US1806166A - Grading machine - Google Patents

Description

y 1931. J. w. JOHNSTON GRADING MACHINE Filed Feb'. 4, 1929 6 Sheets-Sheet l H lm 1767 Zia? May 19, 1931.

J. w. JOHNSTON GRADING MACHINE Filed Feb. 4, 1929 6 Sheets-Sheet 3 6 Sheets-Sheet 4 I. y h a. j mm 00 I. |izil -I RN Hu rm? U W m May 19, 1931. .1. w. JOHNSTON GRADING MACHINE Fil'ed Feb. 1929 May 1 31-. J. w. JOHNSTON GRADING MACHINE Filed Feb. 4, 1929 6 Sheets-Sheet 5 May 19, 1931.

J. W. JOHNSTON GRADING MACHINE Filed Feb. 4, 1929 GSheets-Sheet 6 lllllll/ Patented May 19, 1931 terri r JAMEs w. JOHNSTON, or MANCHESTER, NEW AMPSHIRE, .AssrCNoB. To LACENE MANUFACTURING COMPANY, or MANCHESTER, NnwnA PsnTnE, A CORPORATION OF MAINE GRADING MACHINE Applicationfiled February 4, 1929. Serial No. 337,245.

This invention relates to grading machines of the kind which grade died-out pieces of leather such as cut soles, taps,.heel-lifts, counters and other blanks in accordance with the thickness of the thinnest spot as deter mined by the detector. The invention cone sists in certain improvements upon the wellknown grading machines covered by a num? ber of patents to Elmer P. Nichols and by the patents and pending applications of Leander A. Cogswell. These: improvements relate particularly to the mechanism for guiding the blank as it is fed to the machine, the mechanism for feeding and propelling the blanks through the machine and the mechanism for controlling the starting of the preservation of measurements as determined by the detecting mechanism for transmission to the grading mechanism.

lVhile the invention is of more general application, itis particularly designed for ap-. plication to a grading machine of the general type illustrated in the Nichols Patent No. i .130,321, dated .March '2, 1915, andby way of illustration, but not of limitation, I shall therefore describe the invention in connection with and asembodied in a machine of thattype.

In the accompanying drawings:

Fig. 1 is a plan view, partly in section, of a grading machine embodying the present im provements; a

Fig. 2 is a side elevation of that'part of the machine which is at the rear of a vertical transverse plane indicated by line .r-w;

ig. 3 is a side elevation of that part of the machine which is forward of the line Fig. 4: is a central, vertical, longitudinal section of the machine shown in Figs. 1, 2 and 3;

Fig. 5 is a plan view. on an enlarged scale, partly in section, of the front end of the machine;

Fig. 6 is a side elevation on an enlarged scale, partly in section and partly broken away, of new tripping mechanism and other parts of the mechanism shown in Fig. 5;

Fig. 7 is a detail in section on line 7-7 of Fig. 6; and

Fig. 8 is a detail of the latch, hereinafter described, associated with the new mechanism for guiding the blanks into themachine.

As the illustrated machine as a whole is substantially similar in purpose, construction and operation to said well-known Nichols and Cogswell grading machines, particularly that shown in said Nichols Patent 1,130,321, it will not be necessary to describe it in all of its details butonly to give such general description as will serve to make clear the improvementswhich constitute the subject matter of this invention. 1 i

Leather blanks such as soles, taps, heellifts, counters, etc. used in the manufacture of shoes, are customarily graded in accordance with the thickness in irons of the thinnest spot of the blank or ofsomeqselected portion of the blank. Grading machines of the kind to which the present invention relates are constructed and arranged to measure and determine the grade of successive blanks of stock fedthrough the machine by afeeling'or detecting operation and then to grade the several blanks in accordance with the thickness of-the thinnest spot so determined by the detaching mechanism. There are various kindsof grading operations'performed by various species of grading mechanism. Theterm grading mechanism is ageneric term, established in this art, and includes devices for stamping or marking each blank with its grade number, evening or skiving the blank as a whole down to the grade or thickness of its thinnest spot, indicating on a visual indicator the grades of the several blanks and sorting or distributing the blanks in accordance with their grades. Two or more species of grading mechanism may be and usually are contained in one-machine and in the Nichols machine selected for illustration there are included mechanism for skiving or evening the blanks and mechanism for stamping ormarking the blanks in accordance with their grades. It will be understood, however, that the present improvements are not restricted to any specific kind of grading mechanism since they are chiefly concerned not with the mechanisms for unimately grading the blanks but with devices associated with the detecting means for guiding the blanks to the detecting means, feeding the blanks away from the detecting means and thence through the machine toward the grading mechanism, and starting the transmission to the grading mechanism of the measurements determined by the detectlng means.

Referring to the drawings 10 .is the main frame of the machine and His a continuously rotating main driving shaft journaled 1n bearings in the machine frame. Atone side of the frame the shaft 11 is provid'ed witli the usual driving pulley and clutch mechanism and at the other side of the framethe shaft 11 carries a pinion 12, which Operates through an intermediate gear v13 to drive gear 14 fast on shaft 15 of the upper feeding and detecting roll 16. The shaft 15 is journaled in boxes 19 adjustably mounted in vertical ways 20 on the frame inthe usual man'- ner. The lower detecting and feeding roll 17 cooperates with the upper roll 16 to feed and measure the blanks and is carried by a shaft 18 journaled in two boxes 19 mounted to slide Vertically in ways 20. The rolls 16 and 17 are geared together as usual. Directly below roll 17 a cross bar 21 is fixed at its ends to the under sides of boxes 19. -The cross bar 21, and consequently the-roll 17 is normally pressed upward in the usual manner by a pair of bell-crank levers 22, whose depending arms are connected by a'spring 22*. "The up and down measuring movements of the detecting and feeding roll 17 are trans-v mitted to the detecting mechanisms at'the other; end of the machine through setting mechanism, which includes the usual lever 23 pivoted to the machine frame at 24 below the cross bar 21, having'at its free enda gear segment which meshes --w'ith' gear segment 25 faston rock shaft 26. Therock shaft 26 constitutes the setting shaft from which the measurements determined by the detecting roll are transmitted to the ad ustable grading mechanism. in the usual way as more fully explained in said Nichols patent." The'cross bar 21' is' connected to lever 23 by two'vertical posts 28, fixed as usual to crossbar 21 and extending loosely through holesin lever 23; Stop nuts 27 are-screwed onto the posts 28 below the lever and spring 27 between the lever 23 and the-cross bar 21 'yieldingly holdsthe lever against stop nuts 27. The foregoing parts, and other associated detailsnot herein shown, are substantially 'as shown in said Nichols Patent 1,130,321, to which reference is made for fuller description. I

The lower detecting roll 17 is made in'two sections, as shown in Fig. 5, separated at the middle to provide 'an annular groove throughwhich runs the upper stretch of a flexible, endless, feeding belt 29 mounted upon and driven by a'driven' pulley 30 at en through chain 34 by sprocket wheel 35 fast on a stub shaft 36, journaled in a bearing block 37. The stub shaft 36 also carries a gear 38 which is continuously driven by pin ion 12 on main driving shaft 11- Through the connections described the detecting and feedingroll 17 and the endless belt 29 are driven by the main shaft 11 at the same surface speed and in the same direction as indi cated by arrows in Fig. et. The idle pulley 31' is journaledon'a bracket 3 9 held in position on the frameof the machine by'two screws 40 extending through slots in the bed plate. Bracket 39 may be adjusted forward andback by means of a threaded stem 41 screwed into a threaded socket on-bracket 39 and extending forwardly therefrom to the front of the machine where it is provided with a head 42, which serves as an abutment for one end of a coil spring 43, surrounding the stem 41' and'bearingat its opposite end against an abutment lug -44 on abracket or shelf"83attached to the machine frame 10. The spring 43 serves at all times to hold the endless belt 29-.taut: I

Heretofore grading machines of this kind have been equipped with an endless chain for feeding and propelling the'blanks from the detecting rolls to the grading mechanism. Such chains have been mounted on sprockets located in thespace between the detecting rolls'and the grading mechanism so that it was notuntil the blankha'd passed through the detecting'rolls and far enough beyond to engage the 'sprocketchains that the chain took up and carried on a forward feeding of the blank through the machine. In the pres ent construction it will be observed thatthe feeding belt 29 passes over a pulley 31 in front of the detecting rolls and-consequently the beltextends forward of the detecting rolls with the result that the operative reach of the feeding beltis available for theentire distance forward to and even beyond the de tecting rolls; 7

Moreover, as sprocket chain afford substantiallyno 'frictionalengagement with the leather blanks it has been necessary and has been the practice to provide the chains with spurs or prongs to penetrate the surface of the blanks sufliciently to prevent slipping and to propel the blanks through the machine. Excepting for a certain amount of disfigurement of the blanks the use of spurs 0n the feeding chains wasnot particularly objectionable when operating upon relatively thick, stiff material such as outer soles. When operating, however, upon relatively light, thin and 'flexible blanks the use of prongs, spikes or spurs on the feedingchain is objectionable for a number of reasons. The perforation and disfigurement of a thin blank by the spurs is much more serious than in a thick heavy blank. As the spurs are necessarily placed some distance apart on the chain links they engage the blank only at more or less widely separated points, sometimes at only one or two points, with the result that the blank may swing sidewise out of its proper alignment; and, most objectionable of all, the engagement of a thin flexible blank by the spurs only at isolated and separated points sometimes causes it to buckle or crumple instead of being fed flat and smooth through the machine. With the present feeding mechanism the conveyor is in the form of an endless belt 29 made of leather or other suitable fabric with a friction-gripping, working surface which engages and frictionally grips the blank throughout its entire length and so holds the same against buckling or being otherwise.

displaced and at the same time avoids any perforation or disfigurement of the blank whatever. The blank is supported on its upper side and held down against the belt by a presser shoe 47, hereafter described. The mechanism will handle thick and heavy blanks equally well. 7

The frame of the machine includes a bed plate 44 formed upon its top side with a groove 45 through which the upper stretch of the belt 29 passes and by which this stretch of the belt is supported. In front of the feeding and detecting rolls is another bed plate 46 to the under side of which the bracket 39 is secured.

Directly above the top stretch of the belt 29 and parallel thereto is a long presser shoe 47, to the ends of which are pivoted two ver-. tical stems or posts 48 and d9, the upper ends of which pass loosely through holes provided in brackets 50 and 51 mounted on the machine frame. top nuts 52 are screwed on the posts 48 and 49 above the supporting brackets to limit downward movements of the posts and shoe 47. Between each of the rackets 50, 51 and the shoe eli are coil springs 53 which yieldingly urge the shoe L7 downward toward belt 29. The under side of shoe-f7 is smoothly polished to afford an anti-friction, sliding surface forthe blanks being fed through the machine, so as to ofier the least possible friction resistance.

When a sole or other blank is to bepassed through the machine it is fed in either by hand or by feeding mechanism upon the bed plate 46 and beneath the usual gate 54 until it is engaged by the nip of the feeding and detecting rolls 16 and 17. As soon as the blank is gripped by these two rolls it is propelled forward thereby into position between the presser shoe l and the traveling belt 29 so that thereafter until therear or following end of the blank leaves the'rolls 16 and 17 the blank is moved forward by the joint action 'of the rolls and the belt. After the rear or following end of the blank leaves rolls 16 and 17 the belt 29 by frictional engagement with the blank continues to propel it forward toward and past the grading mechanism at the delivery end of the machine. When the leading end of the blank stood, has been previously automaticallyadjusted to correspond to the grade measurement as determined by the detecting rolls, by the usual well-known mechanism employed in grade marking machines of this type, and more fully described vin said Nichols patents to which reference maybe had for further details. Parts only of the mechanism are illustrated herein, including the double ratchet wheel 58 fixed on shaft 26. Pawls 59 and 60 cooperate with the opposed ratchet sectors of wheel 58, the teeth of one ratchet facing in one direction and the teeth of the other ratchet facing in the other direction. These two pawls'function as usual. The pawl 60 is connected as usual by link 61 with the gate 54 at the front or entrance end of the machine' So long as the gate is heldelevated either by the blank or by mechanism in the machine, the pawl 60 is held retracted and inactive. The pawl 59 is moved by gravity into engagement with its ratchet, on wheel 58 and is made with a tail piece 63 normally helc depressed, with the pawl inactive, by a vertically movable gravity plunger 64. As usual-in grading machines of this type, and as will be understood by refer ence to said Nichols Patent No. 1,130,321, when the pawl 59 isin engagement with its ratchet the wheel 58 and its rock shaft 26 will be free to turn in response to successive thinner spots as determined by the detecting mechanism, but not in the opposite direction, thus preserving the thinnest measurement of the blank for transmission to the grading mechanism. When both pawls 59 and 60 are in engagement with their respective ratchets the shaft 26 will be locked against movement in either direction.

Heretofore the gravity plunger 64 has been lifted to set pawl 59 by the lifting of trip arm (hereinafter described) when the forward or lea-ding end of the blank reaches and lifts the trip member carried by said trip arm 70. It is one of the features of my present invention to operate the gravity plunger 64 independently of the trip arm by means of a lever 65 fulcrumed at 66 on a bracket supported by the frame of the machine. One end of the lever 65 is pivoted at one end to the gravity plunger 64 and the other end, extendi ngin the opposite direction from the fulcrum, is cooperatively disposed with relation to a cam 67 fast on one end of a short horizontal spindle 68 journaled in hearings on bracket 51 close to the upper roll 16. The spindle 68 extends inwardly to a point over the path of the blanks and has fixed to it at that point a pair of depending trip fingers 69, occupy ing positions at opposite sides of the forward end of the shoe 47 and closely adjacent thereto. The fingers 69 extend inward close to the nip of the rolls 16, 17, so that as the blank emerges from between the rolls it immediately engages the trips 69 swinging them away from the rolls and thereby turning shaft 68 and cam 67. The cam 67 swings lever 65 on its fulcrum thereby lifting the gravity plunger 64 and permitting pawl 59 to engage its ratchet, thus rendering the setting mechanism operative to preserve the measurement of the thinnest spot as determined by the detective rolls. Pawl 59 remains in engagement with its ratchet until the rear or following end of the blank passes the trip fingers 69, whereupon the gravity plunger 64 falls to its normal position where it rests on top of the frame 10 with the pawl 59 out of action and the trip fingers 69 restored to their normal position shown in the drawings; but meanwhile the blank will have left rolls 16, 17 and the pawl 60 will have been locked to prevent ratchet wheel 58 and setting shaft 26 from moving in the direction to record further upward motions of roll 17 The return movement of'the trip fingers 69 is brought about by the fall of the gravity plunger 64 acting through lever 65 to restore the cam 67 and shaft 68 to the position shown in the drawings without the assistance of a spring. 'This automatic restoration is made possible by the fact that the cam 67 is rotated by the blank less than 90 and functions as a crank arm when the blank moves out of engagement with the trip fingers '69.

'Among the advantages of'this new tripping mechanism for setting pawl 59 and starting the transmission of the thinness measurements to the grading mechanism, is the fact that the action of the trip fingers 69, 69 is exceedingly light and sensitive as compared to the action of the weighted rod 70 heretofore employed, and that the trip may be actuated immediately upon the emergence of the advance end of the blank from rolls 16 and 17 and the measuring action therefore may be started sooner. The very light action of the trip 69 is of great importance in operating upon thin, light blanks, which would be likely to curl or crumple, and so both damage the blanks -and clog the'ma chine, if the trip should offer serious resist ance to their passage. The non-curling effect of the light acting tripis assisted by the fact that the trip fingers 69, 69 extend closely alongside the presser shoe 47 which extends well forward toward the trip of the rolls with its tip received in grooves in the upper. roll 16, so that the presser shoe promptly comes into action to help hold the blanks fiat and smooth while the trip fingers 69 are being actuated.

The effective measuring or detecting of a blank by the detecting rolls starts when the advance or leading end of the blank emerges from the detecting rolls and operates the trip fingers 69 to set the thinness measuring pawl 59, and stops when the gate 54 falls to the table after the passage of the rear or following end of the blank, thereby setting pawl 60 into engagement with .its ratchet. At this stage therefore the ratchet wheel 58, and'its shaft 26, from which the detected measurements are transmitted to a grading mechanism, are locked against further movement in either direction. hen the following end of the blank passes out from under the trip fingers 69 the gravity plunger 64 will be free to drop as already explained,- thereby unlocking pawl 59 but leaving pawl 60 still locked until the gate 54 is again lifted.

The mechanism for operating the gate'is controlled by the passing blanks, and consists of the trip arm 70, fixed at one end to a rock shaft 71 and thence extending toward the rear of the machine over the pathv of the blanks. Near its free end the arm 70 carries an adjustable weight 77, provided with a set screw, and a depending bracket 78, also provided with a set screw. The bracket 78 is made at its lower end with a bearing in which is journaled an axle 79 carrying two trip wheels and 81, one at each side of the bracket. Wheels 80 and 81 normally rest in the groove 45 of the bed plate, one at each side of the presser shoe 47, directly in the path of the blanks. The gate 54 is normally held in open or elevated position (with pawl 60 disengaged) by the weight of arm 70, and the parts carrier by it, acting through rock shaft 71, the short arm 72 fixed to rock shaft 71, and the lever 7 3. The lever 7 3 is fulcrumed at 74 on the bracket 51. One end of lever 7 3 engages underneath arm 72, and the other end is connected to gate 54 by a link 75, which has a pin and slot connection at its upper end and a pivot pin 76 connecting its lower end to the gate. construction is substantially as shown in the Cogswell Patent No. 1,366,889, dated January 25, 1921. I

The trip bracket 78 may be adjusted on rod 70 according to the length of the blanks being operated upon and the desired timin g of the operation of the gate. Preferably it is so ad- This gate opening justed that the advance or leading end of the blank engages the trip rolls 80 and 81 just as the following end of the blank approaches the rolls 16 and 17, thus liftingthe rod 7 O and lowering the gate before the blank passes out from between rolls 16 and 17. If the blank has already passed from under the gate the gate will drop to the table and set pawl. 60 into locking position; if the blank is still under the gate when rod is lifted the gate will fall until its foot 62 rests on top of the blank, where it may be arrested by reason of the slot and pin connection of link 75, in which case pawl 60 will still be held disengaged, but as soon as the blank passes out from under foot 62 the gate will fall to the table and lock pawl 60. .When thus locked, the pawl 60 will remain locked so long as the blank supports the trip wheels and 81. This enables the blank to reach and be operated on by the grading mechanism, for example the stamping wheel 57, while the grade setting mechanism,'including the wheel 58 and setting shaft 26, remain locked by pawl 60 in accordance'with the measurement as determined by the detecting rolls. When the following end of the blank'passes out from.

under the trip wheels 80, 81, the weight of the parts carried by .rod70 will swing the latter downward, thereby lifting the gate 54 and unlocking pawl 60 and so restoring the machine to position for receiving another blank. The unlocking of pawl 60 will permit the detecting roll 17 to be lifted to the limit of its upward movement by spring 22*. Thus it will be seen that the automatic opening of the gate, controlled by the blank through wheels 80 and 81, and the unlocking of ratchet wheel 58 and setting shaft 26, may be delayed and timed to occur after the following end of the blank has passed the detecting rolls 16 and 17, and after the leading end of blank has been acted upon by the type wheel 57 or by other grading devices if others are used. Also the closing of the gate by the advance end of the blank may be accomplished independently of the setting of pawl 59 and may be delayed until the blank has nearly passed through rolls 16 and 17.

The graded blank is discharged from the machine down an incline82 at the rear end of the machine. As already indicated, other usual instruments may be used at the de livery end of the machine, such as skiving and evening devices or other grading mechanisms, ejecting rolls, etc., as already known in the art. i

Many blanks used in shoe making and required to be graded by machines of this kind are crooked or asymmetrical. For example, the median lines drawn from the end of the heel of a cut sole to the shank and from the shank through the ball to the tip of the toe form a pronounced angle with each other. The part of a cut sole which-it is important to grade with accuracy is the forepart and it is therefore desirable that the sole should pass through the machine with the median line of the forepart'parallel and substantially coincident with the median line of the machine, that is, approximately midway between the two sections of the detecting roll 17 This is desirable for the further reason that the area of the forepart of a sole which is mostimportant' to grade with. accuracy is the margin and it is therefore important that one section of the two-part roll 17 should traverse one side of the ball of thesole and the other section the opposite side. For accomplishing this result I have devised an improved guiding and centering device.lo-' cated at the entrance of the machine for guiding and positioning the sol-e properly as it is sent to the rolls 16 and 17. This mechanism includes the bracket or'table 83, fixed rigidly to the frame of the machine, whose top surface in efiect constitutes an eXtension of bed plate 46. The table 83 is formed with a transverse slot 84 within which is a transverse shaft 85, one end of which is 89 form between them a guide channel or trough for the incoming blank, at" all times parallel to the median line of the machine. The shaft 85' is provided with a hand wheel at one end by means of which the shaft may be rotated to shift the slides 88 and the guide plates 89 simultaneously toward and from each other to conform to the ,width of the blanks being graded. Each guide plate 89 has hinged or pivoted to its inner end an angularly adjustable guide plate section 91 made at its top with an upstanding lug 92. The two lugs 92 are held against the outer sides of two abutment arms 93, each of which is part of a bell crank lever 94 mounted upon and threaded to a shaft 95 j ournaled in bearings on the frame. of the machine. The other arm 96 of each bell crank member 94 engages and slides upon the frame of the machine and serves to hold the member 94 from rotating when the shaft 95 is rotated. About half the length of the shaft 95 is formed with a right hand screw thread engaged with one member 94 and the other half is formed with a left hand screw thread engaged with the other member 94. Thus, when, shaft 95 is rotated the two members 94 are simultaneously adjusted toward or from each other.

is accomplished simultaneously and in like degree with the lateral adjustment of the guide plat-es 89 by connecting the shafts 95 and 85 to rotate together. Fixed to one end of shaft 85 is a sprocket Wheel 97 connected by a sprocket chain 98 with a sprocket wheel 99 fixed to one end of shaft 95, said two sprocket Wheels being ofthe same diameter. Accordingly, when shaft 85 is rotated by means of the hand wheel 90 to adjust guides 89 toward and from each other, shaft 95 will be similarly rotated tov adjust members 94 toward and from each other in like manner and to the same extent.

In order to adjust and adapt the guides 89 and 91 to either right hand or left hand soles or other crooked blanks the shaft 85 is made bodily shiftable endwise in both directionswithrespect to the table 83, the collars 100. and 101 serving to limitthe extent 7 of such shifting movement. \Vhen the shaft 85 is in the-position shown in solid. lin in Fig. 5 the main guide members 89, 89, will be offset Slightlyto the right while the angular guide members 91, 91 will be inclined to the left'since their lugs 92will be held in engagement With and fulcrumed on the outer sides of the stationary abutments 93 by-means of a tension spring 102. When the shaft 84: is shifted to the left with the collar 101 against the right hand bearing 86-the guides will be'movedto dotted line position, the main guidesections 89, 89 remaining in parallelism' but ofiset slightly .to the left and the angular guide sections 91, 91 likewise remainingin parallelism but swung to the right, all as shown in dotted lines. In order to hold shaft 85- in either ofits shifted positions a latch 103 (Figs. '5 and 8) is provided on the end of table 83 to engage one side or the other of collar 101. Ifclaim: i 1. A gradingmachine of the kind having detecting mechanism for measuring successive blanks according to thickness, a normally open gate in advance of the detecting mechanism, grading mechanism, setting .mechanism responsive to the detecting mechanism and controlling the grading mechanism and normally inoperative to preserve the grade measurements determined by the detecting mechanism, anda trip in the path'of the blanks for controlling the gate, said trip. being independent ofand in advance of the grading mechanism, including .in combination a second trip in the path of the blanks adapted to be operated by the blanksindependently of the first named trip to render the setting mechanism operative to. preserve said grade measurements.

2. A grading machlne of'the kind having detecting mechanism for measuring successive blanks. according to thickness, a normally open gate in advance of the detecting mechanism, grading I mechanism, .setting mechanism responsive to the detecting inset-1 blanks independently of the first namedtrip to render the setting mechanism operative to preserve said grade measurements before the first named trip isactuated to close the gate. f

3. A grading machine of the kind having detecting mechanism for measuring successivexblanks acordingfito thickness, grading mechanism, setting mechanism responsive to the detecting mechanism and controlling the grading mechanism, a normally open gate in advance of the detecting mechanism, a trip in the path of the'blanks'for controlling the gate, said trip being independent of and in advance of the grading mechanism, and a normally inactive pawl actuated by the gate and cooperating withthe setting mechanism; including in combination a second trip in the path of the blanks and a second normally inactive pawl cooperating with the setting mechanism and actuated by the second trip independently of the first named trip.

1. A grading machine of the kind having detecting mechanism for-measuring successive blanks according to thickness, grading mechanism,'setting mechanism responsive to the detecting mechanism and controlling the grading mechanism, a normally open gate in advance of the detecting mechanism, a trip in the pathof the blanks for controlling the gate, said trip being independent of and in advance of the grading mechanism, and a normally inactive pawl actuatedby the gate and cooperating withjthe' setting -1nechanism; including in combination a second trip in the path of the blanks-in advance of the first named trip and afsecond normally inactive pawl actuated by the second trip, adapted to be operated by'the blanks independently; of the first named trip to render the second pawl active before the first pawl is rendered active by the closing of the gate, and again to renderthe second pawl inactive before'the first pawl is rendered inactive by the opening of the gate. i

5. A grading machine of the kind'having detecting rolls for measuring successive blanks according to thickness and a normal- 1y inactive setting pawl; including, in combination, tripping j mechanism comprising a rock shaft, a trip fingerfixed to the rock shaft and extending close to the nip of the rolls, a gravity plunger to operate the'pawl,

a lever fulcrumed betweentherrock shaft and the gravity plunger and a cam. on therock :shaftto actuate the lever. 3 V I 6. A grading machine of the kind having detecting mechanism for measuring successive blanks according to thickness and grading mechanism responsive to the detecting mechanism, including means for propelling the blanks from the detecting mechanism to the grading mechanism comprising an end less belt having a friction surface adapted frictionally to engage the blanks throughout their whole length and an anti-friction presser shoe adapted to hold the blanks in frictional engagement with the belt.

7. A grading machine of the kind having detecting rolls for measuring successive blanks according to thickness and grading mechanism responsive to the detecting rolls, the lower roll having an annular groove at its middle, including means for propelling the blanks from the detecting rolls to the grading mechanism comprising an endless belt having a friction surface adapted frictionally to engage the blanks, the working stretch of said belt passing through the groove in the lower detecting roll, and an anti-friction presser shoe adapted to hold the blanks in frictional engagement with the belt.

8. A grading machine including feeding and detecting rolls, and means for guiding blanks to said rolls comprising a pair of guide members, each made in two sections, one of which is angularly adj ustable with relation to the other.

9. A grading machine including feeding and detecting rolls, and means for guiding blanks to said rolls comprisin a pair of guide members, each made in two sections, one of which is angularly adjustable with relation to the other, and means to adjust the two angularly adjustable sections simultaneously and in parallelism.

10. A grading machine including feeding and detecting rolls, and means for guiding blanks to said rolls comprising a pair of guide members, each having a main section and an angularly adjustable section hinged thereto, means to shift the two main sections together transversely of the machine, and stationary means on which the hinged sections are fulcrumed, adapted to swing the hinged sections angularly with relation to the main sections when the main sections are so shifted. c

11. A grading machine including feeding and detecting rolls, and means for guiding blanks to said rolls comprising a pair of guide members, each having a main section and an angularly adjustable section hinged thereto, means to shift the two main sections together transversely of the machine, stationary abutments between the hinged sections to hold them in spaced relation, and a spring to hold said sections against the abutments, whereby the hinged sections will be swung angularly with relation to the main section when the main sections are so shifted.

12. A grading machine including feeding and detecting rolls, and means for guiding blanks to said rolls comprising a pair of guide members, each having a main section and an angularly adjustable section hinged thereto, and means to adjust both the main sections and the angularly adjustable sections toward and from each other simultaneously and to like extent, to vary the width of the guideway without varying the angular relation of the sections.

13. A grading machine including feeding and detecting rolls, and means for guiding blanks to said rolls comprising a pair of guide members, each having a main section and an angularly adjustable section hinged thereto, a shaft having oppositely threaded parts adapted to adjust the main sections toward and from each other, members on which the angularly adjustable sections are fulcrumed, a shaft having. oppositely threaded parts adapted to adjust said members, toward and from each other, and means connecting the two shafts for rotating one from the other to cause the main sections and the angularly adjustable sections to move toward and from each other simultaneously and to like extent.

1 1-. A grading machine including feeding and detecting rolls, and means for guiding blanks to said rolls comprising a pair of guide members, each having a main section and an angularly adjustable section hinged thereto, a shaft having oppositely threaded parts adapted to adjust the main sections toward and from each other, abutment members between the angularly adjustable sections to hold them in spaced relation, a spring to hold said sections against the abutment members, a shaft having oppositely threaded parts adapted to adjust said abutment members toward and from each other, and means connecting the two shafts for rotating one from the other to cause the main sections and the angularly adjustable sections to move toward and from each other, simultaneously and to like extent.

Signed by me at Manchester, N. H., this 31st day of January, 1929.

JAMES W. JOHNSTON.

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