Portable sawmills currently provide a means of safely and securely clamping wooden logs so that the bandsaw blade may cut and process wood parallel to the grain. This type of cut is defined as a rip-cut, and can be used to produce elongate wooden planks or boards. A rip-cut is the fundamental type of cut made by a sawmill.
There exists a desire to cut and process wood perpendicular to the grain of a wooden log on a portable sawmill. This type of cut is defined as a cross-cut. Cross-cut segments from logs, known colloquially as “cookie(s)”, are popular in-home decor, and fine furniture fabrication. Currently, there are no means or provisions on the market that allow for a wooden log to be safely and securely clamped to portable sawmills to allow for cross-cutting.
At least some embodiments described herein comprise an apparatus that may be secured to a portable sawmill's bed. This apparatus safely and securely clamps segmented logs in a vertical position, allowing for a cross-cut to be performed by the saw of the portable sawmill.
In a first embodiment, an apparatus for mounting logs for processing on a sawmill having a log bed defining a log bed plane includes a first plate, a stationary jaw, and movable jaw. The first plate is configured to be fixedly mountable on a log bed of a sawmill, and configured to support a log to be cross-cut. The stationary jaw is fixedly supported on the plate. The movable jaw is supported on the plate, and is configured to move at least in part in a direction parallel to the log bed plane when the first plate is mounted on the log bed. The movable jaw and the stationary jaw are collectively configured to fixedly clamp a log on the first plate in a clamp interior such that a grain direction of the log is normal to the log bed plane.
In a second embodiment an apparatus for mounting logs for processing on a sawmill having a log bed defining a log bed plane includes a first plate, a stationary jaw, a movable jaw, and at least a first lead screw. The first plate is configured to be fixedly mountable on a log bed of a sawmill, and configured to support a log to be cross-cut. The stationary jaw is fixedly supported on the plate. The movable jaw is supported on the plate, and is configured to move at least in part in a direction parallel to the log bed plane when the first plate is mounted on the log bed. The movable jaw and the stationary jaw are collectively configured to fixedly clamp a log on the first plate in a clamp interior such that a grain direction of the log is normal to the log bed plane. The first lead screw is operably coupled to cause movement of the at least one movable jaw in the direction parallel to the log bed plane.
In one exemplary embodiment, the apparatus holds round vertical logs above the bottom cutting plate of a sawmill bed utilizing two grooved (or toothed) jaws that provide multiple points of contact with the log. These multiple contact points create a safe and secure hold on the log. The movable jaw allows the apparatus to secure logs of varying diameters.
In another embodiment, the apparatus includes a main platform configured to span at least partly between bed rails of a portable sawmill, and an adjustable clamping mechanism or other means for securing the log to the platform. Ideally, the log shall be secured with multiple points of contact. In some embodiments, the clamping mechanism includes a set of jaws with grooves ideally resembling a v-shape. The addition of a series of sharp teeth to these grooves may increase the stability of the log during operation. One or more of these jaws may be movable to allow for a variety of sized logs to be placed on the main platform.
At least another embodiment is an apparatus for crosscutting logs that includes a sawmill bed, a saw head including a saw, and a positioning apparatus that clamps logs in a vertical position on the saw mill bed such that the saw can perform a cross-cut on the logs.
The above-described features and advantages, as well as others, will become more readily apparent to those of ordinary skill in the art by reference the following detailed description and accompanying drawings.
The sawmill 20 may in this embodiment includes a saw head 22, a log bed 24, a saw head carriage 25, and a push handle 26. The log bed 24 includes a set of elongate log rails 28 and cross-bunks 30. In this embodiment, the set of log rails 28 includes two parallel metal rails, and the cross-bunks 30 are plates or short rails that extend perpendicularly between the log rails 28. The tops of the cross bunks 30 generally define a log bed plane that maybe substantially parallel to the ground. The cross bunks 30 and log rails 28 are configured to support a log to be cut on the log bed plane.
In general, the saw head 22 is mounted on the saw head carriage 25, and includes a saw blade, not shown. The saw head carriage 25 is movably mounted on the log rails 28 such that the saw head carriage 25 and saw head is capable of moving linearly in a direction parallel to the log bed plane. This direction is referred to as the cut direction 11. The push handle 26 is secured to the saw head carriage 25 and provides a mechanism by which a user may cause the linear movement of the saw head carriage 25 and saw head 22 in the cut direction 11 (and the reverse). The saw head carriage 25 may also include an up/down crank system 32 configured to adjust the vertical position of the saw head 22, thereby adjusting the height of the cut as is known in the art.
It will be appreciated that the sawmill 20 of
Referring again to the example of
Specifically, the stationary jaw 130 is supported on the first plate 110, and the moveable jaw 150 is movably supported on the first plate 110. The movable jaw 150 is configured to move at least in part in a direction parallel to the log bed plane when the first plate 110 is mounted on the log bed 24. The movable jaw 150 and the stationary jaw 130 are collectively configured to fixedly clamp a log on the first plate 110 in a clamp interior 104 such that a grain direction of the log is normal to the log bed plane and cut direction 11. The movable jaw 150 can be adjusted to a position in which the stationary jaw 130 and the movable jaw 150 tightly engage the round log 15 from opposite sides.
The mounting brackets 50 are brackets suitable to firmly attach to the log bed 24 and to the mounting apparatus 100.
Further detail regarding a first exemplary embodiment of the mounting apparatus 100 is provided with reference to
With reference to
The frame 102 includes the first plate 110, a lower platform 112, and first and second spacer brackets 114. The first plate 110 in this embodiment includes a flat steel plate 116, which has two linear track slots 118 and a series of openings 120 defined therethrough. The linear track slots 118 are parallel slots that extend in a direction perpendicular to the cut direction 11. The linear track slots 118 define the travel path of the movable jaw 150. The direction of travel of the movable jaw 150 is referred to as the clamping direction 13. It will be appreciated that the clamping direction 13 need not be perpendicular to the cut direction 11, and may indeed be at none or any angle from the cut direction 11. However, for reasons that will become clearer below, the arrangement of the clamping direction 13 perpendicular to the cut direction 11 increases the accessibility for adjusting the movable jaw 150.
The series of openings 120 are spaced throughout the steel plate 116 and provide tool access therethrough, as will be discussed below. The openings 120 also help reduce the weight the first plate 110 and hence the mounting apparatus 100 overall.
The lower platform 112 of the frame includes a second plate 122 and integrally formed end walls 124a, 124b. The second plate 122 is a flat steel plate having a series of openings 126 defined therethrough. The second plate 122 may have substantially the same length and width as the first plate 110. Each of the end walls 124a, 124b extends upward at least approximately 2 cm, and in this embodiment approximately 6 cm, from opposite ends of the flat second plate 122. Each of the end walls 124a, 124b includes corresponding inward extending shelves 128a, 128b at their respective tops. The first plate 110 is supported on and secured to the shelves 128a, 128b by suitable fasteners.
The openings 126 are sized and configured to receive shafts of suitable fasteners 127, for example, of the mounting brackets 50. (See
The first and second spacer brackets 114a, 114b are suitable U-beams turned on their side. The brackets 114a, 114b in any event have a height corresponding to the height of the end walls 124a, 124b. The brackets 114a, 114b extend in the clamping direction 13 parallel to the end walls 124a, 124b, and are coupled at the top to the first plate 110, and at the bottom to the second plate 122. The brackets 114a, 114b are spaced apart and define a channel therebetween extending in the clamping direction 13. Thus, in this embodiment, the spacer brackets 114a, 114b cooperate with the end walls 124a, 124b to create a space between the first plate 110 and the second plate 122. The spacer brackets 114a, 114b furthermore add strength for supporting a log placed on the first plate 110.
It will be appreciated that in other embodiments, it would be possible to use a single top plate, so long as provision for connecting the top plate to the log bed 24 is provided.
The stationary jaw 130 and movable jaw 150 have respective gripping faces 132, 152 that face toward each other, defining a clamp interior 180 therebetween. In use, a log (e.g. the log 15 of
In further detail regarding the stationary jaw assembly 104, the stationary jaw assembly 104 includes the stationary jaw 130 and a clamp mount 131. The stationary jaw 130 is fixedly fastened indirectly to the first plate 110 via a clamp mount 131, which is in the form of a rectangular bar. The clamp mount 131 provides additional vertical relief of the stationary jaw 130 away from the first plate 110 to improve gripping power with respect to the log. In one embodiment, multiple spacers similar to the clamp mount 131 may be optionally added by the user when further vertical relief is desired or needed.
Structurally, the stationary jaw 130 in this embodiment includes clamp body 138 formed of steel and having a back bar 140, a first wing 136a, and a second wing 136b. The first wing 136a extends from a central point 142 at an angle with respect to the cut direction 13 generally toward the movable jaw 150, and the second wing 136b extends from the central point 142 at a complementary angle with respect to the cut direction generally toward the movable jaw 150, such that the wings 136a, 136b form a concave V-shape. At the central point 142, the wings 136a, 136b are positioned adjacent to the back bar 140. At their furthest extent, the wins 135a, 136b are spaced apart from the back bar 140 and are connected to the back bar 140 via respective end braces 144a, 144b
Returning again generally to
The clamp bearing plate 153 is affixed to the sliding clamp mount 151 and is disposed between the sliding clamp mount 151 and the surface of the first plate 110. The clamp bearing plate 153 is formed of a strong polymer with good sliding and wear properties, such as ultra high molecular weight (UHMW) polyethylene. The clamp mount 151 and clamp bearing plate 153 provide additional vertical relief of the movable jaw 150 away from the first plate 110 to improve gripping power with respect to the log 15.
In this embodiment, both jaws 130, 150 are attached to their respective mounts 131, 151 such that they may be removed for servicing without removing either mount 131, 151.
The movable jaw 150 itself may suitably be similar to the stationary jaw 130. The movable jaw 150 in this embodiment includes clamp body 158 formed of steel and having a back bar 160, a first wing 156a, and a second wing 156b. The back bar 160 has a trapezoidal shape with short end 160a forming the rear of the movable jaw 150, two outwardly angled sides 160b and 160c, and a long end that is not separate, but rather defines a dividing point between the back bar 160 and the wings 156a, 156b.
The first wing 156a extends from a central point 162 at an angle with respect to the cut direction 13 generally toward the stationary jaw 130, and the second wing 156b extends from the central point 162 at a complementary angle with respect to the cut direction 13, and generally toward the stationary jaw 130. As a result, the wings 156a, 156b form a concave V-shape. At the central point 162, the wings 156a, 156b are positioned near the back bar 160. At their respective opposite ends, the wings 156a, 156b are spaced apart further from the back bar 160 but are connected to and supported by the back bar 160 by respective brace bars 162a, 162b. The brace bars 162a, 162b extend as a continuation of the angled sides 160b, 160c of the back bar 160.
The V-shapes of the clamping faces 132, 152 provide the advantage of being able to engage logs of a plurality of diameters (via different sets of the plurality of teeth 134 on the stationary jaw 130 and different sets of teeth 154 on the movable jaw 150). The shapes of the clamping faces 132 and 152 also accommodate the fact that logs are not perfectly round. The V-shapes of the clamp faces 132, 152 can place at least four points of contact on a wide variety of log shapes and sizes. It will be appreciated that other shapes or configurations of the clamping faces 132, 152 not strictly having a V-shape can place multiple contact points on a variety of log shapes and sizes.
Referring again generally to
The lead screw 182 in this embodiment includes a threaded shaft 182a, opposing drive ends 182b, 182c, and opposing shanks 182d, 182e disposed between the threaded shaft 182a and respective drive ends 182b, 182c. The lead screw 182 is rotatably mounted on the first and second terminal blocks 186, 188, and extends therebetween in the clamp direction 13 under the first plate 110. At least the drive end 182b (see
The first terminal block 186 has an opening 186a configured to rotatably receive the shank 182d via the first bushing 190a, and the second terminal block 188 has an opening 188a configured to rotatably receive the shank 182e via the second bushing 190b. The first terminal block 186 is mounted to and between the first plate 110 and the second plate 122 at a position closer to the movable jaw 150 than the stationary jaw 130, and outside the outermost extent of travel of the movable jaw 150. The second terminal block 188 is mounted to and between the first plate 110 and the second plate 122 at a position spaced apart from the first terminal block 186, and preferably is located beyond the innermost extent of travel of the movable jaw 150. In this embodiment, the terminal blocks 186, 188 are disposed at opposite side edges of the first plate 110.
The carrier 184 includes a lead screw nut 184a mounted to a travel plate 184b, for example, by a weldment. The nut 184a has internal threads complementary to those of the threaded shaft 182a, and as a consequence, rotation of the lead screw 182, for example, by the drive end 182a, causes linear movement of the lead screw nut 184 in the clamping (or opposite) direction 13. The travel plate 184b is coupled via fasteners 194a, 194b to the sliding clamp mount 151. The fasteners 194a, 194b pass through the linear track slots 118, and thus may move freely back and forth in the clamping direction 13. A travel plate bearing 196 is affixed to the travel plate 184b and is disposed between the travel plate 184b and the under surface of the first plate 110. The travel plate bearing 196 is formed of a strong polymer with good sliding and wear properties, such as ultra high molecular weight (UHMW) polyethylene.
In operation, the mounting apparatus 100 is first mounted to a sawmill, such as the sawmill 20 of
Once the mounting apparatus 100 is mounted on the log bed 24, the log 15 may be placed in an upright position on the first plate 110 between the movable jaw 150 and the stationary jaw 130. The log 15 may be moved to a position where it contacts the stationary jaw 130. The operator may then use a suitable tool to engage the drive end 182b to rotate the lead screw 182. Rotation of the screw 182 causes the carriage 184 to move in the clamping direction 13. Movement of the carriage 184 causes the sliding mounting plate 151 to move in the clamping direction 13 as well. During this movement, the fasteners 194a, 194b move along the slots 118 in the first plate 110. The operator continues rotating the lead screw 182 until the movable jaw 150 clamps the log 15 firmly against the stationary jaw 130.
It will be appreciated that the width of the slots 118 preferably allow for slight play or rotation of the movable jaw 150 about a vertical axis. To achieve this play, the fasteners 194a, 194b are preferably slightly loosened. The play or slight rotation of the jaw 150 helps accommodate gripping logs that are not circular.
Once clamped, the operator can use the up/down crank system 32 to adjust the height of the saw head 22 (which includes a blade, not shown separately) and thus the height of the cut. It will be appreciated that the height should be at least sufficient to avoid contact between the blade and the mounting apparatus 100. To this end, in this embodiment, the mounting apparatus 100 include minimum cut height indicator 198 disposed on the first plate 110. The minimum height cut indicator 198 is a plastic knob that is only slightly taller than the height of all steel parts on the mounting apparatus 100. Because the height from the first plate 110 is not tied to the height scale on the sawmill 20 itself, it may not be obvious to the operator how low the saw blade may be set on the final set of cuts. If the blade of the sawmill 20 makes contact the indicator 198, then that signals to the operator that the cut is too low. If the operator progressed into the cut after that point, the blade could engage steel fasteners, thereby causing damage.
In any event, after the vertical position of the saw head 22 is set, the operator may then start the sawmill engine or motor, and move the working saw head 22 along the cut direction 11 to cross cut the log 15.
The operator may then retract the saw head 22 back away from the log 15, adjust the saw head 22 downward by a desired amount, and perform an additional cross-cut of a another cookie. This process may be repeated until the log 15 can no longer be cross-cut. Once the cross-cutting of the log 15 is completed, the operator may loosen the clamping force by reverse rotation of the lead screw 182. As discussed above, if the operator desires to perform lengthwise cuts on horizontally disposed logs, the mounting apparatus 100 and mounting brackets 50 may be decoupled from and removed from the log bed 24.
It will be appreciated that the above-described embodiments are merely illustrative, and that those of ordinary skill in the art may readily devise their own implementations and modifications that incorporate the principles of the present invention and fall within the spirit and scope thereof.
By way of example, it will be appreciated that the orientation of the two (or more) jaws 130, 150 may be placed anywhere on the main platform. It is not necessary for the jaws to be aligned parallel to the direction of the sawmill blade travel. The apparatus could be installed on a portable sawmill bed so that the clamping direction of the jaws was normal to the sawblade. Additional jaws or alternate clamping methods could be used in any orientation to increase stability of the log.
In another example, as mentioned above, different mounting brackets may be used. For example,
The upright plates 210 are spaced such that the seat 212 is adapted to relatively tightly receive the bottom of a bunk of a sawmill, such as any of the bunks 30 of
With reference to
The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 63/158,394, filed Mar. 9, 2021, the entirety of which is in incorporated herein by reference.
Number | Date | Country | |
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63158394 | Mar 2021 | US |