism and clamping operation have been eliminated.

The saw of the present invention has cutting means comprising, preferably, two gangs of parallel saw blades, one gang being perpendicular to the other so that a log may be cut directly into timbers on only one pass through the saw making it possible to economically cut logs containing foreign objects.

The sawmill of the present invention includes a cuttimber bed which is also inclined from horizontal so that timbers cut from logs of varying sizes are held neatly stacked on the cut-timber bed by their own weight.

The saw of the present invention has an additional advantage in that the blades of the saw have both a reciprocating cutting motion in a direction transverse to the log and an oscillating motion in a direction parallel to the lOg. The oscillating motion prevents a log which is continously fed into the saw blades on both the cutting and return stroke from becoming jammed against the blade on the return stroke.

An additional advantage is provided by driving the two gangs of blades out-of-phase so that some of the blades are cutting while other of the blades are on a return stroke, thus reducing the stresses imposed on the saw and also permitting the use of a smaller size motor to power the saw.

The saw of the present invention further includes means to discontinue the oscillating motion of one gang of blades after it has finished cutting through the log, thus preventing the possibility of jamming the log into the other gang of blades which has not finished cutting through the log.

The objects and other advantages of the saw of the present invention will become apparent from the subsequent detailed description taken in conjunction with the accompanying figures of the drawings wherein:

FIG. 1 is a rear elevational view of a saw embodying the present invention;

FIG. 2 is a side elevational view of the saw shown in FIG. 1;

FIG. 3 is a fragmentary front elevational view taken on the line 33 of FIG. 2;

FIG. 4 is a sectional view taken on the line 4-4 of FIG. 1; I

FIG. 5 is an enlarged fragmentary sectional view taken on the line 5-5 of FIG. 2;

FIG. 6 is a fragmentary sectional view taken on the line 66 of FIG. 5, showing the saw in one position;

FIG. 7 is a fragmentary sectional view similar to FIG. 6, but showing the saw in another position;

FIG. 8 is a sectional view taken on the line 88 of FIG. 6; and

FIG. 9 is a fragmentary perspective view of the rear portion of the saw, showing a log and cut timbers in dashed lines.

A general overall view of the saw of the present invention is shown in FIGS. 1 and 2. The saw comprises a log bed, indicated generally at 10, which is longitudinally horizontal, but is laterally inclined to one-side. The log bed is at the front of the saw and is adapted to carry a horizontal log 16, and means for sawing the logs which, in this instance, includes first saw means indicated generally at 12, and second saw means indicated generally at 14. The first and second saw means 12 and 14 are mounted on a frame, indicated generally at 15, which extends above the log bed 10. The saw means 12 and 14 are relatively movable with respect to the log 16, and the saw means 12 and 14 include blades for cutting the log 16. The saw means 12 and 14 are mounted transverse to each other, and are driven by power drive means indicated generally at 18. At the rear of the saw is a cut-timber bed 20 which is adapted to receive the timbers 21 into which the log 16 is cut. The log bed 10, the saw means 12 and 14, the frame 15,

the power drive means 18, and the cut-timber bed are laterally inclined with respect to horizontal or tipped towardone side, for purposes which will hereinafter become apparent, and are mounted on a base 22.

The base 22 comprises two sets of spaced-apart

support members

24 and 26 which carry cross members 28. The

support members

24 and 26 are arranged in two longitudinal rows. As can be seen in FIG. 1, when viewed from the rear of the saw, the row of support members 24, at the left, is considerably shorter than the row of support members 26. In this instance, the lower ends of both

support members

24 and 26 are set upon the ground to support the saw. The support members 24 are shown as vertical, while the support members 26 are inclined approximately 15 from vertical. Several cross members 28 are secured to the upper ends of the

support members

24 and 26,-and the cross members are also inclined with respect to the ground at about an angle of 15. Other angles in a range of from a few degrees to more than 30 could also have been used.

The log bed 10 is adapted to hold the log 16 for sawing and comprises a bottom support or wall 29 and a side support or wall 31 which extends, preferably, perpendicularly from the low edge of the bottom wall. The bottom wall 29 is adjustably secured to the upper surfaces of several of the cross members 28, and the side wall 31 is adjustably secured to portions of the base 22. The

walls

29 and 31 are inclined with respect to horizontal ground and are adapted to hold the log 16 in place for sawing without the use of clamps. The log 16 will not shift or roll on the inclined log bed 10 since it is held against the

inclined walls

29 and 31 by its own weight. The log 16 can be easily placed on the log bed 10, such as by a fork lift truck.

' The log bed 10 also includes means for feeding the log 16 into the saw means 12 and 14 at an appropriate speed. In this instance, the feeding means comprises a pusher block 33 (FIG. 2) which is slidably mounted on the log bed 10, a pair of threaded feed screws 35 and 37 which engage the block 33, and driving means 39 for rotating the screws '35 and 37 in a forward or a reverse direction. The pusher block assembly 33 has a face 40 made of wood which is adapted to engage the end of the log 16. As indicated by the dashed lines 41 in FIGS. 2 and 3, a series of saw cuts made by the blades of the first saw means 12 extend from the face 40 into the block 33 to permit the block 33 to push the log 16 through the first saw means 12.

The feed screws 35 and 37 extend the length of the log bed 10 and are rotatably mounted on the log bed. The feed screws 35 and 37 engage threaded portions 42 (FIG. 2) of the block 33 so that as the screws rotate in the block, the block will move toward the saw means 12 and 14 or away from the saw means 12 and 14 depending upon the direction of rotation of the screws. Sprockets 43 and 44 (FIG. 3) are secured to the front end of the feed screws 35 and 37 and are connected by a continuous chain 45 which also engages an idle sprocket 47 and a sprocket 49 mounted on a jackshaft 51 secured to portions of the log bed 10. The use of a single continuous chain to drive both

screws

35 and 37 from the jackshaft 51 eliminates the possibility of damaging the screws or the pusher block, which could occur if separate chains had been used, and if one of the screws continued to rotate after one of the chains breaks.

While other means could be used to reverse the direction of rotation of the feed screws 35 and 3 7, in this instance a reversible motor 52 is used. The motor 52 rotates in one direction to feed the log into the saw means 12 and 14 and rotates in the opposite direction to return the pusher block 33 to its starting position shown in FIG. 2. The jack-shaft 51 is driven by the reversible motor 52 through a gear reduction unit 53 (FIGS. 3 and 4). The motor 52 and the gear reduction unit 53 are mounted on the log bed 16. The motor 52 drives a belt 54 and an input pulley 55 which is mounted on the gear reduction unit 53. The gear reduction unit 53 has two output shafts which rotate at different speeds but rotate in the same direction and on which are mounted output sprockets S7 and 58. Each of the

output sprockets

57 and 58 is connected by its

own chain

59 and 60 to

sprockets

61 and 62 of a clutch mechanism 63 (FIG. 4) mounted on the jackshaft 51. The clutch mechanism 63 can be positioned so that only the sprocket 61 drives the jackshaft 51 or so that only the sprocket 62 drives the jackshaft. The gear reduction unit 53 and the

sprockets

57, 58, 61 and 62 are sized to move the pusher block 33 toward the saw means 12 at an appropriate cutting speed and to quickly return the pusher block 33 after completion of the sawing operation. The motor 52 driving the feed screws 35 and 37 can be either manually switched into reverse or the reversing operation can be carried out automatically by a conventional arrangement of limit switches which control the operation of the motor 52 and clutch mechanism 63.

The frame 15 on which the first and second saw means 12 and 14 are mounted, comprises a pair of channel members 64 on the low side of the saw and a single channel member 65 on the high or opposite side, the

channel members

64 and 65 being tied together by several cross members, such as the member 66. The

channel members

64 and 65 are inclined from vertical, and the cross members are inclined from horizontal. To help hold the frame 15 in its inclined position, a brace 68 is provided and extends between the upper portions of the channels 64 and the ground.

A log hold-down device 69 (FIG. 2) prevents the log 16 from moving or shifting due to sawing motions. The hold-down device 69 comprises a heavy steel plate having a curved forward edge 70 on which are formed a plurality of teeth for engaging the top or upper surface of the log. The hold-down device 69 is pivotally mounted on a pin 71 of a bracket 72 which is secured to the frame 15 above the log bed 10. The log holddown device 69 swings to automatically compensate for various sizes of logs being cut, no adjustment by the saw operator being necessary.

The saw includes first saw means 12 to make a first set of cuts in the log 16, which are inclined from vertical, and second saw means 14 to make a second set of cuts in the log, which are transverse to the first set of cuts and, in this instance, perpendicular thereto and inclined from the horizontal. This arrangement of the saw means 12 and 14 has the advantage of permitting the log 16 to be directly cut into timbers. The arrangement has the further advantage of permitting easy discharge of the sawdust resulting from the second cuts into the first cuts which being inclined from the vertical are therefore more easily emptied by the downward movement of the saw blades.

While other saw arrangements can be used, in this instance, both first saw means 12 and second saw means 14 comprise sash saws, each having a plurality or gang of blades mounted thereto. The saw of the present invention may be used to cut logs containing foreign objects, such as tramp iron, nails, hooks, metal scrap, etc., to this end metal and wood cutting linear saw blades are installed in the sashes.

The first saw means 12 comprises a generally rectangular sash frame 73 (FIG. 5) having four

sides

75, 76, 77 and 78. The upper side 75 is made from one small channel 83 (FIG. 6) and a larger channel 85, and the lower side 76 is made of a pair of small channels 87. Each of the two remaining

sides

77 and 78 of the sash 73 are made of single channels. The

channels

77 and 78 extend upwardly above the upper side 75 and extend below the lower side 76 as shown in FIG. 5. A gang of vertically inclined saw blades 88 is mounted between the upper and

lower sides

75 and 76 of the sash 73. While any number of blades may be used, in this instance five blades 88 are shown and are spaced equal distances apart. Each of the blades 88 is held at its upper and lower ends by a blade hanger 91. The hanger 91 has a bifurcated end 93 adapted to receive and hold an end of the blade 88 and a threaded end 95 which extends between the

channels

83 and 85 of the upper side 75 and the channels 87 of the lower side 76 of the sash 73. A washer block 96 and nut 97 retain each of the hangers 91 in place on the sash 73 and, also, permit adjustment of the tension of the blades 88. The spacing between the blades 88 may be varied by sliding the blades and their associated hangers 91 along the

channels

83 and 87, and the blades may be removed or added to the sash as desired. Preferably, the blades 88 are arranged to execute a cutting stroke in a downward direction, and thus, the weight of the sash 73 is utilized to help cut the log.

Guides 100, guide blocks 101 and guide blocks 102 guide the saw sash 73 and are shown in FIGS. 6, 7, and 8. Each guide 100 comprises a vertically inclined oiled oak plank which is secured to the insides of one of the channels 64 and the channel 65. The

sides

77 or 78 of the sash 73 engage the guides 100. Two pair of guide blocks 101 are secured to the upper ends of the guides 100, and two pair of guide blocks 102 are secured to the lower ends of the guides 100. Two pair of guide blocks 101 are spaced closely adjacent the front and rear of the

sides

77 and 78 of the sash 73, and the two pair of guide blocks 102 are spaced adjacent the front and rear of the

sides

77 and 78 of the sash 73 but are spaced further apart than the guide blocks 101. In addition, further guide means in the form of a plurality of

plank members

108 and 109 are provided for the lower end of the sash. The

plank members

108 and 109 hang or depend rigidly from the lower side 76 of the sash 73. Each of the

plank members

108 and 109 is joined at its upper end to the channels 87 and at its lower end to a channel 110 which at its ends engages the

sides

77 and 78. A shaft, hereinafter more fully described, which is mounted on the frame 15, extends between the

plank members

108 and 109 to loosely guide the lower end of the sash 73. As is apparent from FIGS. 6 and 7, the upper side 75 of the sash 73 is capable of only slight movement in a left-to-right direction, while the lower side 76 of the sash 73 is generally capable of greater movement in the same direction, as hereinafter described. The saw sash 73 is also movable in a generally vertically inclined direction, as will hereinafter be described. The sash guide blocks 101 and 102 are of sufficient size to accommodate such vertically inclined movement without the sash 73 leaving the guide blocks 101 and 102.

As is shown in FIGS. 1 and 4, means 18 for driving the saw sash 73 is provided and includes a motor 111 mounted on the frame 15. The motor 111 drives belts 112 which drive a pulley 114 mounted on a shaft 115, the shaft 115 being rotatably mounted on the frame 15. The shaft 115 carries a flywheel 116 thereon and a sprocket 118, and sprocket 118 in turn drives a chain 117 which rotates a sprocket 119 on a crankshaft 120. The crankshaft 120 has a crankpin 121 and is mounted in bearings 122 (FIG. 1) secured to the frame 15. A crankrod 123 is connected to the crankpin 121 of the crankshaft 120 and is pivotally connected at its lower end to a block 124 secured to the large channel 85 of the sash 73. Thus, as the crankshaft 120 rotates the sash 73 reciprocates or moves down and up about 6 inches in a cutting stroke and a return stroke, as will hereinafter be further described.

The saw means 12 and 14 not only reciprocate transversely to the log 16 for cutting and return strokes but also oscillate toward and away from the log. This construction has the advantage of bringing the blades into contact with the log on the cutting stroke and withdrawing the blades from contact with the log on the return stroke.

While the entire sash 73 could be made to oscillate in a right and left direction as shown in FIGS. 6 and 7, in this instance only the lower side 76 oscillates. The magnitude of oscillation of the sash is less than its reciprocating motion and is about 1 inch. A camshaft 126, the shaft heretofore mentioned, extends through the

plank members

108 and 109 on the sash 73, as shown in FIGS. 5, 6 and 7 to oscillate the sash. The camshaft 126 comprises a circular rod which extends across and is rotatably mounted on bearings secured to the frame 15. The camshaft 126 has a similar circular portion of rod 128 eccentrically secured thereto, as by welding. The

plank members

108 and 109 are spaced apart as shown in FIG. 6, to permit the camshaft 126 to rotate there-between. As the camshaft 126 rotates, the eccentric rod 128 contacts the rightmost plank members 109, and the lower side 77 of the saw sash 73 is positioned toward the log 16, as shown in FIG. 6. As the camshaft 126 rotates further, the eccentric rod 128 contacts the leftmost plank members 108, and the lower side 77 of the saw sash 73 is then positioned away from the log, as shown in FIG. 7. The camshaft 126 is timed in relationship to the crankshaft 120 so that the blades 88 and the teeth thereon are brought into contact with the log 16 on the cutting stroke and are removed from contact with the log on the return stroke. It should be understood that mechanisms other than the one described can be used to make the blades oscillate on the cutting and return strokes.

The camshaft 126 is indirectly driven by crankshaft 120. To this end of the crankshaft 120 drives a sprocket 129 (FIG. 4) mounted thereon and a timing chain 131. The timing chain 131 engages

idle sprockets

132, 134, and 136 and

other sprockets

138, 140 and 142, hereinafter more fully described. The timing chain 131 engages a lower sprocket 144 mounted on a lower shaft 145 which in turn drives the camshaft 126 through clutch means 147, hereinafter more fully described.

The saw includes the second saw means 14 comprising a second saw sash 150 preferably movable in a direction perpendicular to the first saw sash 73. The second saw sash 150 is constructed similar to the first saw sash 73 and has an upper side 151 (FIG. a lower side 152, and two remaining

sides

153 and 155 to which a second set of blades 157 are secured by similar hangers 91. The second set of blades 157 are preferably perpendicular to the first set of blades 88 so that the log 16 when passed through the saw is cut directly into rectangular or square timbers 21 depending upon the blade spacing;

The second saw sash 150 has a motion similar to the first saw sash 73, i.e., it generally reciprocates from one side-of the saw to the other side of the saw for a cutting and return stroke and oscillates toward the log bed on the cutting stroke and away from the log bed on the return stroke. The magnitude of the reciprocation and oscillation of the second saw sash 150 is similar to that for the first saw sash 73. However, the cutting stroke of the second saw sash 150'is out of phase, preferably 180, with the cutting stroke of the first saw sash 73 so that the forces and stresses imposed on the parts of the saw are reduced.

As shown in FIG. 5, the second saw sash 150 is driven by the lower end of the crankrod 123 which also drives the first saw sash 73. The reciprocating motion of the lower end of the crankrod 123 and the first saw sash 73 in a plane inclined from vertical is converted to reciprocating motion of the second saw sash 150 in a plane perpendicular to the first mentioned plane. As shown in FIG. 5, to accomplish such change of direction the

sashes

73 and 150 are joined by linkage means 159. In this instance, linkage means 159 comprises two

roller chains

163 and 165 which are connected to the

sashes

73 and 150. The ends 160 and 161 of the

chains

163 and 165 are secured in a chain holding assembly 167 which is secured to the large channel 85 of the sash 73. As the sash 73 reciprocates the chain ends 160 and 161 move with that sash. The chain 163 passes under the idler sprocket 169 secured to a cross member 171 (FIGS. 5, 6 and 7) of the frame and has its other end 173 secured to the second saw sash 150. The other chain 165 passes over an upper idler sprocket 175 and under'a lower idler sprocket 177, both

sprockets

175 and 177 also being secured to the frame 15. The other end 179 of the latter chain 165 is also secured to the second saw sash 150. The second saw sash 150 is guided to be movable in a direction generally perpendicular to the movement of the first saw sash 73, as is hereinafter described. When viewed as shown in FIG. 1, the arrangement just described causes the second sash 150 to move toward the right when the first saw sash 73 moves downward and causes the second saw sash 150 to move toward the left when the first saw sash moves upward, thus reciprocating the sash 150.

As was mentioned, the second saw sash 150 is guided for reciprocating motion and, in this instance, is hung from the

channels

64 and 65 of the frame 15 on two

heavy rods

181 and 182. The

rods

181 and 182 have their

upper ends

183 and 185 pivotally secured to the frame and have their lower ends 187 and 188 pivotally secured to diagonally opposite corners of the second saw sash 150. Since the

rods

181 and 182 are of equal length the saw sash 150 moves with a parellelogramtype motion, and because the rods are of considerable length the movement of the sash 150 in the longitudinal direction of the rods is negligible.

The second saw sash 150, also, oscillates toward the log bed 10 on the cutting stroke as is shown in solid lines in FIG. 8 and away from the log bed on the return stroke, as is shown in dashed lines in FIG. 8. In this instance, to oscillate the second saw sash 150, three

eccentric cams

191, 193 and 195 are provided at the left side of the frame 15, as shown in FIG. 1. Each

cam

191, 193 and 195 is rotatably mounted on a cantilevered shaft 197 fixedly secured to the frame 15 and is driven by one of the

sprockets

138, and 142 heretofore mentioned. The

sprockets

138, 140 and 142 are secured to the

cams

191, 193 and 195 and are driven by the timing chain 131, as was heretofore described. The

sprockets

138, 140 and 142 are sized so the

cams

191, 193 and 195 rotate at the same angular speed as the camshaft 126 and crankshaft 120. Due to the wrap of the chain 131 around the

sprockets

138, 140 and 142, the

end cams

191 and 195 rotate in one direction while the center cam 193 rotates in the opposite direction. The

cams

191, 193 and 195 are formed by welding an arcuate segment 201 (FIG. 4) of circular pipe to a full circular pipe section 203. The

cams

191, 193 and 195 are of sufficient axial length to remain in contact with bearing

surfaces

205 and 207 provided on the second saw sash as that sash reciprocates from side to side. As can be seen in FIGS. 4 and 8, the bearing surfaces 205 and 207 are provided by

parallel plank members

209 and 211 rigidly secured to the side of the second saw sash 150. The plank members 209 and 21 l are spaced apart by the members 213 (FIG. 4). The opposite side of the second saw sash is guided by a vertical roller 215 (FIG. 8) which loosely engages the rear surface 216 of the second saw sash, the roller 215 being secured to the frame 15. I

When a log is continuously fed into a reciprocating blade on both the cutting and return stroke it is advantageous to have the blade oscillate toward the log on the cutting stroke and away from the log on the return stroke. However, the oscillating motion of the blades can become a problem when two different gangs of blades are used and one gang of blades has completely cut through the rear end of the log before the other gang of blades. For example, in the present invention, should the first gang of blades 88 cut through the log and for a moment be free of the end of the log, the blades 88 of the first saw sash 73 on their next oscillation in a direction toward the second saw sash 150 will tend to jam the log 16 into the blades 157 of the second saw sash which are executing a cutting stroke and have not yet completely out through the log. Such jamming can result in broken blades or damage to the saw. To prevent such problems, the present invention provides means to halt or disconnect the oscillation of the first gang of blades after they have cut through the log 16.

Means for accomplishing this task preferably comprises clutch means 147 (FIG. 5) having one member 221 mounted on the camshaft 126 and another member 223 mounted on the lower shaft 145. The members 221 and 222 have engageable portions, and when the two

members

221 and 223 of the clutch means contact or engage, the lower shaft 145 can rotate the camshaft 126, but when the

members

221 and 223 are spaced apart or disengaged the lower shaft 145 can no longer rotate the camshaft 126. After the blades 88 have cut through the log 16, the clutch means 147 is disengaged.

A positive type clutch is used since it is desirable to keep the two

sashes

73 and 150 in timed relation.

To cause disengagement of the clutch means 147, as the blades 88 cut through the end of the log 16 a projection 230 (FIG. 4) on the pusher block 33 strikes an arm 233 pivotally mounted on the frame 15, and the arm 233 moves upward. A pin 234 is suspended from the arm by a rod 235 and is slidable in a block 236 secured to one of the supports 24. The pin 234 engages an opening in 237 in a lever arm 238. The lever arm 238 is pivotally mounted on another support 24 and is held in position by the pin 234. As the arm 233 moves upward, the pin 235 is withdrawn from the opening 237 in the lever arm 238. The lower shaft 145 is rotatably carried in a bearing 239 mounted on the lever arm 238. With the pin 234 withdrawn, the lower shaft 145 is free and swings a slight distance away from the camshaft 126 to disengage the

clutch members

221 and 223.

As shown in FIG. 1, the log 16 is adapted to be cut into a plurality of timbers, the shape of which depends on the placement of the blades of the first and second saw means 12 and 14. In this instance both sets of

blades

88 and 157 are set equal distances apart, and generally square timbers 21 are cut. The outer portion, or slabs, of the log is cut into scrap pieces 241 and is not suitable for timbers but may be useful for other purposes.

The cut-timber bed 20 is adapted to separate the timbers 21 from the scrap pieces 24] and holds the cut timbers 21 neatly stacked, by their own weight. The

cut-timber bed 20 includes a bottom splitter or wall 245 (FIG. 9) adjustably mounted on the base 22. The bottom wall 245 may be aligned with the lowest blade 157 of the second saw sash 150. The cut-timber bed 20 further includes two side splitters or

walls

247 and 249 also adjustably mounted on the base 22 and may be aligned with the extreme right-most and left-most blades of the first saw sash 73, as viewed in FIGS. 1 and 8. The

walls

245, 247 and 249 are similarly inclined toward one side as are the

walls

29 and 31 of the log bed 10. The

walls

245, 247 and 249 may be adjusted or shifted to different positions should the abovementioned blades be shifted. The bottom wall 245 terminates closely adjacent the rear of the lowest of the blades 157 of the second saw sash 150, and the

side walls

247 and 249 extend through the blades 157 of the second saw sash to terminate closely adjacent the rear of the blades 88 of the first saw sash 73. The right side wall 249 as shown in FIGS. 1 and 8 has adjustably mounted thereon an additional L shaped splitter or guide 251 which aligns with the next right-most blade 88 and the next lowest blade 157. The L shaped guide 251 helps to keep timbers stacked, particularly when a log ofa smaller diameter than illustrated is cut. Underneath the second saw sash 150 are a plurality of T-shaped cross-over skids 253 (FIG. 1) which extend between the log bed and the cut-timber bed to carry the weight of the log 16 as it makes the transition from the log bed to the cut-timber bed.

As is apparent from the foregoing description an improved saw having first and second saw means for directly cutting logs into timbers has been provided. It is further apparent that the inclined saw means and similarly inclined log bed permits a log to be held in position for cutting by its own weight. A similarly inclined cut-timber bed is provided to hold the cut timbers neatly stacked. It is still further apparent that saw means having an oscillating motion so as to move the blades into contact with the log on a cutting stroke and to withdraw the blades from contact on the return stroke has been provided. It is still further apparent, that means to disconnect the oscillating motion of the saw means which has cut through a log has been provided. It is still further apparent, that the first and second saw means are out of phase so as to minimize the power requirement for the saw and to reduce stresses imposed on the components thereof. It is still further apparent, that when fitted with metal cutting blades the saw of the present invention can be economically used to cut logs containing foreign objects.

While only one embodiment of the saw of the present invention has been herein illustrated and described, it will be understood that modifications and variations thereof may be made without departing from the scope of the invention as set forth in the appended claims.

I claim:

1. A sawmill for cutting a horizontally disposed log containing metal scrap directly into timbers on one pass, comprising first and second gangs of metal and wood cutting linear saw blades mounted in generally vertical planes, said blades of said first gang being disposed generally perpendicularly to said blades of said second gang, said blades of said first gang being generally vertically disposed and cutting the log ahead of said blades of said second gang, and

drive means for driving said first and second gangs of blades in reciprocating motions consisting of cutting and return strokes, said drive means further driving said first and second gangs of blades in oscillating motions and in out-of-phase relation.

2. A sawmill as in claim 1, and further including means for discontinuing the oscillating motion of said first gang of blades after they have cut through the log.

3. A sawmill as in claim 2, and further including cam means for oscillating said first gang of blades, and clutch means, said clutch means being disengagingly connected to said cam means.

4. A sawmill as in claim 2, wherein said first and second gangs of blades are inclined laterally to one side.

5. A sawmill as in claim 4, and further comprising a cut-timber bed behind said blades having a side wall and a bottom wall, both of said walls being laterally inclined to said one side, whereby the timbers into which the log is cut may be held stacked on said cut-timber bed by their own weight.

6. A sawmill as in claim 4, and further comprising a log bed ahead of said blades and having a side wall and a bottom wall, both of said walls being laterally inclined to said one side, whereby the log may be held on said log bed by its own weight.

7. A sawmill as in claim 6, and further comprising a cut-timber bed behind said blades and having a side wall and a bottom wall, both of said walls of said cuttimber bed being laterally inclined to said one side, whereby the timbers into which the log is cut may be held stacked on said cut-timber bed by their own weight.

8. A sawmill as in claim 7, and further comprising cam means for oscillating said first gang of blades, and clutch means, said clutch means being disengageably connected to said cam means so that said cam can be disconnected when said first gang of blades has cut through the log.

9. A sawmill for cutting a horizontally disposed log containing metal scrap directly into timbers on one pass, comprising first and second gangs of metal and wood cutting linear saw blades mounted in generally vertical planes, said blades of said first gang being disposed generally perpendicularly to said blades of said second gang, said first and second gangs of blades being laterally inclined to one side, drive means for driving said first and second gangs of blades in reciprocating motions consisting of cutting and return strokes, said drive means further driving said first and second gangs of blades in oscillating motions, a log bed located in front of said first and second gangs of blades, said log bed having a bottom wall and a side wall, said walls of said log bed being laterally inclined toward said one side to hold the log on said log bed by its own weight, and a cut-timber bed located behind said first and second gangs of blades, said cut-timber bed having a bottom wall and a side wall, said walls of said cut-timber bed being laterally inclined to said one side, whereby said timbers into which the log is cut may be held stacked on said cut-timber bed by their own weight.

10. A sawmill as in claim 9, wherein said first gang of blades is inclined generally l5 from vertical and said second gang of blades is inclined generally 15 from horizontal, said side walls of said log bed and cuttimber beds being inclined generally 15 from vertical, and said bottom walls of said log bed and cut-timber bed being inclined generally 15 from horizontal.

Claims

1. A sawmill for cutting a horizontally disposed log containing metal scrap directly into timbers on one pass, comprising first and second gangs of metal and wood cutting linear saw blades mounted in generally vertical planes, said blades of said first gang being disposed generally perpendicularly to said blades of said second gang, said blades of said first gang being generally vertically disposed and cutting the log ahead of said blades of said second gang, and drive means for driving said first and second gangs of blades in reciprocating motions consisting of cutting and return strokes, said drive means further driving said first and second gangs of blades in oscillating motions and in out-of-phase relation.

7. A sawmill as in claim 6, and further comprising a cut-timber bed behind said blades and having a side wall and a bottom wall, both of said walls of said cut-timber bed being laterally inclined to said one side, whereby the timbers into which the log is cut may be held stacked on said cut-timber bed by their own weight.

10. A sawmill as in claim 9, wherein said first gang of blades is inclined generally 15* from vertical and said second gang of blades is inclined generally 15* from horizontal, said side walls of said log bed and cut-timber beds being inclined generally 15* from vertical, and said bottom walls of said log bed and cut-timber bed being inclined generally 15* from horizontal.