US2894545A - Scarfing machine - Google Patents

Description

R. E. WIRTH SCARFING MACHINE Jul 14, 1959 9 Sheets-Sheet 1 Filed Dec. 15, 1955 R m m V m Raymond 6 WI fh ATTORNEY July 14, 1959 R. E. WIRTH SCARFING MACHINE 9 Sheets-Sheet 3 Filed Dec. 15, 1955 M2 5 55 MM m ..r n I I I l l l l ll W/ a W 0 n d 1 M w w Z 1 m w 4 z 2 i 0 w 2 0 a Z2 Z 4 2 0 \\.Y Z 2 M m F July 14, 1959 R. E. WIRTH 2,894,545

7 SCARFING MACHINE Filed Dec; 15, 1955 9 Sheets-Sheet 4 I, I I "157- 'f' 429 A27 INVENTOR )7 6 245 Raymond L: "VI/#1 ,a/VHQ ATTORNEY July 14, 1959 R. E. WIRTH 2,894,545

- SCARFING MACHINE Filed Dec. 15, 1955 9 Sheets-Sheet 7 n 317 2391 24,; za" 313 3 20)L"--:i 9 -i-zza 'INVENTOR 3114 Raymond E Wl'rfh ATTORNEY July 14; 1959 R. E. WIRTH 2,894,545

7 v SCARFING MACHINE Filed Dec. 15; 1955 9 Sheets-Sheet 9 INVENTOR Pal mane fV/rf/z ATTORNEY States Patent SCARFING MACHINE Raymond E. Wirth, St. Paul, Minn., assignor to Rilco Laminated Products, Ramsey County, Minn., a corporation of Minnesota Application December 15, 1955, Serial No. 553,241

21 Claims. (Cl. 144-125) This invention relates to an improvement in method and apparatus for producing scarfed joints and deals par ticularly with an apparatus for scarfing the ends of boards suchas those used for making laminated beams and with the method of accomplishing this scarfing operation.

The need for a high speed scarfing machine has been widely recognized. In a technical bulletin 1069 published by the Forest Products Laboratories of Madison, Wisconsin, the need for a high speed scarfing apparatus is noted. This bulletin states there are no high speed machines on the market suitable for a low cost high volume production of glued end joints. It is a purpose of the present invention to fulfill this need.

Various types of scarfing machines have been produced. These machines normally include rotating cutters of some type which cut the board at a predetermined angle. Most such machines are extremely slow in operation and are not adaptable to varying conditions. For example, many such machines are capable of cutting boards of a predetermined thickness. In most instances, the angle of the scarf cannot be changed and cannot accommodate boards of varying thickness. Furthermore, with most such machines, it is necessary for the operator to go through a predetermined sequence of operations during the scarfing operation. The operator must first place each board in position to be scarfed and operate some type of holding mechanism to hold the board in place. He must then move the board relative to the rotating cutters in order to produce the tapered cut. The board must then be unclamped and removed, and the apparatus returned to its starting position. Such a procedure is time consuming and is subject to human error.

An object of the present invention resides in the provision of a scarfing machine which functions automatically to complete a scarfing operation once the cycle has been started. When the board is in place and operation is started, the apparatus automatically clamps the board to a movable table, tilts the table to produce a desired angle of cut, moves the table past the rotating cutters to produce the tapered end, ti'lts the table back into its normal horizonal position, unloads the scarfed board and returns the table to its starting location. As a result, considerable time is saved and the chance of following an improper sequence of operation is eliminated.

A feature of the present invention resides in the provision of a scarfing apparatus which cuts the board in a direction longitudinally of the grain. All scarfing machines in use at the present time out across the grain transversely in varying degree as well as longitudinally. It is the transverse cut of the knives that causes the damage which the present apparatus eliminates.

The primary purposes of the machine are several fold. One of the first purposes is to accurately machine a sloping scarf within allowable tolerances of laminating procedure and with resulting surface the best possible for producing maximum bond with adhesives and intimate contact of gluing surfaces. While somewhat a high standard to achieve, the structure has proven to produce this result.

A second purpose of the apparatus is to machine scarf surfaces with controlled removal of wood by cutting chips of uniform shape and size which feather out when the knife completes the cut, without the usual chip breaking and lifting action at the heavy end of the chip, such' as usually occurs in normal surfacing machines.

A third purpose of this invention is to machine scarf surfaces by cleanly cutting the wood fibres without crushing or tearing and in a direction parallel to the longitudinal axis of the board, without any disruption of wood fibres due to knives or cutters operating transversely or at an angle to the longitudinal axis of the board.

A fourth purpose of the present invention lies in the provision of an apparatus to machine scarf surfaces in one operating cycle by first a roughing cut and a final surfacing with a light cut and in the proper direction to prevent compressing or otherwise damaging the wood fibres.

A fifth object of this invention is to machine scarf surfaces without the necessity of first introducing fiber stress in the area to be cut by slight bending to facilitate holding the piece during the cutting operation.

A feature of the present invention resides in the fact that the length of the scarfed joint may be regulated. The angle of tilt of the table is variable and may be easily changed between cycles of operation. Once set, the table will tilt to the same extent during each cycle of operation until readjusted.

A further feature of the present invention lies in the fact that the apparatus automatically accommodates boards of various thickness. Within practical limits, the clamping mechanism will exert a predetermined equal pressure on each board scarfed, regardless of board thick .ness.

An added feature of the present invention lies in the' provision of automatically operable board-locating stops. These stops project above the table level to provide shoulder means against which the board is engaged to properly position the board for the scarfing cut. The stops auto-' matically retract once the board is clamped to the table, leaving the forward end of the board unobstructed during the scarfing operation. until after the board has been removed from the table, at which time they automatically project into board positioning position.

A feature of the present invention lim in the automatic tilting of the table during the actual cutting operation, and in returning the table to horizontal position at the completion of the cut. By this arrangement, the board may be positioned and Withdrawn while the table is horizontal.

Another advantage of the construction lies in the fact that the table is pivotally supported intermediate its ends. As the table is tilted, the forward edge elevates and the rear edge drops until the proper angle of tilt is provided. As a result, the scarf is cut in the elevated forward end of the board as the table moves forwardly. At the completion of the cutting operation, the forward end of the table lowers until the table is horizontal. lowers the board and table below the level of the cutters, so that the cutters are completely out of the vicinityof the table during the remainder of the cycle.

Still another feature of this invention lies inthe aris scarfed. Resiliently supported hold down members engage the board on both sides of the cutters as well as between the same, providing an effective control of the board as it is scarfed.

The control apparatus which provides automatic func- Patented July 14, 1959 The stops remain retracted This.

ass-gses c tioning of the various operating elements in proper sequence is also of importance in the present invention. The completion of each step of operation initiates the next subsequent step, eliminating the danger of error in omitting a step or following an improper sequence. With this control, the table cannot be tilted or moveduntil the board is clamped, and the cutting operation cannot occur unless the board is clamped, the table tilted and the board positioning stops retracted. Greater safety of operation is thus effected, as well as higher speed and simplicity of operation.

In planing and surfacing boards with rotating cutters, the cutting reels rotate in a direction opposite to the forward movement of the board being surfaced. In scarfing boards using cutting reels supported on axes transverse to the longitudinal axis of the board, the natural tendency is to gradually increase the depth of cut, working forward the feather edge of the completed scarf. In the present construction, the blunt end of the board to be scarfed is first cut, and the depth of cut gradually decreased. This is made possible by reversing the normal direction of rotation of the cutters, creating a forward and downward force against the board in place of a rearward and upward force. As a result, the cutters tend to hold the boards against the supporting table rather than to force the board away from the table, thereby holding the board from chattering during the cutting operation.

An added feature of the present invention lies in the fact that the entire board length may be maintained. When the cutting reels are arranged on inclined axes extending generally parallel to the longitudinal axis of the board, and the scarf is formed by moving the boards laterally beneath these cutters, it is usual practice to clamp the extremity of the board being scarfed, and to saw off this clamped extremity as the scarf cut is made, thereby wasting this clamped end of the board. In the present arrangement, no part of the board except that actually out off to form the scarf is wasted.

These and other objects and novel features of my invention will be more clearly and fully set forth in the following specification and claims.

In the drawings, forming a part of the specification:

Figure l is a side elevational View of the scarfing apparatus illustrating the construction thereof.

Figure 2 is a cross sectional view through the scarfing apparatus, the position of the section being indicated by the line 2-2 of Figure 1.

Figure 3 is a top plan view of the cutters and cutter supporting carriage removed from the remainder of the apparatus.

Figure 4 is a sectional view through the cutters and cutter supporting carriages, this view also showing the built-in knife grinders and jointers which were omitted in Figure 3 in the interests of clarity.

Figure 5 is an elevational view partly in section showing the cutter supporting carriage raising and lowering apparatus.

Figure 6 is a top plan view of the center portion of the apparatus showing the arrangement of parts therein.

Figure 7 is an end view of the board supporting table showing the manner in which the board positioning stops are supported.

Figure 8 is a cross sectional view through the table and of the clamping device for clamping the board or boards upon the table.

Figure 9 illustrates diagrammatically a portion of the movable table and table supporting base illustrating the manner in which certain of the controls are actuated by movement of the table.

Figure 10 illustrates the wiring diagram showing the electrical circuit of the apparatus.

, Figure 11 shows diagrammatically the hydraulic circuit used in controlling and operating of the apparatus.

Figure 12 is a longitudinal section through a portion of the apparatus.

Figure 13 is a diagrammatic view showing the arrangement of parts at the completion of the scarfing operation.

The scarfing apparatus is illustrated in general by the letter A and is shown in board receiving position in full lines in Figure 1 of the drawings. Figure 1 illustrates the complete apparatus but omits any showing of the board delivery apparatus or of board removal apparatus which may be used in conjunction with the scarfing machine but which do not form an actual part thereof.

In general the apparatus A includes a supporting bed or frame 10 which is shown in Figure 2 to include elongated hollow parallel beams 11 and 12 which are held in proper relation by suitable transverse braces 13 located at intervals throughout the lengths of the beams 11 and 12. The hollow beams 11 and 12 support angle members 14 and 15, respectively, which are welded or otherwise affixed to the upper surfaces of the beams 11 and 12. These angle members 14 and 15 support elongated tracks or ways 16 and 17, respectively, which in turn slidably support the movable table. While the particular shape of the tracks or ways 16 and 17 may be considered a matter of choice, the track 16 is shown as having a flat upper surface 19 while the track 17 is shown as having a tapered upper surface which cornprises substantially an inverted V in cross section. This arrangement is provided to guide the table for longitudinal movement and at the same time to hold the table from transverse movement.

The work supporting table includes a table base which is indicated in general by the numeral 20. The table base includes a pair of opposed channel members 21 and 22' which are connected by longitudinally spaced connecting webs 23. Supporting flanges 24 and 25 are secured to the channels 21 and 22 to extend longitudinally thereof and to project outwardly therefrom. These flanges 24 and 25 support replaceable slides 26 and 27, respectively, which are connected to the flanges by bolts such as 29 and 30.

The slide 26 is designed to rest upon the track 19 and to be supported thereby. The slide 27 is provided with a longitudinally extending V-shaped notch 31 in its under surface designed to fit the track 17. In other words, the table base slides upon the base frame much in the same manner as the tail stock of a lathe slides upon its bed.

The table base 20 is provided intermediate its ends with a pair of upright channel members 32 extending upwardly from opposite sides of the base in parallel opposed relation. A pair of braces 33 (Figure 1), which are channel-shaped in cross section extending from the forward part of the table base 20 to each of the uprights 32 and the brace 33 is welded or otherwise secured to these parts. A second pair of angular braces 34 extend upwardly from the rear end of the table base 20 and are welded or otherwise secured to the uprights 32. The braces 33 and 34 serve to hold the uprights 32 in upright position.

A table top assembly, indicated in general by the numeral 35, is pivotally supported between the uprights 32. The table top assembly 35 comprises a generally rectangular table top 35 (Figure 2) of boiler plate or the like which is welded or otherwise secured to a generally rectangular channel iron frame including parallel channel iron sides 37 and 39. Arms 40 and 41 extend downwardly from the frame sides 37 and 39 at a point intermediate the ends of the table top assembly. These arms 4% and 41 support bearings 42 and 43, respectively. A channel iron brace 44 (Figure l) is provided on each side of the table frame and is centrally bent as indicated at 45 in Figure 12 of the drawings to extend about a corresponding bearing 42 or 43. This channel brace 44 is preferably Welded in place and forms a means of bold- 5. ing the 'arms 40 and 41 in right angular relation to the table.

The ends of the table frame include channel members 46 one of which is shown in Figure 12 of the drawings. Additional cross members can be provided if desired. Two such cross members 37 are shown in Figures 2 and 12 of the drawings, these cross members not only holding the parallel channels 37 and 39 but also strengthening the arms 40 and 41.

The table is moved longitudinally of the base frame of the apparatus by means of the hydraulic cylinder and piston. As is illustrated in Figure 12 of the drawings, an elongated cylinder 49 is supported by angle brackets 50 secured to cross members 51 and 52 extending between the hollow beams 11 and 12 forming a part of the base frame 10. A piston of usual type is provided in the cylinder 49 and is connected to a piston rod 53. A plate 54 is secured to the bottom edges of the angle members 21 and 22 at one 'end of the table base frame 20. The piston rod 53 is connected to a bracket 55 secured to the under surface of this plate 54. Reciprocation of the piston within the cylinder 49 acts to move the table longitudinally of the base frame in either direction.

As is indicated in Figures 1 and 2 of the drawings, the uprights 32 on the table base frame 20 support at their upper ends spaced bearings 56 and 57. A shaft 59 extends through the bearings 56 and 57 and through the bearings 42 and 43 at the lower ends of the arms 40 and 41. Thus this shaft 59 pivotally connects the table top assembly to the table base.

The manner in which the table top assembly is tilted and the apparatus for performing this operation is best illustrated in Figure 12 of the drawings. A channel cross brace 60 connects the uprights 32 extending upwardly from the table base 20. A mounting plate 61 is secured to this channel member 60 intermediate the ends thereof. A bracket plate 62 is detachably secured to the mounting plate 61 and acts to support a hinge bracket 63. This hinge bracket 63 is provided with a bifurcated upper extremity 64 which is designed to accommodate a hinge pin 65 secured to one end of the hydraulic cylinder 66. The cylinder 66 contains the usual hydraulic piston and has a piston rod 67 extending from the end of the cylinder opposite that supporting the hinge plate 65. A journal 69 is secured to the extremity of the piston rod 67.

A hinge bracket 70 is secured to the under surface of each of the angle members 37 and 39 which form the longitudinal sides of the table top frame. Lever arms 71 are pivotally connected at 72 to a transfer shaft or aligned transverse pivots extending through the hinge bracket 70 and through the upper ends of the lever arms 71. A transverse shaft 73 connects the lower ends of the arms 71 and extends laterally beyond the arms. Bearing rollers 74 are pivotally supported on the ends of the shaft 73.

A shaft 75 extends between the arms 71 and a point intermediate the ends thereof. This shaft 75 extends through the journal 69 on the end of the piston rod 67. Thus reciprocation of the piston rod may act to hinge the lever arm 71 about their fixed pivots 72.

Spaced uprights 76 are mounted upon a mounting plate 77 in parallel relation. The mounting plate 77 is detachably connected to a bearing plate '79 extending across the top of the parallel channel members 21 and 22 forming a part of the table base frame 20. These uprights 76 are provided on their inner surfaces with parallel inclined grooves 30, or tracks for accommodating the rollers 74. Thus as the lever arms 71 are pivoted in a clockwise direction, the rollers 74 roll up the tracks 80 thereby causing the forward end of the table top assembly to be swung upwardly and the rear end of the table to be lowered.

Some means is provided for limiting the movement of the rollers 74 in the tracks 80. In the particular arrangement illustrated, a cross member 81 extends between the forward end of the uprights 76 and a second crossmember 82 slides between the uprights 76. Stops 83 are secured to opposite ends of the cross member 82 and extend in the track to limit the movement of the rollers 74. A threaded shaft 85 which may be manually ro tated by a hand wheel 86 extends through the cross member 81 and rotates freely therein. The threaded shaft 85 is threaded into the cross member 82 so that rotation of the threaded shaft acts to move the cross member 82 toward or away from the cross member 81 thereby adjustably supporting the stops.

The forward end of the table is equipped with board positioning stops which properly locate the boards to the scarf. The construction of these stops is best illustrated in Figures 7 and 12 of the drawings. A supporting bracket having a vertical flange 87 and a horizontal flange 89 at the lower end of the vertical flange forms a support for the stops. ends of this bracket. The vertical flange 87 is secured to the channel member 46 forming the end of the table top frame. A guide block 91 is bolted to the vertical flange 87 near the upper extremity thereof. This guide block 91 is provided with vertical grooves 92 in its inner face which act as guides for sliding movement of the stops 93. These stops 93 are elongated laterally so as to engage boards of varying widths. The stops 93 are bolted or otherwise secured as indicated at 94 to a crosshead 95 which is mounted upon the piston rod 96 of a vertically supported hydraulic cylinder 97 secured to the under surface of the bracket flange 89. Vertical reciprocation of the piston within the cylinder 97 acts to raise and lower the crosshead 95 and also the stops 93. As is indicated in Figure 12 of the drawings, the stops 93 are provided with beveled upper ends 99 so that the stops may be retracted out of the path of movement of the cutters while the table is tilted with a minimum of vertical movement. It should also be noted that the top 36 of the table is preferably provided at its forward end with a replaceable strip 100 which may be of a material considerably softer than the remainder of the table top so as to prevent injury to the cutter blades in the event the table top is tilted to too great an extent while passing beneath the cutter blades.

A means is also provided for clamping a board or plurality of boards on the table top during the scarfing operation. This apparatus is best illustrated in Figures 1 and 8 of the drawing and is designated in general by the numeral 101. As is indicated in Figure 8 of the drawings the channel member 39 forming one side of the table top frame is provided through a part of its length with an elongated track strip 102 which is held in spaced parallel relation to the base of the channel frame side by spacers 103 through which bolts 104 or other fastening means extend. The clamping means 101 is provided with a vertical mounting plate 105 having slide guides 106 and 107 projecting therefrom in parallel relation along its top and bottom edges respectively. The guide 106 is provided with a groove 109 in its under surface and the guide 107 is provided with a corresponding groove 110 in its upper surface. These grooves 109 and 110 embrace the upper and lower edges of the track member 102 and permit the clamping member 101 to move longitudinally of the table to a desired location. A set screw 111 is provided in the lower slide guide 107 to lock the clamping member in its adjusted position.

The mounting plate 105 supports a pair of upwardly and laterally curved supports 112, these supports being parallel and being held in parallel relation by the cross members 113 and 113'. The uppermost cross member 113 extends longitudinally of the moving table and approximately rnidway between the sides of the table. This cross member 113 supports an hydraulic cylinder 114 projecting upwardly therefrom and the piston rod 115 connected to the cylinder piston extends down through the Triangular braces 90' reinforce the.

cross member 113 and is connected to the central hub 116 of a bearing plate 117.

A generally rectangular pressure plate 119 is adjustably secured to the bearing plate 117 by bolts 12%. These bolts 120 are threaded into the pressure plate 119 and extend through apertures in bearing plate 117. A series of spacing washers 121 of various thicknesses encircle the bolts 120 between the heads thereof and the bearing plate. These washers 121 are provided with radially extending slots 122 in a side thereof so that the washers may be removed when the bolts 120 are loosened. These washers may then be replaced between the bearing plate and the pressure plate to regulate the normal elevation of the pressure plate.

A set of spaced parallel board gripping bars are supported by the pressure plate to extend longitudinally of the table. Each bar 123 is supported by a pair of longitudinally spaced bolts 124 and springs 125 encircle the bolts 124 so that the distance between the pressure bars and the plate 119 may be regulated. These bars take care of any irregularities in board thicknesses and permit parallel boards of different thicknesses to be simultaneously clamped.

The apparatus for cutting the scarf in the boards is shown in its relation to the remainder of the apparatus in Figures 1 and 2 of the drawing and is shown in more detail in Figures 3, 4, and 6 of the drawing. The cutting reels are mounted for vertical adjustment in an upright framework indicated in general by the numeral 126 which straddles the frame and the table structure. The frame 126 includes opposed cornerposts including two spaced front cornerposts 127 and two spaced rear cornerposts 129. As is indicated in Figure 2 of the drawing the structure includes a laterally extending base frame portion extending laterally from both sides of the base frame and inclined channel shaped braces 131 extending upwardly from the base frame 130 to the respective co:- nerposts to further strengthen the frame. Angle members 132 extend between the front and rear posts 127 and 129 and also between the inclined braces 131 on each side of the apparatus. A platform 133 is supported by the angle member 132 and 133 on each side of the apparatus on which the operator may stand to inspect the cutting apparatus.

Hollow beams 134 formed of two channel members in edge abutting relation extend between the cornerposts 127 and 129 on each side of the apparatus. Similar hollow beams 135 extend between the upper extremity of the cornerposts. An upwardly peaked superstructure rests upon the top of the upright frame described as is indicated in the drawing. As shown in Figures 5 and 6 of the drawings, this superstructure includes a generally rectangular frame of channel shape cross section having a parallel front and rear frame members 136 and generally right angular side channel members 137, best shown in Figure 2. Upwardly converging frame members 139 extend upwardly from the end frame members 136 above the side frame members 137 to support a horizontal central frame member 140. Diagonally extending angle braces 141 extend upwardly from the end channel members 136 to the top central channel members 149 to further brace these parts. The frame members 140 act to support the braces 142 of gear housings 143. The two gear housings 143 support a transverse shaft 144 having a hand wheel or crank 145 at one end by means of which the shaft 144 may be rotated.

A vertical tubular enclosure 146 extends downwardly from the top frame portion 14b to the side channel frame members 137 to enclose the upper portions of cutter mechanism supporting bars 147 which act to support the cutting mechanism and to permit vertical adjustment thereof. I

' The upper ends of the rods 147 are externally threaded and these rods are threaded into internally threaded sleeves 149 rotatably supported by suitable thrust bearings and 151 in the gear housing 143. A worm wheel 152 is keyed to the outer surface of the sleeve 149 and rotates therewith. Worms 153 are mounted upon the transverse shaft 144 to rotate in unison therewith. Rotation of the shaft 144 acts through the worms 153 to rotate the worm wheels 152 which in turn rotates the sleeves 149. Rotation of the sleeves 149 acts to raise and lower the rods 147 in unison.

As is best indicated in Figure 6 of the drawings, the cornerposts 127 and 129 include vertically grooved tracks 154 which act to vertically, slidably support the cutting reel frame which is indicated in general by the numeral 155. The grooves 156 on all of the cornerposts open inwardly toward the longitudinal center of the apparatus. The cutting reel frame is provided with four slide guides 157 having parallel outwardly directed flanges 159 which. are slidable in the grooves 156. As indicated in Figure 5 of the drawings, the rods 147 extend down into the frame 155 to support this frame and are held from rotation relative to the frame by nuts 160.

The cutter frame 155 is generally rectangular in plan having spaced parallel sides 161 and 162, a forward end 163 and a parallel rear end 164. As may be seen in Figures 1 and 4 of the drawings, the sides 162 are of substantial depth so as to prevent any danger of the frame tilting in its vertical supports. As may be seen from Figures 2 and 4 of the drawings, the front and rear walls 162 and 163 have their center portions 165 and 166 respectively, materially reduced in height so that the table and the boards to be scarfed may pass beneath these end walls 163 and 162. In other words, during the actual cutting operation, the cutting reel frame 155 actually straddles the table and the boards supported thereon.

While the boards to be scarfed are clamped frmly to the table during the scarfing operation, the clamp is located at some considerable distance from the end of the board being scarfed. Accordingly, means have been provided for holding the boards down against the table as they approach the cutters and during the scarfing operation. Due to the fact that the boards may vary in thickness and due to the further fact that more than one board may be simultaneousy scarfed the hold-down means includes a series of laterally spaced members each of which is individually urged against the boards. These hold down members are best illustrated in Figures 3 and 4 of the drawings. The series of spaced L shaped bracket supports 167 are attached to the rear side 162 of the cutter reel frame. These brackets 167 include a vertical flange 169 having a pair of vertically elongated slots 17% and 171 therein. tuds 172 and 173 are anchored in vertically aligned relation to project rear- Wardly from the frarne side 162. These studs extend through the slots 17d and 171, respectively. Clamping nuts 174 are mounted upon the studs 172 and 173 to clamp the brackets 167 in adjusted relation with respect to the frame. The brackets 167 also include a forwardly extending horizontal flange 175 at the upper extremity of the vertical flange. The flanges 175 are provided with bifurcated extremities 176. Vertical guide sleeves 177 having transverse bearings 179 near their upper extremity are supported in the bifurcated ends 176 of the brackets by means of transverse pivots 180. The sleeves 177 slidably support push rods 181 having bifurcated clevices 182 at their lower ends. Lock nuts 183 are threaded on the upper ends of the push rods to permit adjustment of the length of these rods. Springs 184 encircle the push reds 181 between the clevices 182 and the lower ends of the sleeves 177.

The lower extremities of the vertical flanges 169 of the brackets 167 are bifurcated as indicated at 185. Hold down arms 186 are pivotally supported at 137 between the spaced lower end portion of the bifurcated bracket ends 185. The clevices 182 straddle the hold down arms 186 at a point substantially spaced from the pivot 183 and are pivotally connected thereto at 187.

It will be seen that the hold down arms 186 act to guide the forward ends of the boards clamped upon the movable table beneath the cutter reels and prevent any warpage of the boards from holding the forward ends thereof raised above the surface of the table during the scarfing operation.

A pair of transverse parallel shafts 189 and 190 are supported by suitable bearings 192 and 193 on the sides 161 and 162 of the cutting reel frame. A platform 194 is connected to the frame side 162 to support the motor 195 connected by a suitable coupling 196 to the shaft 189. A similar platform 197 supports a motor 199 connected to the shaft 190 by a coupling 200.

Cutting reels 291 and 2112 are mounted upon the shafts 189 and 190 to rotate in unison therewith. These cutting reels are provided with angularly spaced blades 203 and 204, respectively. The cutting reel 201 is designed to provide a rough cut and during this cut the major portion of the wood to be removed is cut away. The second reel, 202, is designed to provide a smooth finish cut so that the scarf has a surface finish comparable to that produced by a planer or the like.

Means are also provided to hold down the boards between the cutting reels. The frame 155 is provided with a cross member 205 extending parallel to the reels and between the same, the cross member being integral with the sides 161 and 162. The cross member 205 is provided with a series of laterally spaced vertical apertures 206 extending thereto for the accommodation of push rods 207. The upper ends of the push rods 207 are threaded to accommodate lock nuts 209 to limit downward movement of the push rods. Laterally spaced shoes 210 are mounted on the bottom ends of these push rods 287 to move vertically in conjunction therewith. The shoes 210 are provided with a transverse groove 211 in their upper surfaces, the sides of this groove embracing the lower edge of the cross member 205 and holding the shoes from rotation. The rear ends 212 of the shoes are preferably beveled upwardly to a slight extent to guide any upwardly extending portion of the board down beneath the shoes. Springs 213 encircle the push rod 207 between the upper surfaces of the shoes 210 and the bases of the counterbores 214 to normally urge the shoes 210 downwardly against the surfaces being cut.

The boards are also held down against the table after the scarfing cut has been completed. The wall 163 of the frame 155 is provided with an integral rearwardly projecting portion 215 which projects toward the cutting reel 202. This projection 215 is provided with a series of laterally spaced apertures 216 thereto which are designed to extend vertically and to slidably support push rods 217. The push rods 217 are limited in their downward movement by nuts 219 threaded on the upper ends of the push rods. Shoes 220 are mounted on the lower ends of the push rods 217, these shoes having a transverse groove 221 in their upper surface designed to embrace the lower end of the projection 215 to keep the shoes from turning. Springs 222 are interposed between the upper surfaces of the shoes 220 and the bases of counter bores 223 so as to urge the shoes downwardly. The shoes 220 are shaped somewhat similarly to the shoes 210 and are provided With beveled rear edges 224. The shoes 210 and 220 may serve to some extent as chip breakers although the rotation of the cutters is such as to prevent chips from splitting from the board.

The cutting reels 201 and 202 rotate in a clockwise direction as viewed in Figure 4. As the boards to be scarfed move inwardly from the right of the cutters, the direction of rotation is such as to tend to urge the boards downwardly against the table and also to assist in the forward movement of the board. This is a rather unique feature of the present invention as in planing and surfacing operations it is normal practice to rotate the cutters "10 in a direction opposite the movement of the board. In other words, most planing and surfacing machines rotate the cutters in a direction opposite to the direction of rotation of the present device.

L-shaped brackets 225 are removably mounted upon the sides 161 and 162 of the frame for supporting cross members 226 extending across the frame above the cutter reels 201 and 202. These cross members 226 slidably support built-in knife grinder and jointer apparatus which is indicated in general by the numeral 227. These grinding and jointing devices are employed to sharpen the individual blade of the cutting reels while the reels are in place in the apparatus.

Cross members 229 and 230 also extend between the sides 161 and 162 of the frame 155 in spaced relation to the cutting reels. These cross members reinforce the frame and also tend to guide the chips upwardly during the operation of the cutting reels. A hood is also provided above the cutting reel frame 155 which is connected to a source of partial vacuum for withdrawing the chips during the operation of the apparatus. This hood includes a lower rectangular portion 231 (Figures 5 and 6) which is detachably connected to the upper surface of the frame 155 and which can be removed when the jointing and grinding means 227 are used to sharpen the blades. Due to the fact that the knife grinders are removable, they are shown only in Figure 4 of the drawings.

The upper hood portion 232 includes a lower rectangular portion 233 and a tapered top portion 234 leading to an outlet pipe 235 which is connected to the source of partial vacuum. When the apparatus is in operation, air is drawn upwardly from beneath the cutters carrying the chips through this outlet 235.

While the particular location of the control apparatus is to some extent a matter of choice, Figure 9 is designed to illustrate somewhat diagrammatically the location of certain of these controls. The specific manner in which the control operates will be later described in greater detail.

Figure 9 illustrates at 20 a part of the base frame of the table and illustrates at 10 a part of the base of the supporting frame. Numeral 236 illustrates a deceleration valve which is connected in series with the hydraulic line of the table operating cylinder 49. As the table frame 20 moves to the left, a cam shoulder 237 engages a valve actuating roller 238 and operates the Valve 236 in a manner to decelerate the movement thereof. As the table moves with considerable speed, the valve 236 is useful in stopping the movement of the table after the scarfing out has been made.

Figure 9 also illustrates a limit switch 239 which is engaged by the cam 240 at the completion of the cutting stroke of the table. This limit switch 239 acts to a timer which will be later described in detail and which holds the table stationary at the end of its stroke for a time sufficient to unload the scarfed board from the table.

Figure 9 also illustrates a cam block 241 which engages a limit switch 242 at the end of the return movement of the table. This acts in a manner which will be later described to raise the board locating stops into position to engage the forward end of the board or boards next placed upon the table.

This same cam 241 also engages the limit switch 243' to stop the cycle until it is again initiated by the operator.

wise direction by a suitable motor. When the table has assists advanced beyond the cutters and has been tilted down into horizontal position, the board clamping means is released. The roll or rolls 245 may then be forced downwardly against the surface of the board by a hydraulic cylinder 246 or other suitable means so that the upper surface of the board is engaged and the board is propelled forwardly until it is engaged between additional driven motors not illustrated in the drawing for removal from the forward end of the table.

The control of the apparatus is best illustrated from an examination of Figures and 11 of the drawings. Figure 10 illustrates the first cutter motor 195, the second cutter motor 199, and a hydraulic pump motor 247 connected in parallel to a three-phase supply line including the conductors 249, 250 and 251. Motor controlling switches 252, 253 and 254 are in the circuits to these motors so that they can be controlled. The motor switches are actuated by a starting circuit which will be later described in detail. The line wires 249 and 250 are connected to the coil 255 of a voltage reducing transformer 256, the other coil 257 of which supplies current to the line wires 259 and 260. All of the control mechanism, with the exception of the three motors described, are connected between these line wires.

A normally closed master switch 261 is provided in the line wire 259 so that all of the electricity to the apparatus may be cut otf in an emergency. The line wire 259 is connected through a switch 262 to a conduct-or 2653 leading to the coil 254 of the starting switch 254 for starting the hydraulic motor. A holding circuit by-passes the switch 262 and includes a switch 262' forming a part of the starting switch 254. Thus, the circuit to the motor 247 remains closed after momentary operation of switch 262 until the circuit is broken by the master switch 261 or by strategically located safety switches 25$. The conductor 263 is also connected by a conductor 264 to a cutter motor operating switch 265 which is connected by conductors 266 and 267 to the coils 252' and 253' of cutter motor starting switches 252 and 253. The second terminals of the starter switches 252, 253 and 254 are all connected to the line wire 260 through properly located safety switches 268.

A holding circuit by-passes the switch 265 to hold the starter switch coils 252 and 253' energized. This hold ing circuit includes a switch 265 which maintains the switch coils energized once the switch 265 has been momentarily closed until the circuit is otherwise broken. It will be noted that the cutter motors cannot be operated unless the hydraulic motor is already in operation.

The line wire 259 includes a switch 259' useful in preventing operation of the various table controls out of proper sequence. This switch 259' forms a part of starting switch 253 and closes the portion of the circuit beyond the motors when the motors are in operation.

The line wire 259 is connected through a normally open foot switch 269 to a conductor 270 leading to a solenoid 271i forming a part of a solenoid controlled pilot operated four-way valve 272 (Figure 11) controlling the flow of hydraulic fluid to the clamp cylinder 114 and the tilt cylinder 66. The other terminal of the solenoid 271 is connected to the line wire 260.

The line wire 25% is also connected through a limit switch 273 in the path of movement of the tilt cylinder piston rod 67 to a conductor 274 leading to a solenoid 275 forming a part of a double acting solenoid operated four-way valve 276 (Figure 11) controlling the flow of fluid to the stop pin cylinder 114. This line wire 259 is also connected through a limit switch 277 to a conductor 279 connected to a normally closed timer operated switch 280. The switch 28% leads to a conductor 281 leading through a normally closed push button operated switch 282 to a conductor 283 leading to a solenoid 234 leading to a solenoid control pilot operated four-way valve 285 (Figure 11) controlling the flow of fluid to the table operating cylinder 49. The second ter- 12 minal of the solenoid 284 is connected to the line wire 260.

The closing of the limit switch 277 while the normally closed switches 280 and 282 are closed, acts in a manner which will be later described to advance the table beneath the cutters. A second conductor 286 leads through a push buton switch 237 from the conductor 259 into the solenoid 284 so that the table may be advanced by push button control rather than automatically when desired.

The conductor 259 is also connected through a normally open limit switch 239 to a conductor 29% leading to one terminal of a solenoid 291 forming a part of the valve 272 previously described. This valve acts to untilt and unclamp the board upon the table.

As was previously described, the limit switch 239 is in the path of movement of the table and is closed at the completion of the cutting stroke. The closing of this circuit also closes a circuit from conductor 2% to a conductor 292 leading to a timer coil 293. Operation of the timer coil 293 acts to cause a normally open timer operated switch 294 to close and to open the previously described normally closed timer operated switch 280 in the circuit to the solenoid 234 of the table advancing valve control, thus permitting the valve 285 to return to neutral position. A circuit is thus closed from line wire 259 through conductor 295 and the normally closed limit switch 243 and through the timer switch 294 to a conductor 2% leading to the timer coil 293, the opposite terminal of which is connected to line wire 260. A circuit is also initiated by the closing of the timer switch 294- through conductor 237 to a normally open timer control switch 299 which is closed after a predetermined period of waiting. The switch 292 is connected by a conductor 30% through a normally closed push button switch 301 to a solenoid 302 forming a part of the valve 285 controlling the flow of fluid to the table operating cylinder 49. Thus, after a predetermined period of time as determined by the timer, the table is retracted to its starting position, this movement continuing until the circuit is opened through the limit switch 243 in the path of movement of the table.

The push button switches 287 and 301 are connected for operation in unison. The switch Sill is designed to open any circuit to the table retracting cylinder operating solenoid in the event the table is being advanced by the push button 287. The table retracting solenoid is also connected by a by-pass conductor 303 to the line wire 259, this conductor 323 including a push button switch 384. The push button 394 permits actuation of the solenoid 302 manually when desired and the push button 304 is connected to the previously described normally closed push button 282 so that the circuit to the table advancing solenoid 284 must be broken when the table retracting solenoid is energized.

The momentarily closed switch 24 2 has been described as being in the path of movement of the retracting table. As the table approaches its standing position, a circuit is closed from the line wire 259 through the switch 242 and a conductor 305 to a solenoid 3% forming a part of the stop pin controlling valve 276. Actuation of the solenoid 306 acts to project the pins upwardly into position to locate a board upon the table.

The line wire 259 is also connected through a second blade 269' of the foot switch 269 to a conductor 311 leading through relay switch 308 to a solenoid 312, the other terminal of which is connected to line wire 269. A normally closed limit switch blade 239', operable in unison with limit switch 239, is provided in conductor 307 leading to the relay coil 309. The relay coil 3439 closes a pair of switches 398 and 363'. The switch 3&8 is in parallel with the switch 26?. The switch 3438' acts to close a circuit to the solenoid 312 from line wire 259 when the relay coil 369 is energized. Switch 3% also closes a holding circuit to maintain the relay coil 399 .13 energized as long as the "normally closed limit switch 239' is closed.

When the foot switch 269, 269 is closed momentarily, the relay 309 is energized, closing a circuit to the solenoid 312 and closing the holding circuit maintaining the solenoid circuit closed. When the table reaches the end of the cutting stroke, limit switch 239 is closed and blade 239 thereof is opened, breaking the relay circuit. However, a second circuit, from line wire 259 through limit switch 243 and conductors 310 and 311, keeps this solenoid 312 energized until the completion of the return stroke of the table, at which time the normally closed limit switch 243 is opened.

Energization of the solenoid 312 actuates the spring biased solenoid operated valve 313 which acts in a manner later described to. permit fluid pumped by the hydraulic pump to by-pass back into the reservoir without building up the pressure necessary to operate its relief valve.

The hydraulic circuit of the apparatus is illustrated in Figure 11 of the drawings. The motor 247 is connected to a pump 314 through a strainer 315 from the reservoir or tank illustrated diagrammatically at 316. The fluid pumped into the pressure line 317 communicates with a relief valve 319 which opens under abnormal pressures to permit the flow of fluid to the tank 316. The relief valve 319 is also connected by a vent passage 320 to the valve 313. This valve 313 is normally closed but upon actuation of the solenoid 312, which occurs at the completion of each operating stroke and retracting stroke to open the valve, the vent line 320 is connected to the tank 316. Thus between cycles, the fluid may be by-passed back to the tank or reservoir without operating the relief valve 319.

The fluid under pressure is connected through a check valve 321 to the double acting valve 272. The valve 272 includes a pilot valve 322 and a main valve 323. Movement of the pilot valve 322 is controlled by opera tion of the solenoids 271 and 291. Operation of the main valve 323 is controlled by the position of the pilot valve.

When the foot switch 269 is operated to start the operating circuit of the apparatus the solenoid 271 is energized moving the pilot valve 322 into the position illustrated. This causes fluid under pressure to extend through the passage 324 to supply pressure to thechamber 325 at the right of the main valve 323, thus permitting fluid under pressure to flow through the passage 326, the main valve 323 and into the conduit 327 leading to the upper end of cylinder 114. This action tends to force the piston rod 115 downwardly, thus operating the clamping mechanism against the board or boards placed upon the table of the machine. A guide 329 (Figure 8) is provided on the table top 36 for aligning the boards on the table.

Fluid from the lower end of the cylinder 114 flows through the conduit 330 to a pressure controlled valve 331. This pressure may open the check valve 332 and flow through the conduits 333 and 334 and through the main valve 323 to the tank return line 335.

The line 327 is also connected to a conduit 336 leading to a pressure control valve 337. While the piston rod 115 of the clamping cylinder 114 is in movement, insuflicient pressure is built up in the valve 337 to permit a flow of fluid therethrough. However, when the clamping cylinder is in board clamping position, this pressure increases and flows through the valve 337 into the conduit 339 leading to the right hand end of the tilting cylinder 66. This fluid under pressure forces the piston rod 67 to the left operating the lever arm 71 in a manner to tilt the table 36.

The fluid from the left side of cylinder 66 may flow through the line 340 joining with the conduit 334 which conducts the fluid through the main valve 323 to the return line 335. During the portion of the operation thus described, the board has been firmlyclamped against '14 the table and the table has been tilted to a predetermined angle.

As the tilting movement of the table is completed, the limit switch 273 which is preferably mounted upon the adjustable stop member 82 (Figure 12) is operated closing a circuit to the solenoid 275 forming a part of the locating pin operating mechanism. Actuation of the solenoid 275 acts to move the valve element 341 of the valve 276 in to the position shown in full lines in Figure 11 from its opposite position. Accordingly, pressure from the pressure line 317 flows through a conduit 342 and the valve element 341 to the conduit 343 leading to the upper extremity of the stop pin cylinder 97. This causes the stop pins to be lowered beneath the surface of the table so as to be out of the path of movement of the cutter blades as the table is advanced.

Fluid from the lower end of the cylinder 97 is free to flow through the conduit 344, the valve element 341 and to the return line 345.

As the stop pin 93 reaches fully retracted position, the switch 277 is closed, closing the circuit which has been described to the solenoid 284 forming a part of the table movement controlling valve 285. The valve 285 is somewhat similar to the pilot operated valve 272 previously described but has a central intermediate position of the valve element as well as extreme positions thereof. In Figure 11 of the drawings, the valve 285 is shown in its intermediate position.

Fluid from the pressure line 317 flows through the conduit 346 and into the valve 285. When the solenoid is actuated, the pilot valve element 347 moves to the left. The pressure may then pass to the valve element 347 to the passage 349 leading to the pressure chamber 350 to the left of the main Valve element 351. This forces the main valve element to the right and pressure is communicated through the main valve element 351 to the line 352 leading to the right end of the cylinder 49.

The piston within the cylinder 49 then forces the piston rod 53 to the left moving the table along its supporting base and moving the board to be scarfed successively between the cutting reels and the table. The scarf is cut in the end of the board during this movement of the table.

The fluid from the left side of the piston in cylinder 49 flows through the conduit 353 to the deceleration valve 236. This deceleration valve 236 is provided with a valve element 354 which permits the flow of fluid there-through without interruption. However, as the table nears the end of its stroke the valve element push rod 238' is actuated by the cam 240 in a manner to shift the valve element 354 into position to restrict the flow of fluid through the valve. The movement of the table is accordingly decelerated.

The fluid flowing from the left end of the cylinder 49 passes through the valve 236 and into the conduit 355 leading through the flow controlled valve 356. This flow control valve may be actuated to restrict the flow and so as to regulate the speed of the table movement. The fluid then flows through conduit 357, the main valve element 351, and to the return line 359.

As the table reaches the end of its cutting stroke, the limit switch 239 is actuated closing a circuit to the solenoid 291. Enel'gization of the solenoid 291 acts to urge the pilot valve element 322 to the left from the position shown in full lines. This acts to permit fluid to flow through the pilot valve element 322 to the passage 360 leading to the pressure chamber 361 at the left of the main valve element 323 and acting to shift this main valve element to the right from the position shown in full lines in Figure 11. A fluid under pressure then flows into the conduit 334 leading to the left end of the tilt cylinder 66. This causes movement of the piston rod 67 to the right, swinging the table down into horizontal position. Fluid from the right end of the cylinder 66 is communicated through, the conduit 339 to the Valve- 337 where it passes by the check valve 362 and flows through the conduit 336, the main valve element 323 and to the return line 335.

When sufiicient pressure builds up due to the retraction of the piston in cylinder 66 to operate the valve 331, a fiuid will flow through this valve and through the conduit 33% to the lower end of the clamping cylinder 114. This action releases the clamping force against the board on the table. A fluid from the upper end of cylinder 114 may flow through the conduit 327, the main valve element 323 and to the drain line 335.

As was previously described, the closing of the limit switch 239 also closes a circuit to the timer coil 293. Thus after a predetermined time delay during which the board or boards are removed from the table a circuit is closed to the solenoid 302. Energization of the solenoid 3&2 acts to move the pilot valve element 347 to the right from the center position illustrated. This causes fluid under pressure to communicate through passage 363 to the pressure chamber 364 to the right of the main valve element 351, moving this main valve element to the left from the central position illustrated. In this position of the valve, fluid under pressure may flow through the conduit 357, pass the check valve 365 arranged in parallel with the fluid control valve 356 through the conduit 355, pass the check valve 366 in valve 236 and into the left hand end of cylinder 49 drawing the piston rod 53 and the table to the right towards starting position. The fluid from the right end of cylinder 49 is free to flow through the conduit 352 and the main valve element 351 to the return line 359.

As the table nears the completion of its return stroke, the limit switch 242 is operated. A momentary closing of the switch 242 closes a circuit to the solenoid 306 forming a part of the stop pin operating valve 276. Energization of the solenoid 356 acts to move the valve element 341 to the right from the position illustrated. As a result fluid under pressure flows from the conduit 342. through the Valve element 341 to the conduit 34% communicatin with the lower end of cylinder 97. This causes the stop pins to be raised into board locating position. Fluid from the upper end of the cylinder 97 can flow through the conduit 343 and the valve element 341 to the return line 345.

From the foregoing description it will be clear that, when it is desired to operate the machine to scarf a board or series of boards, it is only necessary to turn on the motor driving the hydraulic pump and to turn on the cutter motors. After the board has been placed upon the table against the locating stop pins, the foot switch is operated starting the apparatus in movement. The clamping cylinder is first actuated to clamp the board. As soon as the board is clamped, the table is swung into a tilted position. At the completion of the tilting operation, the stop pins are located in lowered or retracted position. As soon as this operation is completed, the table starts into movement moving the table and board beneath the cutters to cut the scarf in the board. As the table finishes its stroke it is automatically tilted down into normal horizontal position and the clamping means are released. After a suitable adjustable period delay to permit the unloading of the board from the table, the return movement of the table is started. As the table completes its stroke, the stop pins are again projected upwardly into board locating position. When the cycle is completed, the by-pass valve 313 is open permitting the fluid to by-pass into the reservoir until the start of the next cycle.

It will be noted that the cutter motors cannot operate unless the hydraulic pump is in operation but the various operations may be accomplished while the cutter motors are stationary so that the apparatus can be properly adjusted if a special switch for this purpose is provided. Normaliy, in the system described, the cutter motors must be in operation before the board may be clamped, the 'stop' pins lo wered'or the table may be tilted or moved. However, by providing a switch'368 (Figure 10) in parallel with the relay actuated switch 259', cycling of the operations with the cutter motors off can be effected. When such a switch 368 is used, it is placed in such a location that it cannot well be accidentally operated to prevent danger of injury to the apparatus. It will also be noted that the table can be advanced and retracted by push button control. As a result, the table may be moved beneath the cutters While at a desired angle of tilt to cut a scarf of proper length and the cutters may then be adjusted vertically to proper relation with the table. As is indicated in Figure 2 of the drawings, vertical threaded rods 367 may be supported in vertical bearings 369 on the lower cross members 134 of the frame 126 beneath the sides 161 and 162 of the cutter reel frame 155. Internally threaded sleeves may encircle these rods 367 above the bearings 369 to adjust the height of these rods 36.7. When the frame supporting the rotating cutters is at a desired elevation, the rods 367 are adjusted to en gage the under surface of the frame 155 to prevent this frame from lowering accidentally into the path of movement of the table. The rods 367 also make and hold the fine adjustment of height of the cutters, and main tain parallelism between the cutters and the table.

In accordance with the patent statutes, I have described the principles of construction and operation of the scarfing apparatus, and while an endeavor has been made to set forth the best embodiment thereof, it is desired to point out that this is only illustrative of a means of carrying out the invention and that obvious changes may be made within the scope of the following claims Without departing from the spirit of the invention.

I claim:

1. A board scarring machine including an elongated board supporting table, means movably supporting said table for longitudinal movement of said table, a table top forming a part of said table, means tiltably supporting said table top on a transverse horizontal axis intermediate the ends of said table, means for tilting said table between horizontal position and tilted position, means operable, upon actuation, to operate said tilting means to tilt said table and hold said table in tilted position, cutter means supported above the path of movement of said table in tilted position, means moving said tilted table beneath said cutter heads to a terminal position in which the board is scarfed, and means controlling said tilting means operable by movement of said table upon reaching said terminal position to actuate said tilting means to return said table to horizontal position.

2. The structure of claim 1 and including means operable by movement of said table into said terminal position for actuating said table moving means to return said table to starting position.

3. The structure of claim 1 and including means oper able by movement of said table into said terminal position for actuating said table moving means after a predetermined time delay to return said table to starting position.

4. A board scarfing machine including an elongated board supporting table, means movably supporting said table for longitudinal movement of said table, atable top forming a part of said table, means tiltably supporting said table top on a transverse horizontal axis intermediate the ends of said table, means for tilting said table between horizontal position and tilted position, means operable, upon actuation, to operate said tilting means to tilt said table and hold said table in tilted po sition, cutter means supported above the path of movement of said table in tilted position, table reciprocating means connected to said table to move the same while tilted from a starting position to a terminal position in which the board is scarfed means controlling assassin tilting means actuated by movement of said table into said terminal position operating said table tilting means to tilt said table into horizontal position, means controlling said table reciprocating means to dwell the operation thereof in said terminal position for a predetermined time period and then to return said table to said starting position. I

The structure of claim 4 and including 'meanfs c'ontrolling said table reciprocating means to stop said table in said starting position. y g 6. A scarfing apparatus including an elongated board supporting table, a tiltable top'on said table, the top being tiltable on a horizontal axis transversely of the longitudinal table axis, cuttermeans, means supporting said cutter means "above the level of said table in tilted position, means supporting said cutter and table for relative movement longitudinally of the table between two extreme positions, table tilting means to tilt said table between horizontal position and tilted position, table reciprocating means connected to said table for reciprocating said table between said two extreme positions, means controlling said table tilting means to tilt said table, control means for said table reciprocating means actuated by the tilting of said table into tilted position to actuate said table reciprocating means to move said tilted table from one extreme position to the other, and means controlling said table tilting means operable by movement of said table into said other extreme position to actuate said table tilting means to return said table to horizontal position.

7. The structure of claim 6 and including means controlling said table reciprocating means operable by actuation of said table into said other extreme position to reciprocate said table into said one extreme position.

8. The structure of claim 6 and including means controlling said table reciprocating means operable by actuation of said table into said other extreme position to reciprocate said table into said one extreme position, and means controlling the operation of said table reciprocating means operable by movement of said table into said one extreme position to stop said table in said one extreme position.

9. The structure of claim 6 and including means controlling said table reciprocating means operable by actuation of said table into said other extreme position to reciprocate said table into said one extreme position after a predetermined time delay.

10. The structure of claim 6 and including means controlling said table reciprocating means operable by actuation of said table into said other extreme position to reciprocate said table into said one extreme position after a predetermined time delay, and means discharging the board from said table during said predetermined time delay.

11. A board scarfing machine including an elongated board supporting table, means movably supporting said table for longitudinal movement of said table, a table top forming a part of said table, means tiltably supporting said table top on a transverse horizontal axis intermediate the ends of said table, means for tilting said table between horizontal position and tilted positions, means operable, upon actuation, to operate said tilting means to tilt said table and hold said table in tilted position, cutter means supported above the path of movement of said table in tilted position, clamping means engageable with the board for clamping the same upon said table top, and means controlling said talble tilting means for actuating said means operable upon actuation to operate said tilting means for actuating the same when said clamping means is in clamping position.

12. The structure of claim 11 and including means controlling said clamping means upon movement of said table into said terminal position to release said clamping means.

13. The structure of claim 11 and including means 18 controlling said clamping means upon movement of said table into said terminal position to release said clamping means, board discharging means for moving the board from said table, and means controlling said board discharging means operated by movement of said table into horizontal position for actuating said board discharging tion, cutter means in the partner movement of a board on said tilted table top, board clamping means engageable with a board on said table top to hold the board thereupon, means controlling said tilting means and operable by movement of said clamping means into clamping position to tilt said table, and means connected to said table to reciprocate the same while tilted beneath said cutter means between a starting position to a terminal position.

15. The structure of claim 14 and including retractable stop means engageable with the end of a board on said table, means connected to said stop means for retracting and projecting the same, and means controlling the opera tion of said stop means actuated by movement of said table into tilted position to retract said stop.

16. The structure of claim 14 and including means controlling said reciprocating means operated by movement of said table into tilted position to move said tilted table beneath said cutter means.

17. The structure of claim 14 and including retractable stop means engageable with the end of a board on said table, means connected to said stop means for retracting and projecting the same, and means controlling the operation of said stop means actuated by movement of said table into tilted position to retract said stop, and means controlling said reciprocating means operated by movement of said stop means into retracted position to move said tilted table beneath said cutter means.

18. The structure of claim 14 and including means controlling said reciprocating means operated by movement of said table into tilted position to move said tilted table beneath said cutter means, and means controlling the operation of said tilting means operated by movement of said table reciprocating into said terminal position to untilt said table top.

19. The structure of claim 14 including means controlling said reciprocating means operated by movement of said table into tilted position to move said table beneath said cutter means, and means controlling said clamping means operable by movement of said table into untilted position to release said clamping means.

20. The structure of claim 14 and including retractable stop means engageable with the end of a board on said table, means conneected to said stop means for retracting and projecting the same, and means controlling the operation of said stop means actuated by movement of said table into tilted position to retract said stops, means controlling said reciprocating means operable by move ment of said stops into retracted position to reciprocate said table to terminal position and back to starting positron, and means controlling said stop means operable by return of said table to starting position to project said stop means.

21. A scarfing apparatus including an elongated board supporting table, a tiltable top on said table, the top being tiltable on a horizontal axis transversely of the longitudinal table axis, cutter means, means supporting said cutter means above the level of said table in tilted position, means supporting said cutter and table for relative movement longitudinally of the table between two extreme positions, table tilting means to tilt said table between horizontal position and tilted position, table reciprocating means connected to'said table for recipro References Cited in the file of this patent UNITED STATES PATENTS 10 97,476 Brown Dec. 7, 1869 121,264 Wamer Nov. 28, 1871 312,444 Disston Feb. 17, 1885 347,125 Perry Aug. 10, 1886 415,435 Baker Nov. 19, 1889 15 20 Tromanhauser Dec. 15, 1891 Kilian, Aug. 18, 1896 Mayhew Apr. 11, 1905 Krutslch Apr. 20, 1909 Solem Nov. 4, 1913 Neal Oct. 5, 1926 Pennock Nov. 7, 1933 Kampmeier May 30, 1939 Stuart May 8, 1945 Norton May 7, 1946 Pearson Aug. 15, 1950 Smyth Apr. 17, 1951 FOREIGN PATENTS Great Britain Aug. 14, 194

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