US3026793A

US3026793A - Printer

Info

Publication number: US3026793A
Application number: US733416A
Authority: US
Inventors: Earl D Clark
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-05-06
Filing date: 1958-05-06
Publication date: 1962-03-27
Anticipated expiration: 1979-03-27

Description

March 27, 1962 E. D. CLARK 3,026,793

4 PRINTER Filed May e, 1958 2 Sheets-shat l QII E 1 542/. D. CLAE/C IN V EN TOR.

" if BY ATTOEWL" y E. D. CLARK PRINTER 2 Sheets-Sheet 2 Filed May 6, 1958 -W H -HIH K V, PM P. w w Am W A AN: 0 mul Q N W n L R J mm a Q M B llnited States Patent 3,026,793 PRINTER Earl D. Clark, Willits, Calif. (Covelo, Calif.) Filed May 6, 1958, Ser. No. 733,416 6 Claims. (Cl. 101-44) The present invention relates to a printer, and in more particular to a hammer type printer, and to one or more such printers in combination with a conveyor. A particular use for such printers is in the lumber industry for the end marking of boards and timbers.

In saw mills, it is desirable to mark the ends of the various boards and timbers to show the source of such lumber, its quality, variety, or kind, and its dimensions. Machines or devices which will do such marking have been constructed and are in use but they are too complicated and expensive, and do not do the desired job in a satisfactory manner. The best time to do such marking is right after the lumber leaves the trim saws and while it is on the conveyor from the trim saws.

Thus, it is an object of the present invention to devise a printer that is adapted to mark the ends of lumber while it is on the takeoff conveyor from the trim saws.

The lumber to be marked varies in thickness from time to time, and so, while it is possible to mount such a printer above the conveyor and the lumber thereon, it is more desirable and an object of the present invention to mount such a printer below the conveyor where the varying thicknesses of the lumber will not be a factor in the construction or operation of the printer. However, in the placing of a printer below the conveyor, it must be able to operate thru the plane of the conveyor, it must allow the lumber to pass over without interference, and the operation of the printer must continue in spite of the dust, dirt, and sawdust that will fallen it when in such a position. Further, it is an object of the invention to discriminate as to the length of the lumber and to mark it accordingly. Another object of the invention is to devise a printer that will have a printing hammer with a printing head that, when actuated, moves from its home, retracted, or ink position below the conveyor to its printing position above the conveyor to print the end of a piece of lumber.

The above and other mentioned defects of the prior art are remedied and these and other objects of the invention achieved by means of a device adapted to be mounted in fixed position below a takeoff conveyor from the trim saws. Such conveyors are, usually, composed of a series of parallel travelling chains driven in unison but without interconnecting cross bars. Lugs to engage the lumber are secured to the chains, and a set of such lugs are in alignment across the chains and the alignment is normal to the length of the chains. A piece of lumber coming from the saws is engaged by two or more lugs of a set thereof and moved from the saws. All the lumber coming from the saws has one end of each piece aligned with one end of every other piece so that all the lumber is in one end alignment, even at one end. At the printing station, there is a series of printers in alignment across and below the conveyor. The lumber is cut to length in variations of two feet, so, all but one of the printers are spaced apart at two foot site intervals across the conveyor. One of the printers, the even end site printer, or brand printer, prints the aligned end of each piece of lumber. The other end of each piece of lumber is printed by the printer at the site adjacent the end of the piece away from the even end. This 'latter printer and all the other printers than the brand printer, are called dimension printers because the even end printer is usually used for printing the brand and/or grade on the lumber and the other printers are used to print a dimension or dimensions on the lumber.

line

All of the printers are of the same construction except for the type, or indicia, which each printer impresses on the lumber. Each printer has a body which is fixed with respect to the conveyor frame, track, or supports. The body carries and pivots thereon a print hammer, the head of which holds the printing block and indicia, which hammer is actuated to swing on its pivot by means of a piston rod actuated by a double acting piston and air cylinder. Suitable controls actuate the brand printer, and select and actuate the proper dimension printer, all at the right time. When not in operation, when a piece of lumber is not in proper alignment with the printers, the hammers lie below the plane of the conveyor and do not interfere with the passage thereover of the lumber. Upon actuation, print hammers swing upwardly to strike the ends of a piece of lumber. In its retracted position, the indicia of each printer contacts an ink pad.

A printer such as briefly described above, is hereinafter described in detail and shown in the accompanying drawings, along with a description and a diagrammatic showing of the installation of a series of such printers and their controls with respect to a lumber conveyor and a piece of lumber thereon. In these drawings:

FIGURE 1 is an isometric view, with some parts partially broken away, of a preferred form of a printer embodying the present invention.

FIGURE 2 is an elevational view of the printer of FIGURE 1.

FIGURE 3 is an elevational view showing a modification of the device shown in FIGURES l and 2.

FIGURE 4 is a diagrammatic showing in sectional elevation across a lumber conveyor of an installation of such printers and the controls therefor.

FIGURE 5 is a righthand end view of FIGURE 4.

FIGURE 6 is a detail view, partly in section, of one of the control valves found in FIGURE 4.

Referring to FIGURE 1, this an isometric view, and FIGURE 2 is an elevational view of a printer embodying the present invention. While there may be other forms of the invention, as shown in FIGURE 3, the present showing well illustrates the principles thereof, and is a preferred form thereof. FIGURE 1 shows a printer body ll which has as a part at one end thereof, the right hand end as shown in the figure, extending upward therefrom, and integral therewith, a mounting plate 12. having therethru bolt holes 13 for the reception of bolts which will secure the body to a conveyor frame (not shown in the drawings) or other support means suitably placed. There is a

gusset

14, 15 at each side of the body between the plate 12 and a body bed I6. A pintle 17 has its ends secured in and extends between these gussets. The hearing hub 18 of a print lever 19 rotates on this pintle between the gussets. This lever has a short actuating arm 21, or boss, and a print arm 22, or hammer arm, formed with a slot 23 therein. The outer end, or head 24, of the hammer arm 22 is formed with a print shaft hearing which receives therein a print carrying shaft 26. This shaft extends outboard of both ends of its bearing head '24. The far side end of the print shaft 26 has secured thereto and thereon for rotation therewith, a print block sleeve 27 which has integral therewith a print block 23 carrying on its radially outward face the desired indicia to be printed on the lumber.

The full line position of the print block 28 and the print arm 22 in FIGURES 1 and 2 is the inking position, or retracted position, and the dotted line showing 29 of FIGURE 2 is the printing position of the block and arm. The print sleeve 27 and its print block 28, and the print shaft 26 are rotated between print and ink positions by means of a rack rod 36, the left hand portion of which is square and has thereon rack teeth 31 cooperating with a pinion 32, both of which are on the near side of the printer body 11. The pinion 32 is secured to and on the outboard near end of the print shaft 26 along with and between the sides of a guide 33, or keeper, which is free to turn on the print shaft at each side of the pinion 32. The guide is U-shaped in form and bears against the three smooth sides of the rack portion of the rod, the sides other than the toothed side which is in engagement with the pinion 32, to maintain the teeth of the pinion and the rack in proper mesh. The right hand end of the rack rod is round and slides in a pivot block 34 thru which, and off the center line of the rack, there is a headed journal pin 36 secured in a slot 37 in the near gusset 15. The journal pin is secured in position in the slot by a clamp nut 38 on the threaded end of the pin which is smaller in diameter than the journal portion thereof, and which end extends thru to the far side of the gusset. The juncture of these diameters forms a shoulder which stops the pin against the gusset 15. A stop 39 is secured to or made a part of the rack rod and is located between the pivot block 34 and the guide 33 a distance from the guide so that as the print arm is moved from its ink position to about three-fourths of the Way to its print position, the print shaft 26 and the print block 23 will be rotated 180 degrees with respect to the print arm by the pinion rolling on the rack, and the guide will move to contact the stop 39. A coiled compression spring 41 surrounds the rack between and bears on the stop 39 and the pivot block 34 to bias the rack away from the pivot block. Movement of the rack to the left from the block is limited by a pair of jam, or lock, nuts 42 on the threaded righthand end of the rack rod 30, beyond the block from the spring. The position of the lock nuts 42 on the rack rod may be varied to align the print block or to vary the tension on the rack spring 41. Also, the print block may be aligned by rotating the block and its sleeve relative to the print shaft 26 or by disengaging the rack and pinion for relative movement thereof. Varying the position of the journal pin 36 in its slot 37 varies the extent of rotation of the print block so that it rotates the proper degrees when the print arm moves from its ink to its print position. When the print arm is swung upward and after the guide 33 has contacted its rack stop 39, the print block does not rotate with respect to the arm, and the rack spring 41 is compressed. After printing has taken place, the rack spring serves to start the print arm on its return to its ink position. Once started, gravity completes the return.

The ink position of the print arm 22 is determined by the seat 43 of a bench which is located near the left end of the body bed 16. A leg 44 of the bench is secured to each side of the bed and the seat extends across and above the bed. The near side of the bench seat may have secured thereto a rubber bumper 46 which takes the shock of the return of the print arm head 24 as the print arm returns to ink position. The far side of the bench has secured thereto an ink pad 47 which will be contacted by the indicia of the print block 28 when the print arm is in its ink position. The far end of the bench seat 43 overhangs the far bench leg to provide sufficient support area for the ink pad 47.

The print lever 19 is actuated by means including a double acting air cylinder 51. One end of the cylinder is closed and has an eye 52 secured thereto which is pinned for pivotal movement between two cylinder anchor cars 53 integral with the left end of the bed 16. A piston rod 54 from the piston of the air cylinder 51, has at its outer, righthand, end a square tappet 56 that acts as an extension and an end for the rod. The tappet 56 is adjustably secured to the end of the rod by means of a threaded stud '7 fixed in the tappet and screwed'into the end of the piston rod. A locknut 58 looks the stud against rotation. The tappet 56 rides on the print lever bearing hub 16, and bears against the lever actuating arm 21 when the piston rod 54 and the tappet move out from the cylinder. This outward movement of the tappet from its retracted position, actuates the lever 19 to raise the print arm 22 to printing position. As the print arm approaches the print position, the tappet 56 slides over the top edge of the lever actuating arm 21, but the inertia of the lever is sufiicient to carry the print block 28 and its indicia against the lumber or to carry the print arm 22 against a part of the mounting plate 12 which acts as a stop for the print arm. This overriding of the actuating arm by the tappet when in its extended position, leaves the actuating arm and the print arm, the lever 19, free to return to their ink positions independently of the return movement of the piston rod 54-. The rack spring 41 aids in returning the print arm to its ink position, as previously described.

FIGURE 3 is an elevational view of a modification of the printer shown in FEGURE 1. As the modification relates only to the construction and operation of a mechanism which has been substituted for the rack rod 30 and pinion 32 of FIGURES 1 and 2, some of the details of construction shown in FIGURES 1 and 2. have been omitted from the showing of FIGURE 3. Parts illustrated in FIGURE 3 which are the same as those in FIGURES l and 2 have been given the same reference numerals. The near outboard end of the print shaft 26 has secured thereto, in place of the pinion 3-2, a crank disc 61 having thereon a crank pin 62. Rotation of this crank disc rotates the print block sleeve 27, the print block 28, and the print shaft 26 between ink and print positions. This rotation is accomplished by a resilient link 63 extending between and pivoting on the revolvable crank pin 62 and on a fixed pin 64 secured in the near side of the bed 16. The illustrated position of the fixed pin is below the print lever pintle 17 a distance greater than the crank pin diameter of crank disc 61 and a little to the left of the pintle 17. This is so, and the crank pin in ink and print position is so, that when the print arm moves from ink to print position the resilient link 63 will not have passed across the axis of the crank disc 62 or of the pintle 17. The rotation of the print block is restricted to a few degrees less than to prevent the center line of the link, its line of effort, passing to or over the center of the pintle 17 or of the crank disc 61. To pass to or over such a center would be equivalent to a dead center or toggle link condition. Restriction of the rotation of the print block is achieved by securing a fixed stop 66 on the print arm 22 adjacent to the crank disc 61, and by forming the crank disc with a movable stop 67 to contact the fixed stop. The fixed stop overhangs the near end of the print arm head 24- so as to be contacted by the movable disc stop. The two stops are proportioned circumferentially of the disc so that the rotation of the disc is restricted as desired, as set forth above. In this connection, the stops are arranged so that the indicia face of the print block 28 when in print position is normal to the axis of the print arm 22, and a few degrees off normality when in the ink position and in contact with the ink pad 47.

The link 63 is constructed so that it will be resilient so that the

stops

66, 67 will be in full contact in ink and print positions without the need for extreme accuracy in setting the link length, and in locating the position of the link fixed pin 64. The link is composed of two parallel and spaced apart

rods

68, 69 guided on each other by means of three spaced apart guides 71, 72, 73 for longitudinal movement relative to each other. The two rods are biased against such relative movement in either direction from a balanced condition and position by means of a pair of

springs

74, 75 which surround the lower rod 69, the one connected to the crank pin 62. Each spring is between two of the spaced apart guides. The outer guides 71, 73 are fixed to the upper rod 68 and the lower rod slides in these outer guides. The middle guide 72 is fixed to the lower rod 69, extends between the

springs

74, 75, and the upper rod slides in this middle guide 72.

Nuts 77 threaded on the rods fix the guides in position on the rods and permit the guides to be located and spaced as required.

When the resilient link 63 and the print arm 22 are away from their ink and print positions, say a fifth of the distance between ink and print, the pressure of the two springs '74, 75 against each other, is balanced. Movement of the arm from this balanced spring region to either print or ink position will cause one or the other spring to be compressed. In the ink position, the lower spring '75 is compressed, while in the print position the upper spring 74 is compressed. This use of the springs holds the

stops

66, 67 .in firm contact. Also, with this arrangement, the stops are in contact and the print block in position for ink or print before the print arm 22 reaches either of such positions.

Raising the print arm 22 from its ink position, first, relaxes the lower spring 75 until the two springs are balanced, then the

stops

66, 67 separate, and as the arm progresses from its ink position, the link 63, due to its position, pulls on the crank pin 62 to rotate the print block to its print position where the stops again come into contact. Then, as the print arm 22 approaches the print position, the upper spring 74 is compressed. The upper spring, also, serves as a return spring to start the print arm on its return to ink position. The actuation of the print arm in FIGURE 2. is the same as for the actuation in FIGURE 1. In the print position, the radial face of the block and the indicia thereon will be normal to the length of the print arm and in position to contact a piece of properly positioned lumber. The mounting plate 12 may serve as a stop for the print arm when it moves slightly beyond the print position.

Two air hoses, 80, 81 are in communication with and supply air to and exhaust it from the air cylinder 51. One of the hoses supplies air to move the cylinder piston, and its rod 54 and tappet 56 from the cylinder to its extended position so as to move the lever 19 with its print arm 22 to print position, and the other hose supplies air to move the piston assembly back to its retracted position. As one hose supplies air to one side of the piston, the other hose exhausts air from the other side of the piston.

The controls for the passage of air to and from a series of printers associated with a lumber conveyor are schematically shown in the remaining figures of the drawings.

The schematic showing in FIGURE 4 of the controls for an installation at a printing station of the printers of either FIGURE 1 or FIGURE 3 in association with a lumber conveyor, shows a series of such printers as represented by a series of

boxes

82, 83, 84, 85, 86, each having as a part thereof a print hammer 22 and a print block 2% shown in either their ink or print positions. These printers are arranged and spaced apart transversely of a lumber conveyor shown in transverse elevational section as represented by two conveyor chains 88', 89 carrying thereacross a piece of lumber 90 at the print station in position to be printed on its ends by the indicia carried by the

printers

84, 86. Lugs 91 on each chain are in alignment transversely of the conveyor and serve to align pieces of lumber with their lengths transverse the conveyor, parallel to the elevational section of the view. The right hand end 92, the even end, of each piece of lumber, as in the drawing, is always in the same position when the lumber is at the printing station, and the right hand edge of the conveyor is the even side of the conveyor. Also, the printer 86 at the even edge always prints at each printing operation. This printer usually prints the mill trademark and the grademark, and may be called the grade printer, while the other printers print the lumber dimensions, and may be called dimension printers, as they are spaced across the conveyor at two foot intervals except between the grade printer and the first dimension printer. Each printer has its air hoses S0, 81 connected to and in communication with a solenoid actuated halanced air control valve 93, or spool valve, such as shown in detail in FIGURE 6. Air is supplied under pressure to all of the control valves by means of a header 94. Each solenoid 96 associated with one of the control valves d3 has a lead 7 connected to a common power buss 98. This lead 97 and its buss may be considered to be the negative, or ground, lead and buss. The other lead 99 connected to each solenoid may be considered to be the positive lead and is connected to a common positive buss 161 having therein and therealong a series of

switches

102, 103, 104, 105, 106. There are as many of these switches as there are printers. For each printer added, there is added another switch. However, other switches may be added for other purposes, and all of the switches are not of the same type or construction. The two

switches

105, 106 adjacent the even side of the conveyor are single pole heavy duty switches, preferably of the mercury type. These switches may be called the grade switches as when they are closed the grade printer 86 is actuated. The first of these grade switches contacted by a piece of lumber, as seen in FIGURE 5, may be called the grade break switch 105 as its function is to break the positive buss circuit. The other grade switch may be called the make grade switch 196 as its function is to make the positive buss circuit. Also, the grade switches may be called the make and break switches, collectively or respectively. The rest of the switches may be called dimension switches 102 103, 104, and these switches are of the double throw two point make type, or they may be single pole double throw switches, and need not be of as heavy service type as the grade switches, as these dimension switches neither make nor break a circuit under load. Each of the switches has an operating finger 103 which is extended from its switch so as to be in a position to be contacted and moved to operate its switch upon the passage of a piece of lumber thru the printing station. The grade switches may be considered to have open and closed positions which open and close the positive buss. The grade switches are open when a piece of lumber is absent from the printing station, when their control fingers 108 are raised, up, and closed when lumber is present at the printing station, when their control fingers are down. Each dimension switch may be considered to have an up, or operate, position when its control finger is up, no piece of lumber present to hold it down, and a down, or pass, position when its control finger is down, a pieceof lumber present to hold it down.

When a dimension switch is up it closes operate contacts,

169, in a solenoid positive lead 99, and when it is down it bridges pass contacts 110 in the positive buss 101. All of the switch operating fingers 1% are in up position when a piece of lumber is absent from the printing station, and all of the printers are in ink position with their actuating piston rods retracted.

Under the conditions shown in FIGURES 4 and 5, the piece of lumber is centered at the print station. In approaching the print station, the forward edge of the lumber traveling in the direction of the arrow associated with the conveyor chain 89 in FIGURE 5, first contacts the operating finger of the break grade switch to close this switch. Next, further travel of the lumber contacts the operating fingers of one or more of the dimensions switches, in this showing the finger of the first 11M- from the right, to move the switch from its operate contacts 109 to its pass contacts 110 to thereby open the positive lead 99 to the solenoid 96 associated with the first from the right dimension printer 85 to prevent its operating, and to thereby close the positive buss 101 to the next dimension switch 103 whose operating finger is up as it is beyond the end of the piece of lumber 90. The dimension switch being in the up position will have its operating contacts 109 closed to make the circuit thru the solenoid of the printer 84 and to ground. The pass contacts 110 of the switch 103 are open so that the circuit to the solenoids of the

other printers

82, 83 can not be made. At this time in the movement of the piece of lumber, it only requires the closing of the make grade switch 106 to complete the circuits to the dimension printer 34 and the grade printer 36; and, upon the closing of the make switch, only these two printers will operate. The make switch 106 is so positioned in the direction of conveyor travel that it will close at the time that the piece of lumber 90 is centered at the print station. Upon the closing of the make switch, the circuits thru the solenoids of the grade printer 86 and the dimension printer 84 are completed. Each such solenoid then operates to actuate its associated air valve 93 to deliver air to each of the air cylinders 51 of such printers to cause their print arms to swing to print position to thereby print the desired indicia on the ends of the piece of lumber at the printing station. The alignment of the printers at the print station is such that the indicia impressed on the lumber is centered on the piece with respect to the edges thereof. The operating finger of the make switch 106 is movable, as shown by the double arrow 111, in the direction of travel of the conveyor so that it may be placed along the conveyor at a position where it will operate the printers when the piece of lumber has its longitudinal axis aligned with the printers. This position of the make switch operating finger is adjusted for lumber of various widths. Further movement of the piece of lumber releases the operating finger of the grade break switch 105 to allow this switch to open and to open the positive buss 101. This releases the operated solenoids and supplies air to the printers to effect return of the printer piston rods to their retracted positions.

If all the dimension switches but the first from the left switch 102 are in their down positions to close their pass contacts 110, then when this first dimension switch 102 from the left is in its up position closing its operate contacts 109, the second from the left printer 83, operates and when in its down position closing its pass contacts 110, the first from the left printer 82 operates. Thus this switch when in its pass position not only closes the positive buss 101 to bypass the second from the left printer 83 but determines the actuation of the first from the left printer 82.

Each of the print blocks 28 of the dimension printers carries indicia different from that of the other blocks, and each such indicia is related to the position of the printer with respect to the conveyor and the lumber at the printing station so that the indicia printed thereby on the end of a piece of lumber will give the length of that piece.

FIGURE 6 is an elevational view, partly in section, of one of the air control valves 93 and its operating solenoid 96. The air valve is of the balanced type, and, in particular, a spool valve. The valve has a cylindrical casing 112. In the casing, and adapted for movement longitudinally thereof, is a cylindrical valve spool body 113 having therearound four spaced apart seal rings 114, or heads. The rings and the body make what may be called the valve spool. This spool is moved axially of the valve casing by means of a rod 116 and a spring 117 surrounding the rod, both under the control of the solenoid $6, the details of which are not shown. The spring serves to return the spool to its retracted position, that shown, upon opening of the circuit lead 99 of the solenoid after movement of the spool by the solenoid thru the rod 116. The air header 94- is connected to the interior of each of the valve casings thru a port 118 at the mid part thereof, and spaced equally from the midpart of the casing are

ports

120, 121 to which are connected the

air hoses

80, 81 leading to the associated printer. The casing is provided with vent ports 122, 123 for the venting of the

hoses

80, 81, and a port 124 for venting the end of the casing away from the solenoid. The valve is shown with the spool in its unactuated, or retracted,

position, the solenoid is not carrying current. In this position air passes from the air supply header 94 to the hose 81 which will retract the piston rod of the associated printer and hold it in retracted position. Air from the other hose is vented thru its associated vent port 122. Upon actuation of the solenoid, the spool moves to deliver air to the actuating hose 80 to actuate the associated printer, and to vent air from the retracting hose 81. When the solenoid circuit is opened, the spring 117 returns the spool to its retracted position.

From the above description, the operation of the disclosed mechanisms should be apparent. Lumber from the trim saws of a mill is cut to standard lengths, usually varying by two feet. All such lumber approaches the print station with one end at the even side of the conveyor 88-89 in position to be printed by the grade printer 86. When a piece of lumber is centered at the print station, all of the switch operating fingers 108 below the piece have been depressed, the switch having been actuated to close before the operation of the dimension switches, and the make switch 106 being the last one to close and closing as the piece centers at the station. The operation of these switches complete circuits which cause the grade printer 86 to print the even end of the lumber and which cause the dimension printer adjacent the uneven end of the lumber to print, such as the printer 84 shown in print position. Movement of the piece of lumber from being centered at the print station, opens the break switch 105 to break the circuits controlling the printers. Opening the circuits deenergizes the solenoids related to the printers which have just printed, which returns their piston rods 54 to retracted position in readiness to again operate their printers. Further movement of the piece of lumber from the print station, releases the depressed fingers of the make switch 106 to place all of the fingers and their switches in position to sense and be actuated by the next piece of lumber brought to the print station by the conveyor. The dimension switches controlling the dimension printers are never operated under load. Thus, only the make 106 and the break 105 switches need to be heavy duty switches, and switch maintenance will be largely confined to these two switches. The circuit is a simple one with a few switches and little wiring. Movement of the operating finger of the make switch 106 along the conveyor as indicated by the double arrow 111, will adjust the time of operation of the printers with respect to the width of a piece of lumber so that the printing will take place when the piece is centered at the printing station.

Operation of each of the printers is under the control of its associated air control valve 93, operated by the solenoid 06 incorporated therewith and energized by the above described circuits. Each printers print arm moves .to print position when air is supplied to the air cylinder thru the operating air hose 80. This forces the piston rod 54 against the print lever actuating arm 21 to swing the print arm 22 of the lever 19 into print position. Movement of the print arm from ink to print position rotates the print block 28 and the indicia thereon from ink to print position under the control of either the rack and pinion mechanism shown in FIGURES l and 2 or the resilient link shown in FIGURE 3. The piston rod 54 disengages from the lever actuating arm 21 as the print arm approaches the print position so that the inertia of the lever carries the print block against the lumber. This disengagement allows the piston rod tappet 56 to override the actuating arm 21, and allows the actuating arm to cam under the tappet and to return to ink position before the piston rod is retracted upon the opening of the break switch 105. The print block 28 is secured to its shaft outboard of the print arm head 24 so that it may be easily removed for replacement either because of wear or to change the indicia to be printed on the lumber.

Having thus described my invention, its construction and operation, I claim:

1. A printer adapted to print the ends of lumber moving on a conveyor, comprising: a printer bed adapted to be secured in fixed relation to such conveyor, a print lever, a pintle secured to said bed and pivoting said lever for swinging movement thereon, said lever having a pivot hub about said pintle and extending there-from an actuating arm and a print arm, a fluid actuated means arranged between and in engagement with said actuating arm and said bed for the actuation of said lever and its arms about said pintle from an ink position to a print position, said print arm having a head removed from said hub, a print shaft journaled in the head of said print arm, a print block having pivotal movement on said print shaft and having indicia on a face of said block tangential to such blocks pivotal movement, and mechanism acting so that upon actuation of said print arm from ink to print position said mechanism will cause rotation of said shaft and print block with respect to said print arm, said mechanism including linking means extending between and in engagement with said shaft and bed, said mechanism being constructed to have lost motion in causing the rotation of said print block, having stop means limiting such lost motion, and having spring means biasing out said lost motion by movement of a part of said mechanism against said stop means.

2. The combination of claim 1 in which said linking means includes a pinion secured to said shaft and a rack rod having a rack in engagement with said pinion and pivoting on said bed,

3. The combination of claim 1 in which said linking means includes a crank pin secured to said shaft, and said spring means is a resilient link pivoted at one end to said pin and at the other end to said bed whereby said resilient link biases out said lost motion by movement of a part of said mechanism against said stop means.

4. The combination of claim 2 in which said stop means is secured to said rack rod for movement therewith, and in which said spring means surrounds said rod and bears against said stop means.

5. A printer adapted to print the ends of lumber moving on a conveyor, comprising: a printer bed adapted to be secured in fixed relation to such conveyor, a print lever, a pintle secured to said bed and pivoting said lever for swinging movement thereon, said lever having a pivot hub about said pintle and extending therefrom an actuating arm and a print arm, a fluid actuated means arranged between and in engagement with said actuating arm and said bed for the actuation of said lever and its arms about said pintle from an ink position to a print position, said print arm having a head removed from said hub, 21

print shaft journaled in the head of said print arm, a print block having pivotal movement on said print shaft and having indicia on a face of said block tangential to such blocks pivotal movement, and mechanism acting so that upon actuation of said print arm from ink to print position said mechanism will cause rotation of said shaft and print block with respect to said print arm, said mechanism including linking means extending between and in engagement with said shaft and bed; said fluid actuated means including a pivoted piston rod tappet which rides on said pivot hub, moves said actuating arm, and overrides said actuating arm when said arm is in print position so that said actuating arm may cam upward said tappet about its pivot to allow said lever to return to ink position independently of movement of said tappet.

6. The combination of a lumber conveyor having means for moving elongated pieces of lumber in a direction transverse to such elongation; and a lumber printer lo cated below such conveyor, said printer having a print arm and printing indicia carried thereby, said print arm adapted to swing upward to contact and print an end of a piece of lumber carrier by said conveyor, and for said arm a pintle about which said arm swings, said pintle arranged with its length parallel to such direction; said means for moving lumber including a plurality of spaced apart conveyor chains arranged with their lengths parallel to such direction, and a portion of said arm adapted to move thru the plane of said chains whereby such indicia may contact an end of such a piece of lumber; and means for actuating said print arm, and control means controlling said means for actuating, said control means including fingers in the path of such pieces as they are moved by said conveyor, whereby actuation of one of said fingers by such a piece of lumber will cause actuation of said control means and thereby actuation of said actuating means and said arm to eiiect a printing of such a piece, and whereby actuation of another of said fingers by such a piece of lumber will cause deactivation of said control means and thereby readying said control means for further actuation of said actuating means.

References Cited in the tile of this patent UNITED STATES PATENTS 190,754 Hall May 15, 1877 663,048 Sleeper Dec. 4, 1900 1,189,747 Smith July 4, 1916 1,262,826 Mitchell Apr. 16, 1918 1,863,229 McDonough June 14, 1932 1,875,278 Tanner Aug. 30, 1932 2,559,455 Meyer July 3, 1951 2,740,351 Anderson Apr. 3, 1956 2,748,695 Whitecar June 5, 1956