US3578044A

US3578044A - Carriage for sawing shake bolts into wedges

Info

Publication number: US3578044A
Authority: US
Inventors: Norman E Norlander; Robert A Knowles
Original assignee: Weyerhaeuser Co
Current assignee: Weyerhaeuser Co
Priority date: 1969-02-26
Filing date: 1969-02-26
Publication date: 1971-05-11
Anticipated expiration: 1988-05-11

Abstract

A shake bolt is supported on a carriage for movement relative to a cutting saw. The carriage has grasping rollers which engage the ends of the bolt and feed it into the plane of the saw. Each roller is driven by a stepped drive to provide alternate larger and smaller rotation step movements for the rollers on opposite ends of the bolt. While the roller at the first end rotates the larger rotation step, feeding the first end of the bolt a greater distance beyond the saw plane to produce a butt cut, the roller at the other end rotates a smaller rotation step, feeding the other end a lesser distance beyond the saw plane, to produce a tip cut. This cycle alternates with a second cycle wherein the roller at the first end rotates the smaller rotation step for a tip cut while the other roller rotates the larger step for a butt cut. The system for aligning the grasping rollers with the end surfaces of the bolts and the two-step drive system are disclosed in detail.

Description

United States Patent [72] Inventors Norman E. Norlander Longview;

Robert A. Knowles, Tacoma, Wash. 802,609

Feb. 26, 1969 May 11, 1971 Weyerhaeuser Company Tacoma, Wash.

[21 Appl. No. [22] Filed [45] Patented [73] Assignee [54] CARRIAGE FOR SAWING SHAKE BOLTS INTO 525,049 8/1894 Ireland 3,467,154 9/1969 Girard ABSTRACT: A shake bolt is supported on a carriage for movement relative to a cutting saw. The carriage has grasping rollers which engage the ends of the bolt and feed it into the plane of the saw. Each roller is driven by a stepped drive to provide alternate larger and smaller rotation step movements for the rollers on opposite ends of the bolt. While the roller at the first end rotates the larger rotation step, feeding the first end of the bolt a greater distance beyond the saw plane to produce a butt cut, the roller at the other end rotates a smaller rotation step, feeding the other end a lesser distance beyond the saw plane, to produce a tip cut. This cycle alternates with a second cycle wherein the roller at the first end rotates the smaller rotation step for a tip out while the other roller rotates the larger step for a butt cut. The system for aligning the grasping rollers with the end surfaces of the bolts and the twostep drive system are disclosed in detail.

CARRIAGE FOR SAWING SHAKE BOLTS INTO WEDGES CROSS-REFERENCE TO RELATED APPLICATIONS BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to processing equipment and more particularly to an apparatus for producing wedge-shaped articles such as tapered wood products.

2. Description of the Prior Art Because of their aesthetic features and excellent utilitarian characteristics, such as good weathering and long life, wooden shakes and particularly the handsome rough split shakes produced from western red cedar are in great demand as roof and sidewall exterior covering materials. In recent times a number of factors have made it difficult to either meet the increasing demand for such shakes or to produce the shakes at a low enough cost to be competitive with other exterior covering materials. One principal factor is that there is a diminishing supply of shake quality cedar logs and therefore the producer is most interested in obtaining the maximum yield out of a given volume of such wood.-ther factors include the general use of relatively slow production'processes involving manual bolt splitting.

Several devices and techniques have been developed for producing tapered shake wedges or shakeblanks which can be resawn into wedges. In the patent to Faber U.S. Pat. No. 2,145,568 there is disclosed a carriage for supporting the large wood bolts from which are produced the tapered thin wooden wedges which are referred to as shingles because of their sawn faces and relative thinness. The bolts are initially positioned with one endportion of the boltextendinga greater distance into the plane of the saw than the other end portion. As the carriage is reciprocated past the saw, a tapered cutis made and for the next pass the alternate end of the bolt is positioned a greater distance into the plane of the saw so that the thicker portion of the tapered cut can be taken from the other end of the bolt. This device is rather slow in its production of tapered products and it requires a relatively thick saw with the teeth of the saw thicker than the body of the saw to eliminate rubbing friction against the body of the saw from the side'of the'bolt after it has passed through the saw. This machine is limited to the utilization of a single pass which means that when the carriage is reciprocated back from a sawing operation, no cutting takes place.

In the patent to Barnes et al. U.S. Pat. No. 2,789,596 tapered shakes are cut from bolt 44 as the bolt-supporting jig projects a portion of the bolt into the path of .a reciprocating saw. As the saw moves in one direction, the bolt is aligned against one of two angled guides 36. Then,.after the sawpass is made in one direction, the bolt is pushed against the opposite angled guide to position the remaining portion of the bolt at an opposite angle. When the saw is returned in the opposite direction, the tapered wedge is produced such as shown in FIG. 4 of that patent. While this apparatus provides a doublepass production system, it requires a great deal of manual effort to alternate the position of the bolt from aligning contact with the opposite angled guides. There is no provision for accommodating uneven sides of the bolt material.

In FIG. 1 of the patent to Stark U.S. Pat. No. 3,079,96] the traditional hand-splitting method for producing generally rectangular shake blanks from a bolt is shown utilizing'a knifeedged froe which is wedged into the end of the bolt causing the blank to split away from the bolt along the grain line to result in a natural split surface on both major faces of the :blank. The blank is then positioned in the resawing apparatus of the Stark patent for a canted cut resulting in two tapered shakes having sawn backs and naturally split exposed faces.

A much more elaborate apparatus for producing partially split, partially sawn shake boards isdisclosed in the patent to FergusonUS. Pat. No. 3,396,764.

OBJECTS AND SUMMARY OF INVENTION From the foregoing review of prior used systems for producing tapered articles, it is clear that there is a need for an improved system. For this reason it is the principal object of the instant invention to provide a generally improved, automaticallyoperated apparatus for accurately positioning and automatically feeding a wood bolt into the plane of a severing means to produce uniform tapered wedges.

Another object of the instant invention is to provide an apparatus for firmly grasping the major surface of the end portions of a bolt while feeding the bolt into the plane of a severing means which cuts the bolt in opposite directions.

A still further object of the instant invention is to provide, in a bolt-feeding apparatus, a step drive system which causes the feed rollers to'alternate from a large arc rotation to a small arc rotation to produce butt and tip cuts, respectively, as the bolt is fed a greater or lesser amount beyond the plane of the severing means.

A further aim of this invention is the provision, in'a shake manufacturing system, of a generallyimproved apparatus for producing tapered wedges of uniform dimensions, in which apparatus there .is a provision for easily, adjusting the actual dimensions of the thicker butt end and thinner tip end of the be rotated on the carriage supportand the tapered cuts made from the opposite side of the bolt when a knot or other defective portion of the bolt has been reached during-its feeding from its initial position.

In accordance with the present invention a bolt-supporting carriage is mounted for reciprocable movement relative to the severing means in the form of a double-edge band saw. The forward end edge of the bolt is grasped by one feed roller and the forward endedge of the other end of the bolt is grasped by another feed roller. A two-step drive system is connected to each of the rollers so that each roller can be alternately rotated in a large arc and then a small arc to project its end of the bolt a greater or lesser amount into the plane of the saw. While one roller is rotated a larger arc step, the other roller is rotated the smaller'arc step to yield a tapered cut producing a wedge-shaped article. The feed rollers are pivotally mounted so that they can be articulated against the end surface of the bolt so that the maximum contact between the roller and the end surface of the bolt is achieved, regardless of the irregularities in the end surface of the bolt. The two-step drive system is adjustable to vary 'the dimensions of the thicker and-thinner ends of the produced wedge as well as to vary the relationship between the thick and thin ends of the wedge produced. The double-edged saw provides a cutting action in both-directions that the carriage reciprocates.

These and other features and advantages of the invention will become more clearly apparent from the following detailed description thereof, which is'to be read with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 isa side elevation view illustrating the forward side of the improved apparatus made in accordance with the present invention with the shake bolt-supporting carriage located in its second position;

FIG. 2 is a top plan view of the improved apparatus illustrating the first position of the carriage withthe bolt feeding rollers in their open condition;

FIG. 3 is an end elevation view of the improved apparatus made in accordance with the present invention;

FIG. 4 is an isometric view, isolating the major components of the improved apparatus to illustrate the position of the shake bolt as it moves in a first direction from the first position of the carriage toward the second position of the carriage;

FIGS. 5 and 6 are side elevation views of the bolt-supporting portion of the improved apparatus illustrating the manner in which the feed rollers operate to grasp the ends of the bolt; and

FIG. 7 and 8 are top plan views of the bolt-feeding portion of the improved apparatus illustrating the manner in which the step drive system produces wedge-shaped articles.

DESCRIPTION OF THE PREFERRED EMBODIMENT Before a more detailed explanation of each of the operating systems is made, general reference to FIGS. I to 3 provides a basic understanding of the arrangement of the components of the improved shake bolt-cutting apparatus. A support structure 12 is positioned adjacent to a severing means 5 in the form of a band saw. The carriage assembly supports the shake bolt 60 between feed rollers and 44 and reciprocates along the forward and

rear guide rails

17 and 118. The bolt 60 is fed by

rollers

30 and 44 into the severing plane 9 to be cut by either the first cutting edge 6 or the second cutting edge 7 of the saw 5.

In more detail and with reference to FIGS. I to 3, support structure I2 is made up of a number of vertical members 13, horizontal members 14, and cross-bracing members 15, all providing adequate support and alignment for horizontally extending forward guide rail 17 and rear guide rail 18. Carriage assembly 20 is supported by forward bearing pads 21 and rear bearing pads 22 which slide along on the upper surfaces of both guide rails 17 and I8 as the carriage assembly 20 is reciprocated from its first position 56, as shown in FIG. 2, to its second position 58, as shown in FIG. I.

Carriage assembly 20 is composed of horizontal frame members 24, vertical frame members 25, and cross brace members 26. As shown in FIG. 2, a swing arm assembly is positioned in its open condition whereby second feed roller 44, supported on swing arm frame 41, is displaced its greatest distance from first feed roller 30 supported on the nonswinging portion of the carriage assembly 20. Swing arm positioning motor 42 is used to position swing arm frame 41 and second feed roller 44 as the swing arm assembly 40 is pivoted about arm pivot 43 from its open position shown in FIG. 2 to its closed position as shown in FIG. 1, whereas second feed roller 44 is positioned closer to first feed roller 30. Bolt 60 is supported on carriage assembly 20 by means of bolt skid rails 28.

Carriage 20 is reciprocated along rails 17 and 18 by means of a carriage drive system which includes a hydraulic or pneumatic motor cylinder 51 having a piston rod 52 secured at one end to rod retainer 53 forming a portion of carriage assembly 20 and at the other end cylinder 51 is secured to support structure 12 by means of cylinder support 54. As shown in FIG. 1, carriage assembly 20 is located in its second position 58 as piston rod 52 is retracted into cylinder 51. As shown in FIG. 2, carriage 20 is located in its first position 56 as piston rod 52 is extended outwardly from cylinder 51. To move car riage assembly 20 in a first direction, as shown by arrow 57, piston rod 52 is retracted into cylinder 51 to move carriage assembly 20 in a second direction, as shown by arrow 59, piston rod 52 is extended out from cylinder 51. Of course, any number of other drive systems could be used to move carriage 20 relative to saw 5.

It has been difficult in the past to accurately hold a shake bolt in a desired position relative to the cutting plane during a sawing operation because the relative movement between the bolt and saw tends to twist the bolt 60. Further, the ends of bolt 60, first end 63 and second end 64, do not generally present parallel even surfaces and grasping lugs often fail to firmly hold bolt 60 because too few portions of the bolt ends 63, 64 are in firm contact with the lugs. To provide the best grasping of the bolt 60, a grasping system has been developed which includes first feed roller 30 and second feed roller44. Grasping rings 31 having a gear tooth configuration are mounted along the length of first feed roller 30 and similar grasping rings 45 are mounted along the length of second feed roller 44 to cut into and thereby firmly contact the first and second ends 63 and 64 of bolt 60 as swing arm assembly 40 is moved from the open condition shown in FIG. 2 to the closed condition shown in FIG. I. As shown in FIG. I, roller pivot and

gearboxes

33 and 46 are mounted at the lower ends of first feed roller 30 and second feed roller 44, respectively. First feed roller 30 is secured to roller pivot 33 in a manner which permits it to pivot about roller pivot 33. In a similar manner second feed roller 44 pivots about roller pivot 46. To control the extent of pivot of first feed roller 30 about roller pivot 33, the upper end of feed roller 30 is fastened through motor support post 35 to first balance pneumatic motor 34 which is connected to vertical frame member 25 of carriage assembly 20 through pivot connector 36. Through the movement of swing arm assembly 40, second feed roller 44 moves laterally about arm pivot 43 due to the action of swing armpositioning motor 42. In addition, second feed roller 44 is pivoted about roller pivot 46 through the action of second balance pneumatic motor 47 which is secured to the upper end of motor support post 48 to which second feed roller 44 is also secured. Second balance pneumatic motor 47 is pivotally attached to the vertical portion of swing arm frame 41 through pivot connector 49.

In schematic form, FIGS. 5 and 6 illustrate the manner in which the uneven and nonparallel ends 63 and 64 of bolt 60 are firmly grasped by means of first and

second feed rollers

30 and 44. As shown in FIG. 2, once carriage assembly 20 is in its first position 56 and swing arm assembly 40 is moved outwardly to its open position, bolt 60 is pushed along bolt skid rails 28 toward the forward side of the carriage assembly 20. Bolt 60 is then grasped between first and

second feed rollers

30 and 44, as swing arm-positioning motor 42 is reversed, retracting its piston rod and thereby rotating swing arm assembly 40 about arm pivot 43 so that second feed roller 44 is brought toward first feed roller 30 as shown in FIG. 5. The forces applied by first and second balance motors 34 and 47 are exactly equal to one another and to the forces applied to the

roller pivot boxes

33 and 46 by swing arm-positioning motor 42. The force Ful; representative of the force applied to the upper left end of first feed roller 30, is equal to and in the same direction that the force Fll that is applied to the lower left portion of first feed roller 30. These forces are opposed at bolt 60 by force Fbl at the first point 65 on first end 63 of bolt 60 to be engaged by the grasping rings 31. Force Fbl is equal to the sum of the forces Fu! and F11 applied by first feed roller 30. Since there is a greater length of moment arm Lll at the lower left between left contact point 65 and lower left force F11 than the moment arm Lul at the upper left from the left point 65 and the force Ful; feed roller 30 is pivoted in a counterclockwise direction about left point 65 until a major portion of the first end 63 is engaged by a number of the grasping rings 31 of first feed roller 30, as shown in FIG. 6. This counterclockwise movement of feed roller 30 occurs by means of V the retraction of first balance pneumatic motor 34 permitting a counterclockwise movement of motor support post 35 and first feed roller 30 about roller pivot block 33.

In a similar manner, the forces applied to the upper and lower ends of second feed roller 44, Fur and Flr; ur respectively, are equal to one another and are opposed by the force Fbr at right-hand point 66 of the second end 64 of bolt 60 as it makes contact with one of the grasping rings 45 of second feed roller 44. In this situation, however, the length of the moment arm Lur from contact 66 to the upper right-hand end of second feed roller 44 is shorter than the moment arm Llr extending downwardly from contact point 66 to the point where the lower right-hand force Flr is applied to second feed roller I 44. This imbalance of moment arms causes the clockwise rotation of second feed roller 44 about right-hand point 66 until a number of the grasping rings 45 make firm contact with second end 64 of bolt 60. This change in position is shown by comparison of FIGS. 5 and 6. The change in this situation is caused by the further inward movement of roller pivot 46 as swing arm-positioning motor 42 is retracted brining at least the lower right-hand portion of second feed roller 44 closer to first feed roller 30 and the combined motion of perhaps a retraction of second balance motor 47. It could be stated that there is an articulation of

feed rollers

30 and 44 about their first contact points 65, 66 with the

ends

63, 64 of bolt 60 until a major portion of the grasping

rings

31, 45 on

feed rollers

30, 44 has made a firm contact with a major portion of the end faces 63 and 64 of bolt 60.

The center of thespan of

feed rollers

30 and 44 between'the point where the balance motors 34 and 47 apply their forces and the roller pivots 33 and 46 can be, by design, positioned at the midpoint of the most commonly processed bolts. ln this particular situation since the saw 5 makes a downward cut into the bolt 60, there is little tendency for the bolt to be picked up from the supporting skid rails 28 even though the forces applied to the

ends

63, 64 of bolt 60 might tend to be in a somewhat upward direction, such as shown in FIG. 6. ln-

cidentally, it is considered good practice to put any bark portion of the bolt against the skids 28 so that if any rocks and other foreign matter are contained in the bark, they will be pushed downwardly by the downward movement of saw 5 rather than dragged through the material as would be the case if the bark portion were located at the upper position.

Once bolt 60 has been firmly grasped between first and

second feed rollers

30 and 44 in a condition. such as shown in FIG. 6, bolt 60 is projected through the severing plane'9 a sufficient distance and at a proper angle to provide the desired tapered cut. For this purpose and as shown somewhat schematically in FIGS. 4, 7 and 8, feed

rollers

30 and 44 are rotated about their axis by means of a stepped drive system generally identified at 84.

To rotate first feed roller 30, a first drive shaft 85 extends from the roller pivot and 90 gearbox 33 into a first clutchbrake assembly 87. Extending from the other end of clutch brake 87 is a drive crank 88 having a crank am 89 and a crank connector 90 for connecting the crank am 89 with the first motion-producing elements 91. The clutch-brake assembly 87 is a commercially available item which is preferably electrically operated in a manner which permits the rotation of crank arm 89 to be selectively transferred in the form of rotation to first drive shaft 85. The brake portion of the assembly 87 selectively holds first drive shaft 85 in a fixed position even though the crank arm 89 might be rotated.

First motion-producing elements 91 include a major motion drive rod 92 extendable from a major motion cylinder motor 93 and a minor motion cylinder motor 94 having extendable from it a minor motion drive rod 95 which is connected to the carriage assembly through pivot connector 97. Through crank arm connector 90, first motion-producing elements 91 rotate crank arm 89 and drive crank 88 in two modes. The first mode may be considered the larger arc mode and this is the result of the expansion of the major motion drive rod 92 to its greatest extension out of major motion motor cylinder 93. This expansion produces in drive crank 88 a rotation of the greatest number of degrees of are. A second mode, termed a minor arc of rotation, results from the extension of the minor motion drive rod 95 to its maximum position out from minor motion motor cylinder 94. Although it is not necessary to the operation of this particular system, it would be also possible to get an even greater rotation of crank 88 by'the maximum extension of both drive

rods

92 and 95 from their

respective cylinder motors

93 and 95 at the same time. For the purposes of this particular system, however, it is adequate that there are two different motions of different are sizes.

Through the connection of clutch brake 87 and first drive shaft 85, first feed roller 30 is then rotated a greater or lesser arc, depending upon whether the major or minor

motionproducing elements

93 or 94 are operated. Once drive

rods

92 or 95 have been extended, the clutch between drive shaft and crank 88 is disengaged and the brake for drive shaft 85 is engaged to permit drive rod 92 or to be retracted into its

respective cylinder

93 or 94, without causing a counterrotation of the drive shaft 85. in a manner of speaking, there is a ratchet-type drive provided for first drive shaft 85 which results in a stepped rotation for first feed roller 30.

The identical sequence and operating functions are performed by the corresponding stepped drive components for the second feed roller 44. These components include second drive shaft 103, second clutch-brake assembly 106, second crank 115, second crank arm 117, second crank connector 118, and second motion-producing elements /The motion-producing elements include major motion drive rod 121 extendable from major motion drive motor cylinder 122 and minor motion drive rod 124 extendable from minor motion motor cylinder 123. Second motion-producing elements 120 are connected to the swing arm assembly 40 of carriage 20 through pivot connector 126.

As shown in FIG. 4, crank arm 117 is illustrated as having a threaded section whereby the position of the crank connector 118 can be changed relative to the axis of the crank shaft 115. Such a change in the effective arm changes the relative relationship between the amount of rotation provided by the stepped drive 120 which results in a change in the relationship between the thinner and thicker ends of the wedges produced by this equipment. ln a similar manner shims 98 may be inserted between the

pivot connectors

97 or 126 and the carriage assembly 20 or swinging arm assembly 40 to change the effective length of the first and second motion-producing

elements

91 and 120. This change in effective length results in a change in the actual amount of rotation provided by the stepped drive system 84, but does not change the relationship between the smaller and larger arcs produced. Thus it is possible for the wedged article producer to change the relationship between the thick and the thin wedged by changing the effective crank arm length to change the actual thickness of 'the thick and thin ends of the wedged articles by use of shims or other similar means for changing the effective length of the first and second motion-producing

means

91 and 120.

Before the operation of the improved apparatus 1 is described, it is noted that those skilled in the art may use electrical and fluid pressure control systems of a wide variety design and involving the use of conventional and even yet to be developed position sensing switches and similar components to produce the sequence of operation related herein. Adequate systems are well known and need not be described in detail since they form no part of the instant invention.

ln operation, when carriage drive system 50 is cycled, carriage assembly 20 is reciprocated back and forth between the first and second positions 56 and 58 along the forward and rear guide rails 17 and 18 of the support structure 12. With reference to FIG. 7, it is noted that bolt 60 is projectedwith its first end 63 positioned a greater distance beyond the severing plane 9 than is its second end'64. Thus, a carriage assembly 20 moves in first direction 57 relative to saw 5, first cutting edge 6 produces the first cut 70 in bolt 60 yielding a single shake 71. 1t should be noted that as bolt 60 is initially positioned within improved apparatus 1, its front face 61 is a naturally split face as is its rear face 62. Thus, the single shake 71 produced by the first cut 70 has a naturally split face 61 and a sawn face resulting from first cut 70.

The positioning of bolt 60 shown in FIG. 7, results from the cycling of the stepped drive system 84 in what is referred to as a jogging operation whereby both the first and second

motionproducing elements

91 and 120 are cycled at the same time to produce the same amount of arc rotation for

feed rollers

30 and 44. This jogging can continue until the operator feels that the bolt is approximately in the right position. At this time either the first motion-producing elements 91 are cycled or the second motion-producing elements 120 are selectively cycled to finally inch the front face 61 of the bolt 60 into the desired position for making the first cut 70. As part of the skill of the operator it is his job to see to it that the cuts are made in such a manner that the natural splitting grain of the bolt is positioned at the middle point of the thicker butt end and the thinner tip end of the wedges produced. Thus, in a later operation when a portion of the wedge product is resawn generally from the tip end toward the butt end, the balance of the severance of the wedge article into two shakes produces two shakes having partial split faces and the butt end of these shakes is approximately equal.

As shown in FIG. 7 the first cut 70 is made through the selective cycling of the

feed rollers

30 and 44 and the movement of the carriage 20 from its first position 56 in a first direction 57 toward its second position 58 as piston rod 52 of carriage drive system 50 is retracted into carriage motor cylinder 51. Before the reciprocal motion is started, stepped drive system 84 is automatically cycled so that a greater portion of second bolt end 64 is projected into severing plane 9 than first end 63. This results from the greater are rotation of second feed roller 44 as compared to the lesser arc of rotation of first feed roller 30. With reference to FIG. 8, it is noted that second major motion drive rod 121 is extended outwardly from second major motion drive motor cylinder 122 to cause crank arm 117 to move through a major are. This major arc movement is transmitted through second drive clutch-brake assembly 106 to second drive shaft 103, which in turn through the second roller pivot and 90 gearbox 46 positioned at the lower end of second feed roller 44 causes the major arc rotation of second feed roller 44. At the same time, first minor motion drive rod 95 is extended from first minor motion motor cylinder 94 of the first motion-producing elements 91 to thereby move first crank arm 89 and drive crank 88 a smaller arc of rotation. This smaller arc rotation is transmitted through first clutch-brake assembly 87 to first drive shaft 85. The rotation of drive shaft 85 is transferred through roller pivot and 90 gearbox 33 to the lower end of first feed roller 30 resulting in its rotation to extend first end 63 of bolt 60 a smaller amount of distance beyond the severing plane 9. As carriage drive motor cylinder 51 reverses its operation extending piston rod 52, carriage assembly 20 is moved from its second position 58 to its first position 56 in a second direction 59 so that the second cut 72 can be made as second cutting edge 7 of saw is drawn through bolt 60. This produces a first wedge 73 having two sawn faces, the first face produced by first cut 70 and the second face produced by second cut 72. The grain plane 76, providing the natural splitting effect, run midway through the tip end 75 to a midpoint in the butt end From this point on the operation is repeated with the alternate cycling of

feed rollers

30 and 44 in a greater or lesser arc as required to provide the alternate butt and tip ends of the wedges at each end of the bolt 60. If partway through a bolt 60 a large knot 80 is discovered, the operator can merely turn the bolt around so that rear face 62 of bolt 60 is positioned toward the front side of the carriage assembly 20 and the machine can be cycled to provide a number of wedge cuts leaving the knot portion alone, since it would be waste in any case. The only purpose for doing this is to reduce the amount of damage caused to the saw by having to cut through the knot.

It is therefore seen that we have developed a generally improved apparatus for producing wedge cuts which utilizes an improved system for grasping the ends of the bolt to be cut so that it can be cut in either direction as the carriage is reciprocated past the double-edged saw. This apparatus also includes a stepped drive system which alternately and automatically changes the amount that the end of the bolt is projected beyond the plane of the saw so that alternate tip and butt cuts can be made as the bolt is reciprocated along with the carriage relative to the doubleedged saw. The relative thickness between the tip and butt ends of the wedged articles produced can be varied and the relationship between the thickness of the butt and the thickness of the tip of the articles can also be varied.

We claim:

1. An apparatus for moving a workpiece relative to a severing means comprising in combination:

carriage means including grasping means for firmly holding opposite ends of said workpiece and feeding said workpiece relative to the cutting plane of said severing means;

carriage drive means for moving said carriage relative to said severing means;

two-step drive means operatively connected to said grasping means for sequentially feeding one end of said workpiece a greater and then a lesser distance beyond said cutting plane while feeding the other end of said workpiece a lesser and then a greater distance beyond said cutting plane as said carriage drive means reciprocates said carriage relative to said severing;

said grasping means includes spaced-apart first and second feed rollers each having surfaces for engaging said workpiece ends;

said twostep drive means includes first and second drive shaft means operatively connected to said first and second feed roller means, respectively, for transferring rotational movement of said shaft means into rotational movement of said feed rollers for moving said first and second ends of said workpiece toward said severing plane;

said two-step drive means also includes first and second crank arms operatively connected to said first and second drive shafts for applying rotational movement thereto and first and second motion-producing elements connected to said crank arm for applying a rotational movement thereto;

each of said motion-producing elements being operative in at least two modes, a minor mode for applying a minor arc of rotation to said crank arm and a major mode for applying a major arc of rotation to said crank arm;

each of said motion-producing elements includes a major and minor extendable motor means;

said major motor means when operated extends a greater amount for said major mode than said minor motor means when operated extends for said minor mode.

2. An apparatus for moving a workpiece relative to a severing means comprising in combination:

carriage drive means for moving said carriage relative to said severing means;

said grasping means includes spaced-apart apart first and second feed rollers each having grasping rings for engaging said workpiece ends;

said carriage means also including a nonswinging portion for supporting said first feed roller, a swing arm assembly pivotally mounted on said nonswinging portion for supporting said second feed roller and a swing arm-positioning means for positioning said swing arm and second feed roller relative to said first feed roller for selectively grasping and releasing said workpiece;

said feed roller means are pivotally supported at one end thereof by roller pivot means for rotation about an axis normal to said severing plane with the other end thereof supported by balance force application means;

said swing arm-positioning means being operatively connected to said roller pivot means for applying a grasping force to said one end of said roller means;

the force applied to said other end of said feed roller means by said balance force means being equal to and in the same direction that said grasping force is applied to said roller pivot means by said swing arm-positioning means when said workpiece is positioned between said first and second feed rollers.

ggggg UNITED STATES PATENT omen CERTIFICATE OF CORRECTION Patent No. 3,578,044 Dated May 11, 1971 Inventor(s) NORMAN E. NORLANDER and ROBERT A. KNOWLES It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In column 4, line 66, "ur respective-" should read -respectivein column 5, line 6, "brining" sho'uld read --bringing--;

in column 6, line 38, "thin wedged" should read --thin articles wedged-;

in column 6, line 39, "length" should read --length and---.

Signed and sealed this 2L .th day of August 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, J'R. Attesting Officer Commissioner of Patents

Claims

1. An apparatus for moving a workpiece relative to a severing means comprising in combination: carriage means including grasping means for firmly holding opposite ends of said workpiece and feeding said workpiece relative to the cutting plane of said severing means; carriage drive means for moving said carriage relative to said severing means; two-step drive means operatively connected to said grasping means for sequentially feeding one End of said workpiece a greater and then a lesser distance beyond said cutting plane while feeding the other end of said workpiece a lesser and then a greater distance beyond said cutting plane as said carriage drive means reciprocates said carriage relative to said severing; saId grasping means includes spaced-apart first and second feed rollers each having surfaces for engaging said workpiece ends; said two-step drive means includes first and second drive shaft means operatively connected to said first and second feed roller means, respectively, for transferring rotational movement of said shaft means into rotational movement of said feed rollers for moving said first and second ends of said workpiece toward said severing plane; said two-step drive means also includes first and second crank arms operatively connected to said first and second drive shafts for applying rotational movement thereto and first and second motion-producing elements connected to said crank arm for applying a rotational movement thereto; each of said motion-producing elements being operative in at least two modes, a minor mode for applying a minor arc of rotation to said crank arm and a major mode for applying a major arc of rotation to said crank arm; each of said motion-producing elements includes a major and minor extendable motor means; said major motor means when operated extends a greater amount for said major mode than said minor motor means when operated extends for said minor mode.

2. An apparatus for moving a workpiece relative to a severing means comprising in combination: carriage means including grasping means for firmly holding opposite ends of said workpiece and feeding said workpiece relative to the cutting plane of said severing means; carriage drive means for moving said carriage relative to said severing means; two-step drive means operatively connected to said grasping means for sequentially feeding one end of said workpiece a greater and then a lesser distance beyond said cutting plane while feeding the other end of said workpiece a lesser and then a greater distance beyond said cutting plane as said carriage drive means reciprocates said carriage relative to said severing; said grasping means includes spaced-apart apart first and second feed rollers each having grasping rings for engaging said workpiece ends; said carriage means also including a nonswinging portion for supporting said first feed roller, a swing arm assembly pivotally mounted on said nonswinging portion for supporting said second feed roller and a swing arm-positioning means for positioning said swing arm and second feed roller relative to said first feed roller for selectively grasping and releasing said workpiece; said feed roller means are pivotally supported at one end thereof by roller pivot means for rotation about an axis normal to said severing plane with the other end thereof supported by balance force application means; said swing arm-positioning means being operatively connected to said roller pivot means for applying a grasping force to saId one end of said roller means; the force applied to said other end of said feed roller means by said balance force means being equal to and in the same direction that said grasping force is applied to said roller pivot means by said swing arm-positioning means when said workpiece is positioned between said first and second feed rollers.