WO2001041982A2

WO2001041982A2 - Log saw clamp apparatus and method

Info

Publication number: WO2001041982A2
Application number: PCT/US2000/042482
Authority: WO
Inventors: Tad T. Butterworth; Jeffrey L. Johnson; Eric J. Lumberg
Original assignee: C.G. Bretting Manufacturing Company, Inc.
Priority date: 1999-12-03
Filing date: 2000-12-01
Publication date: 2001-06-14
Also published as: BR0016110A; AU4710101A; CA2393544A1; MXPA02005573A; EP1237684A2; WO2001041982A3; WO2001041982A9

Abstract

The log saw clamp (10) of the present invention includes a brace (34) and at least one jaw (38) connected to an actuation member (30). The preferred embodiment has two jaws (26) supporting the logs from below, the brace (34) restraining logs from above and the actuation member connected to both ends of the brace. The diameter of the log receiving area (110) can be adjusted by moving the actuation members. Linear movement of the actuation members causes the jaws to pivote and the brace to translate such that the diameter of the log receiving area is increased or decreased. The jaws are pivotally connected to the actuation member via jaw mounts (74). The actuation member is preferably moved with a turn wheel (90) and gear assembly (94). The brace is spring loaded (42) to the actuation member. The jaws can be interchanged with differently sized and shaped jaws to accomodate differently size logs.

Description

LOG SAW CLAMP APPARATUS AND METHOD

FIELD OF THE INVENTION This invention relates generally to clamping methods and apparatus. More particularly, the invention relates to clamping methods and apparatus for releasably securing rolls of web material.

BACKGROUND OF THE INVENTION

Several web material products are initially produced in logs for ease of manufacture. As used herein and in the appended claims, the term "web" material refers to any porous or non-porous product which can be found in sheet form, regardless of length or width. Although the preferred embodiments of the present invention described below are with reference to operations performed upon webs of material made of any paper product (which includes without limitation paper toweling, toilet paper, napkins, tissues, etc.), other illustrative examples of web material products include foil, film, fabric, cloth, cellophane, wrapping paper, wax paper, etc.

A log is a rolled product of any web material having any set of dimensions. In logs of paper product web material, logs are generally sawed into smaller rolls to be used by consumers. Automation of the sawing process allows the manufacturer to achieve satisfactory production rates. In many conventional log sawing devices, the sawing process generally involves a cutting blade, a clamp to hold the logs, and an advancing mechanism to move the logs.

Logs of paper product are often not very strong radially, and are typically clamped to provide support and to prevent the logs from being crushed by the saw. Such logs are preferably clamped on both sides of the blade to facilitate a straight cut through the logs.

Most prior art clamps use elastic straps, flexible cylindrical strips, guide troughs, semi-cylindrical shells, or grippers to support a log during the sawing process. Examples of such conventional log clamping mechanisms are disclosed in United States patent number 5,509,336 issued to Biagiotti, number 5,357,833 issued to Biagiotti, number 5,647,259 issued to Biagiotti, number 5,038,647 issued to Biagiotti, number 5,315,907 issued to Biagiotti, and number 3,049,954 issued to Barlament et al., each of which are incorporated herein by reference insofar as they relate to log clamping mechanisms. Each of these clamping assemblies has one or more significant design limitations. Some examples of problems or limitations in the prior art devices include generally weaker designs, speed limitations caused by inherently slower designs and fiictional engagement, excessive wear and stress on parts, and complex assemblies requiring numerous parts.

Weaker log clamp designs typically result in clamps which are difficult to adjust or produce ineffective clamping results. Many prior art clamping devices allow slight movement during the clamping process which can cause bias cutting or product flaws. Because upstream equipment is usually capable of producing logs of varying diameter, such clamps should be manually or automatically adjustable to accommodate logs having different diameters. However, several prior art clamps are not easily adjustable. Those prior art clamps which are adjustable generally require extra tooling or screws to set the clamps in desired positions.

An example of problems arising with respect to clamp adjustability is found in the semi -cylindrical shell clamp disclosed in the Biagiotti '907 patent. This clamp has one fixed side and one spring-loaded resiliently mounted side. The spring-loaded resiliently mounted side requires the adjustment of small screws to alter the compression of the spring and the diameter of the clamp. This system of adjustment requires the operator to stop the saw while changing the setting because of the proximity of the screws to the saw. Further, this semi- cylindrical shell device can only accommodate slight changes in log diameter due to the small range of movement of the resiliently mounted side. Because there are only two shells, a large variation in the log diameter causes the edges of the shells to cut into a larger log, while a smaller log does not receive an adequate clamping force and clamp forces would be undesirably concentrated. Either one of these situations can cause product flaws.

Another common design problem in the prior art involves vertical clamp adjustment. In most conventional log saws, the log is advanced on guides at a fixed height. These guides support the bottom of the log. When logs of varying diameter are passed through the system, the bottoms of the logs are each located at a constant height rather than the centers of the logs. Some prior art clamps can be adjusted to change the diameter of the clamp while keeping the center of the clamp unmoved. When the diameter of such a clamp is adjusted, the bottom of the clamp must move. Therefore, these clamps must be mounted to move vertically as well as radially to align the bottom of the clamp diameter with the bottom of the incoming log. This extra motion step makes adjustments more time consuming and complicates the clamp design. An example of such design is disclosed in the Biagiotti '336 patent. Most prior art clamps can be grouped into two general categories: constant pressure clamps and intermittent clamps. Constant pressure clamps use a spring or other resilient member to apply constant pressure on the log or to provide a resilient restraining structure about the log. Intermittent clamps only clamp the log during cutting operations and then release to allow the log to advance forward for the next cut. The intermittent clamps experience rapid cycle times between the clamp and release positions. This constant cycling creates two major problems: speed limitations and increased wear on parts.

Because the intermittent clamps must clamp the log for each cut and then release the log for advancement, the speed of the log saw is limited by the speed of the clamp. Even with rapid cycle times, log saws with intermittent clamps are slower than log saws with constant pressure clamps.

Due to the rapid cycle times of intermittent clamps, parts are exposed to wear and tear from constant rubbing. A prior art device that exhibits problems resulting from excessive wear and friction between parts is the flexible cylindrical strip and elastic strap clamp disclosed in the Biagiotti '833 patent. This clamp includes an elastic belt that is pulled down over two contacting strips with rapid cycle times to clamp the logs. The constant friction between the belt and the strips slows the clamp's adjustment to different diameter logs and can cause the belt to wear out.

In order to possess flexible properties, the strips must be relatively thin. Due to the thin construction of the strips, the strips are easily bent or damaged. The flexible strips also can suffer from plastic deformation and lose their resistive properties because of the constant cycling. These strips are especially likely to deflect when a hard log is clamped. As a result of the above limitations, these parts may need to be frequently replaced.

Another example of a prior art device which has wear and tear limitations is the gripper clamp disclosed in the Biagiotti '647 patent. In this clamp, a reciprocating actuator rotates an outer ring. Grippers are attached to the outer ring via pins which fit into grooves in the ring. When the ring rotates, the grooves force the pins and the grippers back and forth. The constant reciprocating wears down the contacting surfaces of the ring and grippers.

Wear and tear on parts is closely related to the problem of overly complex designs. Several prior art devices include numerous small parts and assemblies which are difficult to access in the log clamp device. Also, these complex designs are relatively expensive to manufacture, assemble, maintain, and repair. The deterioration of parts due to friction and wear creates significant maintenance problems of accessing small and often concealed parts and replacing them in close quarters. Replacing the parts is also time consuming and typically requires the log saw to be stopped while this maintenance is being performed. The inability to consistently run the log saw therefore costs the manufacturer a significant amount of money and increases machine inefficiency.

In light of the problems and limitations of the prior art described above, a need exists for a log saw clamp that is easily adjustable, substantially rigid, strong, effectively clamps the log, does not require that logs be slowed during cutting operations, has relatively few moving parts, does not have an overly complex design with small intricate parts, has a design permitting ease of manufacture and maintenance, is easy to adjust without requiring system shutdown, and which has a minimum number of moving parts subject to wear. Each preferred embodiment of the present invention achieves one or more of these results.

SUMMARY OF THE INVENTION

The log saw clamp device of the present invention includes at least one jaw and a brace. The jaw and brace are preferably both coupled to an actuation member. Movement of the actuation member thereby causes movement of the jaw and brace. The jaw is preferably mounted for rotation about a pivot point. Preferably, the jaw has a curved side which contours to the shape of the log and which provides for support of the log.

The jaw preferably includes a jaw mount and a jaw member. Preferably, the jaw member is coupled to the jaw mount using a quick change connection and can be interchanged with at least one other jaw of a different size to modify the clamp for different log types (e.g., logs having a significantly different diameter). A quick change jaw is also easier to replace when parts of the clamp assembly become worn or are damaged. Movement of the actuation member can adjust the jaw to modify the clamp for logs with a moderately different diameter.

The actuation member is preferably moved by a turn wheel and gear assembly. While many conventional assemblies and devices can be used to move the actuation member for adjusting the jaws, the turn wheel and gear system allows for precise adjustments. The turn wheel and gear system also permits adjustments to be made on the clamp assembly while the saw is performing cutting operations, thereby avoiding the need to stop log sawing operations to adjust the clamp.

In the preferred embodiment, the clamp provides a constant clamping pressure on the logs and movement of the actuating member adjusts the diameter of the clamp. Because the clamp applies a constant pressure, the speed of the log saw is not limited by the clamp (such as in prior art intermittent clamps described above). However, the clamp can easily be modified for automatic cyclical movement of the actuating member which would intermittently clamp the logs.

The brace is mounted for translation and can be mounted to the actuation member for movement with the actuation member and the jaws. Preferably, the brace has a curved surface to provide sufficient contact with the log as it moves through the clamp. More preferably, the brace is resiliently mounted with springs to accommodate slight variations in log diameters and to apply an adequate clamping force on the logs.

In operation of the present invention, linear movement of the actuation member preferably causes rotational movement of the jaw and translational movement of the brace to increases or decrease the diameter of the clamp. The diameter of the clamp can preferably be adjusted while keeping a point on the circumference of the clamp relatively constant. This feature eliminates the need for vertical adjustment of the clamp because the logs usually enter the clamp with the bottom edge of the logs at a constant level regardless of the logs diameter.

The log saw clamp of the present invention has a robust design with relatively few small or moving parts. This substantially rigid design allows the clamp to apply a higher clamping force and makes the clamp more durable. Having fewer complex and intricate parts makes manufacture, assembly and maintenance easier.

Further objects and advantages of the present invention, together with the organization and manner of operation thereof, will become apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings, wherein like elements have like numerals throughout the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is further described with reference to the accompanying drawings, which show a preferred embodiment of the present invention. However, it should be noted that the invention as disclosed in the accompanying drawings is illustrated by way of example only. The various elements and combinations of elements described below and illustrated in the drawings can be arranged and organized differently to result in embodiments which are still within the spirit and scope of the present invention.

In the drawings, wherein like reference numerals indicate like parts:

FIG. 1 is a perspective view from below of a log saw clamp assembly according to a preferred embodiment of the present invention;

FIG. 2 is a front elevational view of the log saw clamp assembly shown in FIG. 1, showing the log saw clamp in a fully opened position;

FIG. 3 is a front elevational view of the log saw clamp assembly shown in FIGS. 1 and 2, showing the log saw clamp in a fully closed position; and

FIG. 4 is a side elevational view of the log saw clamp assembly shown in FIGS. 1-3.

DETAILED DESCRIPTION A preferred embodiment of the log saw clamp assembly 10 of the present invention is illustrated in FIG. 1 as it would appear in a log saw apparatus. The present invention can be used with any conventional log saw device. One such log saw device is shown (by way of example only) in the figures. In the illustrated log saw device, logs are conveyed to a cutting position with respect to a log saw blade 14 via conventional log saw guides 22 along which run a chain 48 and a series of log saw fingers 50 having paddles 54 for pushing the logs. The chains 48 run around sprockets 46 at the ends of the log saw guides 22 to provide for continuous passage of fingers 50 and paddles 54 along the guides. The conveyor assembly 18 defined by the log saw guides 22, the chain 48, the log saw fingers 50, and the paddles 54 is driven in by a conventional device such as a motor controlled by a system controller. For purposes of increasing the speed of product output, many systems such as that illustrated in the figures have multiple log lanes (limited at least in part by the size of the log saw blade 14) through which two or more logs pass and are cut simultaneously. However, systems having only one lane are also possible. The conveying assemblies for the lanes are typically of the same design and operate in the same manner. The particular conveying device employed does not form an important feature of the present invention, and as noted above, other well-known conveying devices and drives can be used with the invention. Such alternative conveying devices include without limitation belt and pulley assemblies, slides, conveyor belt assemblies, and the like.

Because lateral forces are usually exerted upon each log as it is being cut by the blade 14, it is generally necessary to restrain the log from movement during cutting operations. To this end, a log saw clamp according to the present invention is preferably located on both sides of the blade's cutting path, with a clearance therebetween adequate for the blade 14 to pass between the clamps and to cut the log therein. However, it is possible to employ only one such clamp on either side of the log saw blade.

The log saw clamp assembly 10 of the present invention includes an actuation member 30, a brace 34, and at least one jaw 38 mounted for rotation about a pivot 86 which preferably supports the jaws 38 in the clamp assembly 10. The pivot 86 is preferably secured in a conventional fashion against movement with respect to the frame of the assembly (not shown), such as by one or more arms, braces, or frame members (also not shown) extending laterally from beside the jaws 38 and supporting the pivots 86 for rotation. Preferably, there are two rotation jaws 38 for each brace 34 as illustrated in the figures. Other embodiments of the present invention can have only one jaw, one fixed jaw (not capable of rotation) and one jaw mounted for rotation, or any combination of fixed and rotatablejaws.

Although the jaw 38 can be a one-piece element, the jaw 38 is preferably made of at least two pieces and most preferably three pieces: a jaw mount 74 and one or more jaw members 26 (but most preferably two jaw members 26 as shown in the figures). An important feature of the present invention is the speed with which the jaw members 26 can be removed and replaced as will be discussed in more detail below. Therefore, in preferred embodiments of the present invention, the jaw members 26 are preferably fastened to the jaw mounts 74 by releasable fasteners such as threaded fasteners, pins, clamps, and the like. Most preferably however, the jaw members 26 are releasably attached to the jaw mounts 74 via a number of bolts 36 passed through matching holes in the jaw members 26 and the jaw mounts 74. To assist and speed the process of interchanging jaw members 26, the jaw mounts 74 and the jaw members 26 each preferably have a key and groove connection (or other quick release and connect mechanism) as indicated in FIGS. 2 and 3 by reference numeral 40 for positioning and aligning the jaw members 26 upon the jaw mounts 74.

The jaw member portion of the jaw 38 defines a surface which acts to restrain the log as it is being cut by the saw blade 14. Preferably, the jaw member 26 is therefore an elongated body which has a concave surface facing the log being cut, and runs substantially the entire length of the clamp assembly 10. Alternatively, this surface can be virtually any shape desired, such as flat, ribbed, multi-sided, V-shaped, or even concave (in which case each jaw member 26 would likely contact the log along one longitudinal line during cutting operations). Similarly, the elongated shape of the jaw member 26 can be shortened or lengthened considerably to produce a more compact or longer clamp as desired. The elongated concave surface illustrated in the figures is preferred because it provides support for the log while in the clamp (when the jaw member 26 at least partially supports the log in the clamp as discussed below) and provides a substantial and smooth contact with the log being cut. The jaw members 26 are preferably made from a rigid or substantially rigid material such as aluminum, steel, iron, or other metal, composites, plastic, and the like.

However, the jaw members 26 can be made from semi-rigid material to permit slight deformation under pressure or impact, such as from the log during cutting operations. These semi-rigid materials include without limitation rubber, urethane, and other synthetic materials.

To control the jaw member 26 at both ends, the jaw 38 preferably has a jaw mount 74 attached to or depending from each end of the jaw member 26. Each jaw mount 74 is attached to a respective actuation member 30 via a pin 78 as can best be seen in FIG. 1. The jaw mounts 74 are preferably elongated in shape as shown in the figures, thereby providing a torque arm against which force can be exerted to pivot the jaws 38 about the pivots 86.

However, it should be noted that the jaw mounts 74 can be virtually any shape having a portion which is located a sufficient distance from the jaw member 26 for an applied torque to pivot the jaws 38. With reference to FIGS. 2 and 3, it can be seen that when the jaws 38 are pivoted about the pivots 86, the jaw members 26 are moved toward and away from an area 110 into which logs are received for cutting. The log receiving area 110 is an area which is at least partly bounded by the jaw members 26 and the brace 34. By pivoting in this manner, the jaw members 26 have a component of movement which is radial with respect to the log receiving area 110 and the axis 12 therein and a component of movement which is tangential with respect to the log receiving area 110 and the axis 12. Therefore, the jaw members 26 preferably each follow a substantially arcuate path of motion toward and away from the log receiving area 110 and the axis 12 when the jaw members 26 are pivoted as just described. Because the jaw member 26 preferably face each other and are pivoted toward one another in their movement, the paths of the jaw members 26 converge toward the log receiving area 110 and the axis 12 as the clamp assembly 10 is tightened (described in more detail below).

The brace 34 of the present invention is mounted adjacent to the jaws 38 (and more specifically, adjacent to the jaw members 26) as shown in FIGS 1-3. Like the jaw members 26, the brace 34 preferably extends substantially the entire length of the clamp assembly 10 and preferably has a convex curved surface facing logs in the log receiving area 110. The brace 34 can instead present a straight or substantially straight surface to logs in the log receiving area 110, and can take any of the surface shapes discussed above with reference to the jaw members 26. The brace 34 is preferably made of metal, and is more preferably made of aluminum, but can be made of any material discussed above with reference to the jaw members 26.

Where multiple lane log saw systems are used as shown in the figures, the brace 34 preferably extends as a one-piece element across adjacent log saw clamp assemblies 10. However, dedicated braces 34 for each lane can instead be employed if desired.

The brace 34 is preferably mounted within the clamp assembly 10 by a number of clamp rods 58 attached to the brace 34. The clamp rods 58 can be rigidly attached to the brace 34 in a number of conventional manners, such as by being welded, bolted, press fitted, and the like. However, the clamp rods 58 are more preferably received within apertures 60 in the brace 34, with end portions 66 of the clamp rods 58 having a slightly smaller diameter and being capped or fitted with nuts 70 to hold the brace 34 upon the clamp rods 58. Most preferably, conventional springs 42 are fitted upon the end portions 66 of the clamp rods 58 and are located between the brace 34 and a shoulders on the clamp rods 58 to exert a spring- biased force against the brace 34 for limited movement of the brace 34 along the clamp rods 58. Other embodiments of the present invention have a spring 42 or other resilient material on both sides of the brace 34. The ability of the brace 34 to move under spring force in this manner is desirable particularly when logs of slightly varying diameter are passed into the log receiving area 110, in which case slightly larger diameter logs will still be admitted into the log receiving area 110. One having ordinary skill in the art will appreciate that many other conventional springs and spring-loaded assemblies are capable of providing the biasing spring force just discussed.

In alternate embodiments of the present invention, the clamp rods 58 can be replaced by a number of other elements capable of supporting the brace 34 in position beside the jaws

38. For example, the clamp rods 58 can instead be plates, bars, tubes, or other elements extending from the brace 34 to the actuation member 30 and connected to each in a conventional manner. However, such alternative embodiments still preferably have spring- loaded assemblies as described above and most preferably have members which extend through the brace plate and which are spring loaded in a similar manner as the clamp rods 58 of the illustrated preferred embodiment.

The clamp rods 58 are preferably movable (as will be discussed in more detail below) to translate the brace 34 toward and away from the jaws 38. Accordingly, and with reference to FIGS. 2 and 3, the jaws 38 and the brace 34 together define the log receiving area 110 and act to restrain logs being cut from movement outside of the log receiving area 110. Because the brace 34 is movable substantially upward and downward via movement of the clamp rods 58, and because the jaws 38 are pivotable toward and away from the log receiving area, the brace 34 and the jaws 38 can be placed in a range of positions from a wide position as shown in FIG. 2 (with the jaws 38 rotated apart and the brace 34 translated away from the jaws 38) to a tightened position as shown in FIG. 3 (with the jaws 38 rotated together and the brace 34 translated toward the jaws 38). The preferred manner in which the motion and positioning of these parts is created will now be discussed.

To provide a simplified log clamp design, movement of the brace 34 via the clamp rods 58 and movement of the jaws 38 are preferably accomplished by the same element or mechanism. In the preferred embodiment of the present invention illustrated in the figures, this is performed by movement of the actuation members 30. The actuation members 30 are preferably plates, panels, or like elements to which are attached the clamp rods 58 and the jaws 38. The clamp rods 58 are preferably attached in a conventional manner to opposite sides or edges of the actuation members 30, such as by bolts, screws, or other threaded fasteners, by welding, brazing, gluing, etc. Most preferably, bolts 72 are passed through apertures in the clamp rods 58 and into matching threaded apertures in the actuation members 30. The jaws 38 are preferably attached to the actuation members 30 via pins 78 extending from the actuation members 30 and into elongated apertures 82 in the jaws 38 (and more preferably in the ends of the jaw mounts 74 located a distance from the pivots 86).

The actuation members 30 are preferably slidable along guides 114 flanking the actuation members 30. The guides 114 can take many forms for a sliding, gliding, or rolling relationship with the actuation members 30. For example, the guides 114 can be C-shaped rails into which the edges of the actuation members 30 are slidable received or into which pins, posts, or extensions of the actuation members 30 are slidably received as shown in the figures, a bearing track into which the actuation members 30 are mounted for rolling movement along the bearing track, rods or bars telescopingly received within apertures of the actuation members 30 running along the length of the actuation members 30, etc.

Where multiple lane log saw systems are used as shown in the figures, the actuation members 30 preferably extend as one-piece elements across adjacent log saw clamp assemblies 10. However, dedicated actuation members 30 for each lane can instead be employed if desired. In such case, guides similar to those described preferably flank each actuation member in the same or similar manner to the guides 114 flanking the two lane system illustrated in the figures.

The elongated apertures 82 in the jaws 38 are preferably slanted with respect to the path of motion of the actuation members 30 as shown in the figures. As the actuation members 30 are moved along the guides 114, the pins 78 ride against the opposing surfaces 84 of the elongated apertures 82 and thereby cause the jaws 38 to pivot about their pivots 86.

By moving the actuation members 30 along the guides 114, the clamp rods 58 and the brace 34 attached thereto translate toward or away from the jaws 38 while the jaws 38 pivot toward or away from one another about their pivots 86. Therefore, such movement of the actuation members 30 tightens or loosens the clamp assembly 10 for accommodating logs of different diameters. As described above, the path of motion of the jaws 38 is preferably arcuate, having a component of motion which is radial and a component of motion which is tangential with respect to the log receiving area 110 and the axis 12 therethrough. The jaws 38 of the clamp assembly 10 preferably converge toward one another along their arcuate paths as the clamp assembly 10 is tightened.

It will be appreciated by one having ordinary skill in the art that the actuation members 30 can take a number of forms also capable of moving the pins 78 as described for rotating the jaws 38 while translating the clamp rods 58 and the brace 34. For example, the actuation members 30 can be plates as illustrated in the figures, rods or bars extending between the guides 114 and mounted for movement in the guides 114, or even fingers secured to and extending laterally from the clamp rods 58 (in which case the fingers can have bent ends which serve the same functions as the pins 78 riding within the elongated apertures 82 of the jaws 38). Such alternative elements serve the same functions as the plate-shaped actuation member 30 described above and illustrated in the figures.

Although the jaws 38 are preferably pivoted by camming motion of the actuation member pins 78 within the elongated apertures 82, the jaws 38 can be pivoted in a number of different manners. For example, rather than a set of pins 78 riding within elongated apertures 82 of the jaws 38, the jaws 38 can have pins riding within grooves in the actuation members 30. Alternatively, pins or cam followers extending from the actuator members 30 can ride alongside the dogleg portions of the jaws 38 shown in the figures, thereby guiding the jaws 38 between the pins to rotate the jaws as the actuator members 30 are moved. In yet another alternative embodiment, the actuation member 30 shown in the figures can have a raised portion in the form of a wedge between the dogleg portions of the jaws 38, whereby movement of the actuation member 30 in one direction causes the wedge to force the jaws 38 apart, while movement of the actuation member 30 in an opposite direction permits the jaws 38 to return to their positions shown in FIG. 2 by (for example) spring force from springs connecting pairs of jaws 38 together. Many other alternative devices and assemblies exist for pivoting the jaws 38 about their pivots 86, each of which preferably simultaneously moves the clamp rods 58 to translate the brace 34. Also, these alternative devices and assemblies need not necessarily rely upon camming contact between the actuation members 30 and the jaws 38 as is the case with the embodiments just described. Such alternative devices and assemblies fall within the spirit and scope of the present invention.

It should be noted that still other alternative devices and assemblies can be used for pivoting the jaws 38 about their pivots but which do not simultaneously move the clamp rods 58. For example, the clamp rods 58 need not necessarily be attached to the actuation member 30 for movement therewith, and can instead be mounted to a frame of the system. The actuation member 30 can then be a bar located immediately beneath the jaws having a wedge shape or ramped surfaces riding against the jaws 38 in movement of the actuation member 30 to push the jaws 38 apart under spring force as described above. Alternatively, the jaws 38 can ride upon pins attached to the clamp rods and laterally extending within elongated apertures 82 in the jaws 38, in which case a bar or other element located immediately beneath the jaws 38 and riding within the guides 114 can be movable to push the jaws 38 upward in FIGS. 2 and 3 to pivot about the pivots 86 while riding upon the pins. Downward movement of the bar would permit the jaws 38 to fall under gravity to their positions shown in FIG. 2. While not preferred due to the lack of brace movement for a better enclosed log receiving area 110, these alternate embodiments also fall within the spirit and scope of the present invention.

A number of different devices and systems exist for moving the actuation member 30 as described above (preferably within guides 114). In the preferred embodiment of the present invention, the actuation element 30 is adjusted via a turn wheel 90 which preferably has a gauge or counter for a user to identify the diameter at which the log clamp assembly 10 is set. The turn wheel 90 is preferably connected to the actuation element 30 through a gearing assembly 94. In this assembly, turning the turn wheel 90 moves the actuation element 30 through the range of positions between a loose position as shown in FIG. 2 and a tight position as shown in FIG. 2. In particular, bevel gears turned by the turn wheel 90 transmit rotational motion to a threaded rod 106 received within a threaded hole 102 in the actuation member 30 (or in an internally-threaded member attached in a conventional fashion to the actuation member 30). Such an assembly permits a user to precisely position the actuation member 30 at desired heights, and thereby to precisely position the jaws 38 and brace 34 in a range of clamping positions between and including the positions shown in FIGS. 2 and 3. The gear assembly 94 illustrated can be driven manually or automatically via a motor preferably connected to a controller.

One having ordinary skill in the art will recognize that many alternative systems can be used to adjust the position of the actuation member 30 for tightening and loosening the clamp assembly 10. For example, the actuation member 30 and attached clamp rods 58 can be moved by one or more electronic, hydraulic, pneumatic, or other actuators attached to the actuation member 30 or clamp rods 58 to exert motive force of the actuation member 30 or clamp rods 58, can be moved by a chain and sprocket or belt and pulley assembly attached to and alongside the actuation member 30 or clamp rods 58, etc. Any of these alternative systems can be operated by hand, but are preferably operated automatically via a controller. Due to the simplicity of the clamp design, the clamp assembly 10 can be actuated (i.e., the actuation member 30 and clamp rods 58 moved up or down) very quickly. Therefore, the clamp assembly 10 can be used as a constant pressure clamp or as in intermittent clamp in which a controller rapidly actuates the clamp assembly 10 to open and close with each cut made in a log. Although it is most desirable to employ one gear assembly for moving the actuation members 30 and the clamp rods 58 together, alternative assemblies in which the clamp rods 58 are not secured to the actuation members 30 and/or are movable independently of the actuation members 30 can employ different gear assemblies for the actuation members 30 and the clamp rods 58. Such a design permits greater control over the clamp assembly 10 in that it permits a user to separately adjust the positions of the brace 34 and the jaws 38. As mentioned above, other well-known height adjustment devices and assemblies can be used for adjusting the clamp rods 58 and for adjusting the actuation members 30 in lieu of the gear assembly design illustrated in the figures.

In FIGS. 2 and 3, a gear assembly 94 is shown located only on one side of the actuation member 30. Additional gear assemblies 94 (or other such devices and assemblies capable of moving the actuation member as discussed above) can be connected to other parts of the actuation member 30 and the clamp rods 58 to assist in actuation member movement - particularly for larger or heavier clamp assemblies. Where multiple lane log saw systems are used and have separate and dedicated actuation members 30 for each lane, each lane can be provided with a gear assembly or other moving device or assembly.

FIGS. 2 and 3 demonstrate one example of turn wheel location in the log clamp assembly 10. In these figures, the rum wheel 90 is shown located at the level of the gear assembly 94. FIG. 4 demonstrates another location of the turn wheel 90, in which the turn wheel 90 is located at a higher point by being connected to the gear assembly 94 via a rum shaft 98. Because log saw devices are typically mounted close to floor level, the location of the turn wheel 90 shown in FIG. 4 is preferred. The shaft 98 serves the purpose of moving the turn wheel 90 to a more convenient location for adjustment.

Preferably, the operator or controller adjusts the clamp assembly 10 to the proper diameter, such as by using the turn wheel 90. When the jaws 38 are rotated and the brace 34 is translated to tighten the clamp assembly 10, the jaws 38 rotate and the brace 34 translates toward a reference line or axis 12 of the clamp 10 running parallel to the log receiving area 110 (see FIGS. 2 and 3). The reference line or axis 12 is referred to herein and in the appended claims only for ease of device description, and does not imply that the reference line or axis is necessarily at a center point of the log receiving area or that it necessarily remains stationary (e.g., a set distance from the log saw guides 22) through the adjustment range of the clamp assembly 10. The reference line or axis 12 simply refers to a line in the log receiving area 110 which is substantially parallel to logs received in the clamp assembly 10. The spring loaded brace 34 applies an adequate force to hold logs entering and being cut within the log receiving area 110 relatively steady, yet enables log advancement. The conveyor assembly 18 preferably advances each log into the log receiving area 110 at a nearly constant speed. Because the clamp assembly 10 of the present invention can be adjusted without stopping cutting operations, the clamp assembly 10 can be adjusted between runs of logs having the same diameter or can be adjusted each time a cut made on the log. Also, the clamp assembly 10 can be adjusted to leave a slight clearance between the jaws 38, the brace 34, and the log surface, or can be adjusted to exert a clamping force upon the log during each cut.

The embodiments described above and illustrated in the drawings are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention as set forth in the appended claims.

For example, the log saw clamp assembly 10 is preferably oriented in the manner illustrated in the figures. However, the log saw clamp assembly 10 can be arranged in almost any orientation, such as upside down and sideways with reference to the figures. The log saw clamp assembly 10 can even be mounted so that logs pass horizontally through the system or vertically. Therefore, the jaws 38 of the assembly 10 need not physically support the logs therein, depending upon the particular orientation of the jaws with respect to ground (i.e., if the assembly 10 were upside down, the brace 34 would support the weight of the log in the assembly).

Although a jaw 38 running substantially the entire length of the clamp assembly 10 is preferred, this feature is not a requirement to practice the present invention. Specifically, the wedge-shaped jaw members 26 of the jaws 38 can be replaced by a separate jaw member for each jaw, in which case the front jaws shown in FIGS. 1 and 4 would have a pair or jaw members and the rear jaws would have their own pair of jaw members. The two jaws 38 for each clamp assembly 10 of the preferred embodiments would be effectively replaced by two front jaws and two rear jaws for each clamp assembly 10. Such a design permits jaws to be used which are much shorter than the elongated jaws illustrated in the figures, but at the cost of somewhat less support and stability for logs within the assembly.

As mentioned above, each jaw 38 is preferably made of two elements: a jaw member 26 and a jaw mount 74. In highly preferred embodiments of the present invention, the jaw members 26 are removable from the jaw mounts 74 by a user. The connection between each jaw member 26 and its respective jaw mount 74 is therefore preferably via any type of conventional releasable fastener. For example, the pivots 86 can be removable to disconnect the jaw mounts from the jaw members 26. These pivots 86 can be used alone or in combination with other removable fasteners (such as threaded fasteners, pins, and the like passing through the jaw mounts 74 and the jaw members 26). By permitting removal of the jaw members 26, a user can replace the jaw members 26 with one of a series of jaw members

26 having different shapes, such as jaw members having different radii of curvature to better match logs to be run through the assembly. The other jaw members 26 can have a variety of different shapes and surfaces to accomplish different tasks or to better suit different types of logs being cut. Certain jaw members 26 can be better suited for clamping logs of synthetic material, for exerting higher gripping force against the logs, for handling logs having varying sensitivity to scuffing or damage, or for increased or decreased deformation during clamping if desired.

For the same purposes as just described, preferred embodiments of the present invention permit the user to remove and replace the brace 34 with braces of different shape and size. Accordingly, the brace 34 is preferably secured to the ends of the clamp rods 58 via removable nuts or other conventional removable fastening elements capable of securing the brace 34 in place upon the clamp rods 58.

As indicated above, the present invention is not limited to embodiments in which two rotatablejaws and one brace act to clamp logs in the log receiving area. Although the two- jaw system is preferred (particularly in light of the conveyor assembly arrangement where paddles 54 extend between the jaws 38 and into the log receiving area 110), other conveyor assembly designs permit different jaw and brace arrangements. For example, in one-jaw clamp, the brace 34 preferably encircles the log receiving area 110 more fully than shown in the figures, such as three-quarters or two-thirds around the log receiving area 110, with the jaw 38 extending around the remainder of the log receiving area 110. In another embodiment, three, four, or even more jaws 38 are located about the circumference of the log receiving area 110, and can occupy more or less of the circumference of the log receiving area 110 as desired. In yet another embodiment of the present invention, the brace 34 can be made of two or more sections which can be separated from one another, located in different locations about the circumference of the log receiving area 110, and even be separated from one another by one or more jaws 38. In short, although a one-piece brace and two-jaw clamp assembly is preferred, alternative embodiments can employ more braces or brace sections and can have one, three, or more jaws moving with respect to the brace(s) in the manner described above to clamp and unclamp logs in the log receiving area 110. In all such cases, the jaws 38 preferably operate via rotation and the brace(s) 34 preferably operate via translation in the manners described above with respect to the preferred embodiments of the present invention. It should also be noted that where multiple jaws 38 are employed, the jaws 38 need not be of the same size or shape, nor need they occupy the same amount of circumference about the log receiving area 110. This is true also for those embodiments of the present invention in which multiple braces or brace sections are used.

Claims

What is claimed is:

1. A log saw clamp for clamping logs, the log saw clamp comprising: a jaw mounted for rotation about a pivot point, the jaw rotatable toward and away from a log feed axis along which pass logs to be clamped by the jaw; a brace mounted for translation adjacent to the jaw; and an actuation member movable between a first position and a second position, the actuation member coupled to the jaw and capable of pivoting the jaw about the pivot point with movement of the actuation member, the jaw having a tightened position with respect to the brace corresponding to the actuation member in its first position and in which the jaw is located a distance from the axis, and a loosened position with respect to the brace corresponding to the actuation member in its second position and in which the jaw is located a larger distance from the axis.

2. The log saw clamp as claimed in claim 1, wherein the actuation member is movable along a substantially linear path.

3. The log saw clamp as claimed in claim 1, wherein the brace is spring loaded for resiliently biasing the brace in a range of translational positions.

4. The log saw clamp as claimed in claim 1, wherein the brace is coupled to the actuation member for translational movement therewith.

5. The log saw clamp as claimed in claim 4, further comprising at least one clamp rod coupling the brace to the actuation member.

6. The log saw clamp as claimed in claim 1, wherein the brace has a concave surface facing logs in the log saw clamp.

7. The log saw clamp as claimed in claim 1, wherein the jaw has a concave surface facing logs in the log saw clamp

8. The log saw clamp as claimed in claim 1, wherein the jaw is adjustable through a range of jaw positions between and including the tightened position and the loosened position via movement of the actuation member through a range of actuation member positions between and including the first position and the second position.

9. The log saw clamp as claimed in claim 1, wherein the jaw has a jaw mount releasably coupled to a jaw member, the jaw mount having a surface for contacting logs in the clamp and the jaw member being coupled to the actuation member for rotational movement of the jaw by the actuation member.

10. The log saw clamp as claimed in claim 9, wherein the clamp has at least two different jaw members for clamping logs of different types, the at least two different jaw members releasably coupled to the jaw mount.

11. The log saw clamp as claimed in claim 1 , wherein the actuation member has a cam surface and wherein the jaw has a cam surface, the actuation member being coupled to the jaw via riding contact of the jaw cam surface against the actuation member cam surface.

12. The log saw clamp as claimed in claim 11, wherein the cam surface of the jaw is a pin extending from the jaw.

13. The log saw clamp as claimed in claim 12, wherein the cam surface of the actuation member is an elongated aperture defined in the actuation member and into which the pin is received and is slidable.

14. The log saw clamp as claimed in claim 11, wherein the jaw has a range of rotational positions with respect to the actuation member between and including the tightened position and the loosened position, the rotational positions of the jaw corresponding to different relative positions of the jaw cam surface against the actuation member cam surface.

15. The log saw clamp as claimed in claim 11, wherein the jaw is adjustable via movement and camming of the actuation member against the jaw.

16. A method for clamping a log to be cut by a log saw, the method comprising the steps of: providing a jaw mounted for pivotal movement about a pivot point; providing a brace mounted for translational movement with respect to the jaw; providing an actuation member coupled to the jaw; moving the actuation member along an actuation path in a first direction; pivoting the jaw about the pivot point toward a log path in response to movement of the actuation member along the actuation path; translating the brace toward the log path; moving a log to a position within the log clamp; and cutting a log with the log saw.

17. The method as claimed in claim 16, wherein the actuation path is substantially linear.

18. The method as claimed in claim 16, wherein the brace is coupled to the actuation member and wherein movement of the actuation member along the actuation path generates translational movement of the brace.

19. The method as claimed in claim 18, wherein the actuation member and the brace translate in the same substantially linear direction.

20. The method as claimed in claim 16, wherein the step of pivoting the jaw and the step of translating the brace occur substantially simultaneously with the step of moving the actuation member along the actuation path.

21. The method as claimed in claim 16, wherein the steps of cutting the log and the steps of pivoting the jaw and translating the brace occur at substantially the same time.

22. The method as claimed in claim 16, further comprising the steps of: moving the actuation member along the actuation path in a second direction opposite to the first direction; pivoting the jaw about the pivot point away from the log path in response to movement of the actuation member along the actuation path in the second direction; and translating the brace away from the log path.

23. The method as claimed in claim 16, wherein the step of pivoting the jaw in response to movement of the actuation member includes the step of camming a surface of the actuation member against a surface of the jaw to pivot the jaw about the pivot point.

24. The method as claimed in claim 23, wherein the surface of the actuation member is a surface of a pin coupled to the actuation member.

25. The method as claimed in claim 24, wherein the surface of the jaw is a surface of an aperture defined in the jaw, the pin being received and slidable within the aperture.

26. The method as claimed in claim 16, wherein the jaw has a jaw mount and a jaw member coupled to the mount, the method further comprising the steps of: removing the jaw member from the jaw mount; and coupling a different jaw member to the jaw mount.

27. A log saw clamp for clamping logs, comprising: an actuation member mounted for movement through a range of positions bounded by a first position and a second position; a brace; at least one clamp rod coupling the brace to the actuation member; and at least one jaw mounted for rotation about a pivot point, the jaw coupled to the actuation member for substantially simultaneous rotational movement of the jaw via translational movement of the actuation member.

28. The log saw clamp as claimed in claim 27, wherein the brace is mounted for translation.

29. The log saw clamp as claimed in claim 28, wherein the brace is mounted for translation with the actuation member.

30. The log saw clamp as claimed in claim 27, wherein the brace is spring-loaded.

31. The log saw clamp as claimed in claim 27, wherein the brace has a curved surface facing logs received in the clamp.

32. The log saw clamp as claimed in claim 31 , wherein the at least one jaw has a curved surface facing logs received in the clamp.

33. The log saw clamp as claimed in claim 27, wherein the at least one jaw has a curved surface facing logs received in the clamp.

34. The log saw clamp as claimed in claim 27, wherein the at least one jaw has a position with respect to logs received in the clamp, the position of the at least one jaw being adjustable by movement of the actuation member.

35. The log saw clamp as claimed in claim 27, wherein the at least one jaw has a jaw member releasably coupled to the jaw member and replaceable with jaw members having different dimensions.

36. The log saw clamp as claimed in claim 27, wherein the at least one jaw is coupled for rotational movement by the actuation member via a cam and pin set.

37. The log saw clamp as claimed in claim 36, wherein the cam of the cam and pin set is a surface at least partly defining an aperture in the at least one jaw.

38. The log saw clamp as claimed in claim 27, wherein the at least one clamp rod is coupled to the brace and to the actuation member for substantially translational movement.

39. The log saw clamp as claimed in claim 27, wherein the brace is coupled to the at least one clamp rod for substantially translational movement therewith.

40. A method for adjusting a log saw clamp for clamping a log, the method comprising the steps of: rotating a jaw toward the log saw clamp; translating a brace toward the log substantially simultaneously with the step of rotating the jaw; and cutting the log.

41. The method as claimed in claim 40, further comprising the step of translating an actuation member to rotate the jaw.

42. The method as claimed in claim 41, wherein the step of rotating the jaw includes camming a surface of the actuation member against a surface of the jaw.

43. The method as claimed in claim 40, further comprising the steps of: removing at least a portion of the jaw; and replacing the at least a portion of the jaw with one having different dimensions.

44. A log saw clamp for clamping logs in a log receiving area having an axis along which logs travel, the log saw comprising: a first clamp member mounted for substantially radial movement with respect to the axis; and a second clamp member mounted for movement along a path towards and away from the axis, the path having a radial component and a tangential component with respect to the axis.

45. The log saw clamp as claimed in claim 44, further comprising a third clamp member mounted for movement along a second path toward and away from the axis, the path having a radial component and a tangential component with respect to the axis.

46. The log saw clamp as claimed in claim 45, wherein the paths of the second and third clamp are arcuate and converge toward the axis.

47. The log saw clamp as claimed in claim 44, wherein the first clamp member is a brace mounted for translation beside the log receiving area.

48. The log saw clamp as claimed in claim 44, wherein the second clamp member is a jaw mounted for rotation about a pivot point beside the log receiving area.

49. The log saw clamp as claimed in claim 47, wherein the second clamp member is a jaw mounted for rotation about a pivot point beside the log receiving area.

50. The log saw clamp as claimed in claim 44, wherein the first clamp member and the second clamp member are coupled to an actuation member for movement thereby.

51. The log saw clamp as claimed in claim 50, wherein the second clamp member is movable by camming contact of the actuation member against the second clamp member.

52. A method for adjusting a log saw clamp, comprising the steps of: providing a first clamp member and a second clamp member at least partially surrounding a log receiving area; moving the first clamp member substantially radial path of motion with respect to the log receiving area; and moving the second clamp member through a path of motion having a radial component and a tangential component with respect to the log receiving area.

53. The method as claimed in claim 52, wherein the steps of moving the first clamp member and moving the second clamp member occur substantially simultaneously.

54. The method as claimed in claim 52, wherein the log receiving area has a size at least partially defined by positions of the first and second clamp members, and wherein the size of the log receiving area changes during movement of the first and second clamp members.

55. The method as claimed in claim 52, further comprising the step of moving a third clamp member through a path of motion having a radial component and a tangential component with respect to the log receiving area.

56. The method as claimed in claim 55, wherein the paths of motion of the second and third clamp members converge toward the log receiving area.

57. The method as claimed in claim 52, wherein the first clamp member is spring loaded.

58. The method as claimed in claim 52, further comprising the steps of: moving an actuation member coupled to the first and second clamp members; and camming the actuation member against the second clamp member to move the second clamp member through its path of motion.

59. The method as claimed in claim 58, wherein the step of moving the second clamp member through a path of motion includes the step of pivoting the second clamp member about a pivot point.