US2125295A - Grading machine - Google Patents

Description

Aug. 2, 1938. J. w. JOHNSTON GRADING MACHINE Filed April 24, 1935 5 Sheets-Sheetd Aug. 2, .1938. w, JOHNSTON 2,125,295

GRADING MACHINE Filed April 24, 1955 ,3 Sheets-Sheet 2 LUZ":

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Aug. 2, 1938. J w JOHNSTON 2,125,295

GRADING MACHINE Filed April 24, 1935 3 Sheets-Sheet 3 l O i I I Fl g. 5 i

,' Mo -m Patented Aug. 2, 1938 UNITED STATES GRADING MACHINE James W. Johnston, Manchester, N. H., assignor to North American Holding Corporation, Syracuse, N. Y., a corporation of New York Application April 24, 1935, Serial No. 17,949

10 Claims.

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 thinnest spot as determined by a detector.

The invention consists in certain improvements in the setting mechanism, through which the measuring movements of the detecting mechanism are transmitted to the grading mechanism, whereby the adjustment of the. grading mechanism in response to the detecting'mechanism is rendered more accurate and certain causes of inaccuracy in prior machines are corrected.

The invention is applicable to grading machines generally, and the expression grading mechanism, as herein used (unless limited expressly or by the context to some particular kind of grading mechanism), is used in the generic sense established in this art, and includes visual indicators, marking devices, sorting devices and evening devices.

For the purpose of illustration, however, a machine in which the brading mechanism consists of a visual indicator will be used to explain the invention, since it is to such a machine that the invention is especially applicable. As a specific example of such a machine, reference is made to the Cogswell Patent No. 1,820,010, dated August 25, 1931, for a more full and detailed description of its construction and mode of operation. Since the general characteristics of such machines are well known it will be necessary to describe herein only such parts as will aid in an understanding of the present invention.

In the accompanying drawings which illustrate the invention,

Fig. 1 is a side elevation of a grading machine embodying the invention, parts of the machine being broken away and parts being omitted for 40 the sake of clearness;

Fig. 2 is a detail in elevation, on a larger scale showing the detecting rolls and certain parts of the setting mechanism associated therewith;

Fig. 3 is a partial plan view and section on line 45 3-3 of Fig. 1 on a larger scale; a

Fig. 4 is a detail in plan of a modification hereinafter described; and

Fig. 5 is an elevation partly in section on line 5-5 of Fig. 4.

The machine herein illustrated comprises a pair of continuously driven-detecting and feeding rolls l0 and II to which the soles or other blanks I2 to be graded are automatically fed one at a time from the bottom of a magazine or hopper I3. The shelf I4 attached to the frame of the machine constitutes the bottom or floor of the magazine I3 for supporting a stack of blanks I2. Feeding mechanism of known construction, parts of which are shown at I5, I6, I1 and I8, slides the lowermost blank in the stack forwardly along 5 the shelf I4 to the rolls I 0 and I I, which constitute the detecting mechanism for detecting or measuring the grade of successive blanks according to their thickness, and which also feed or propel the blanks forwardly through the machine. 10 For a more detailed description of the mechanism for feeding the blanks from the magazine to the detecting rolls, reference may be had to said Patent No. 1,820,010.

The upper roll I0 is journaled in fixed bearings 15 on the frame of the machine. The lower roll II is yieldingly supported and is normally pressed upwardly toward the upper roll I0 by the usual mechanism including a coil spring I9 and a pair of bell-crank levers I9 hence the lower roll automatically fits itself to the bottom side of the blank by bodily movements toward and from the upper roll and also by tilting movements in case the blank is uneven from side to side.

The lower roll I I is journaled in bearings near the free ends of a pair of pivotally supported arms 20. The free ends of the arms 20 are connected by a yoke 22, whose ends 2I are pivoted in the ends of the arms 20. Pivotally connected to the yoke 22 are a pair of rods 23 each having a pin 24 at its lower end. Each pin 24 is engaged by a notch at the end of a lever arm 25 fixed to the rock shaft 26. The notches engage the tops of the pins 24 and are open at their under side. Therefore, either rod 23 may move downwardly independently of the other in response to tilting movements of the lower detecting roll II, and any upward movement of either end of the roll II in response to a thin spot in the blank being measured will be transmitted to the rock shaft 26 notwithstanding the other edge of the blank may be relatively thick and consequently may not move the other rod 23 to the same extent.

At one end of the rock shaft 26 there is fixed an arm 3I provided at its free end with a gear segment 32 meshing with an endwise movable rack 33. The rack 33 is loosely mounted to slide upon the lower end of a rod 34 and is held in mesh with segment 32 and guided in its vertical movements by means of a flanged roller 35 journaled on a suitable bracket fixed to the frame of the machine. The lower end of rack 33 abuts against an adjustable nut 36 threaded on the lower end of the rod 34, and the upper end of rack 33 abuts against one end of a coil spring 31 surrounding the rod 34. The upper end of the coil spring 3'! abuts against a collar 38 fixed;

to the rod. Thus downward movement of the arm 3| and segment 32 will positively move the rod 34 downwardly, while upward movement of the arm 3| and segment 32 will move the rod 34 upwardly, acting through the rack 33, coil spring 31 and collar 38, providing the rod is free to move upwardly. When the rod 34 is locked against upward movement any upward movement of arm 3| will merely act through the sliding rack 33 to compress spring 31.

Rigidly but adiustably fixed to the upper end of rod 34 is another rack 39 meshing with a pinion 46, fixed to the spindle or shaft 4i carrying a pointer 42, which constitutes part of a visual indicator of known form. The usual indicator scale, not shown, is applied to the fixed segment 43. The rack 33 is held in mesh with the pinion 40 by a guide block 44 rigidly fixed to the frame of the machine and having a sliding engagement with the back side of the rack 39.

The mechanism by which only the thinnest measurementof a blank; as determined by the detecting rolls, is transmitted to and preserved by the indicator is well known in this art and may be; substantially the same as that described in saidPatent No. 1,826,010.

The machine in its general construction and mode v of operation may be the same as known machines of the prior 'art and no further de, tailed description will'be necessary to an under= standing of the present invention;

The present invention resides in certain improvements inythesetting mechanism through which the measurements ascertained by the detecting mechanism (herein shown as detecting rolls l0 and I!) are transmitted to the grading mechanism (herein shown as a visual indicator including the pointer 42), and its object is to increase the accuracy of the adjustment of the grading mechanism in response to the delicate measurements ascertained by the detecting mechanism, and to counteract causes of inaccuracy which were inherent in the former machines.

It'is obvious that in order to secure an accurate adjustment of the grading mechanism in response to the. detecting mechanism, the setting mechanism must be so constructed as to insure a definite, predetermined ratio between the extentcof movement of the detecting mechanism and the extent of the adjustment of the gradingv mechanism. If the machine is designed and constructedfor a given; ratio any'departure from thatratio will result inincorrect grading. In grading machines for performing certain types of grading, such, as visually indicating, marking or sorting the blanks according to their grade, it is necessary that the movements of the detect ing mechanism be greatly amplified the movements transmitted to the grading mechanism. For example, in the machine herein shown for the purpose of illustration, it will be observed that the extent of the movement imparted to the lower detecting roll II by ablank passing between'the'rolls l0 and H is small, the maxi-' mum 'range'of such movement being in the case of a leather sole, for instance, only a small fraction of an inch. small detecting and measuririg' movement of the roll l l in being trans mitted through the setting mechanism to the grading mechanism (the visual indicator) is, greatly multiplied in the movement of the pointer 42; Ccnseqt'iently if there is any inaccuracy in the setting mechanism, which transmits the measurements found by the roll H, such inaccuracy will also be multiplied and aggravated in the reading of the indicator.

In the commercial manufacture of these ma= chines it has been found, as a practical matter, well-nigh impossible or difiicult to construct all of them .exactiy alike so as to insure a correct ratio between the movement of the detecting roll and the movement of the grading device. Since the effective length of the lever arms 25 is an important factor controlling the extent of adjustment of the grading device, it has been the practice to specially construct each such lever arm as required to make it the correct length for the individualrnachine in which it was used.

Heretofore the lever arms'25 have been fastened directly upon the rock shaft 26 and the effective length of each lever arm, as represented by the distance between the axis of the shaft 26 and the axis ofpin 24, could not be varied.

In accordance with the present invention the hub of each lever arm 25' instead of being mounted directlyon rock shaft 26 and therefore being always concentric therewith, is mounted on an eccentric which is 'rota'tively adjustable on the rock'shaft, whereby the effective length of the lever arm from the axis of the rock shaft 26 to the axis of pin 24 may be varied. The hub of each' lever arm. 25 is split and clamped rigidly in position upon a split eccentric 2l= by means of a bolt 28, the contraction of the hub of the arm 25 by the bolt28 serving also to. clamp the split eccentric"'2 'l tightly on'the rock shaft 26 so that normally the rock shaft, the spliteccentric 27 and the lever arm 25move together.

As shown in Figs. 2 and 3, there is a split eccentric 27 for each of. the two arms 25. The two. eccentrics are integrally or rigidly connected with an intermediate unsplit sleeve or hub 29, loosely surrounding shaft 26, and provided with an armor handle 30: by means of which the two eccentrics may berotatively adjusted. in unison on the rock shaft after the screws 28 are loosened;

By thus varying the efiective length of the arms. 25 the. ratio between the movements of the detecting mechanism and the movements of. theigrading mechanism can be accurately regulated. I

It sometimes.v happens. that it is. necessary to Vary the eifective length of only one of the lever armsf25, oi to vary one more than the other, 'or to lengthen one and shorten thelother. In order to accomplish these ends. and tomake it possible either to adjust the two eccentrics independently of. eachjother or to adjust them. together as a. single part, asmay be desired; Ihave' provided an alternative construction consisting of two sepa rate and independent split'eccent'ric's 21 and 21!, as. showninFigs. 4 "and '5. These individually adjustable split eccentrics will be clamped This sleeve abuts against the similar sleeve on eccen ric-"21 and carries an arm" '49 which extends alongside the arm. A headed screw 48 projects through slot "47 and is threaded into ment over the dial.

the arm 49. When the screw 48 is set up tight and the clamping bolts 28 on the split hubs of the lever arms 25 are loosened, the two eccentrics 2'! and 2'! may be rotated together as a single part in the same manner as described in connection with the structure shown in Fig. 3; but when the screw 48 is loosened, either eccentric 21 or 21* may be adjusted independently of the other, thereby varying the effective length of either lever arm 25 to whatever extent may-be necessary, independently of the other.

Another error inherent in the construction of the prior grading machines of the kind herein illustrated has been due to the fact that the lower end of the rod 34 has been pivotally connected to the free end of the arm 3|, with the result that as the arm 3| swings'up and down said pivotal connection moves in the arc of a circle, thereby laterally displacing the lower end of rod 34 to such an extent that it has been necessary to provide for pivotal movement of the guide block 44 on the screw 45, by which the guide block was loosely attached to the frame of the machine. This construction introduced an error into the operation of the grading device due to the lateral swinging movement imparted to the rod 34, which also caused the rack 39 to rock on the axis of screw 45. It will be understood that it was customary to set up the machine so that when the arm 3| was horizontal the pointer 42 would be in a vertical position midway between the two extremes of its move- The result was that when the pointer was swung toward either of its extreme positions in response to a very thick or a very thin blank it would not accurately record the true measurements of the blank. The construction herein described by which the up and down movements of the arm 3| are imparted to the rod 34 through a gear segment 32 and rack 33 makes it possible to confine the rod 34 and rack 39 toa true rectilinear movement, which correctly transmits to the pointer 42 the measuring movements of arm 3|.

I claim:

1. A grading machine comprising detecting mechanism for detecting the grade of successive blanks according to their thickness, adjustable grading mechanism controlled by the detecting mechanism, and setting mechanism for setting the grading mechanism in accordance with the grade of the blanks as determined by the detecting mechanism, said setting mechanism including means whereby the ratio between the movement of the detecting mechanism and the movement of the grading mechanism may be varied.

2. A grading machine comprising detecting mechanism for detecting the grade of successive blanks according to their thickness, adjustable grading mechanism controlled by the detecting mechanism, and setting mechanism for setting the grading mechanism in accordance with the grade of the blanks as determined by the detecting mechanism, said setting mechanism including a rock shaft, an eccentric rotatively adjustable on the rock shaft, and a lever arm having a hub embracing the eccentric, whereby the effective length of the lever arm may be varied by rotating the eccentric relatively tothe rock shaft and the lever arm.

3. A grading machine comprising detecting mechanism for detecting the grade of successive blanks according to their thickness, adjustable grading mechanism controlled by the detecting mechanism, and setting mechanism for setting the grading mechanism in accordance with the grade of the blanks as determined by the detecting mechanism, said setting mechanism including a rock shaft, an eccentric rotatively adjustable on the rock shaft, and a lever arm having a hub embracing the eccentric, whereby the effective length of the lever arm may be varied by rotating the eccentric relatively to the rock shaft and the lever arm and means to fasten the parts in adjusted position.

4. A grading machine comprising detecting mechanism for detecting the grade of successive blanks according to their thickness, adjustable grading mechanism controlled by the detecting mechanism, and setting mechanism for setting the grading mechanism in accordance with the grade of the blanks as determined by the detecting mechanism, said setting mechanism including a rock shaft, an eccentric in the form of split sleeve mounted on the rock shaft and rotatively adjustable thereon, a lever arm having a split hub embracing the eccentric, and means to fasten the parts in adjusted position.

5. A grading machine comprising detecting mechanism for detecting the grade of successive blanks according to their thickness, adjustable grading mechanism controlled by the detecting mechanism, and setting mechanism for setting the grading mechanism in accordance with the grade of the blanks as determined by the detecting mechanism, said setting mechanism including a rock shaft, an eccentric in the form of split sleeve mounted on the rock shaft and rotatively adjustable thereon, a lever arm having a split hub embracing the eccentric, and a single clamping device serving both to clamp the split hub on the eccentric and to clamp the split eccentric on the rock shaft.

6. A grading machine comprising detecting mechanism for detecting the grade of successive blanks according to their thickness, adjustable grading mechanism controlled by the detecting mechanism, and setting mechanism for setting the grading mechanism in accordance with the grade of the blanks as determined by the detecting mechanism, said setting mechanism including a rock shaft, two eccentrics in the form of split sleeves connected together for rotative adjustment as a single part and mounted on the rock shaft, two lever arms each having a split hub embracing one of the eccentrics, and means to fasten the parts in adjusted position.

7. A grading machine comprising detecting mechanism for detecting the grade of successive blanks according to their thickness, adjustable grading mechanism controlled by the detecting mechanism, and setting mechanism for setting the grading mechanism in accordance with the grade of the blanks as determined by the detecting mechanism, said setting mechanism including a rock shaft, two eccentrics, each in the form of a split sleeve mounted on the rock shaft and rotatively adjustable thereon each independently of the other, two lever arms each having a split hub embracing one of the eccentrics, and means to fasten the parts in adjusted position.

8. A grading machine comprising detecting mechanism for detecting the grade of successive blanks according to their thickness, adjustable grading mechanism controlled by the detecting mechanism, and setting mechanism for setting the grading mechanism in accordance with the grade of the blanks as determined by the detecting mechanism, said setting mechanism including a rock shaft, two eccentrics, each in the form of a split sleeve mounted on the rock shaft and rotatively adjustable thereon each independently of the other, two lever arms each having a split hub embracing one of the eccentrics, and means to fasten each huband its eccentric to the shaft independently of theother hub and its eccentric. V

9. A grading machine comprising detecting mechanism for detecting the grade of successive blanks according to their thickness, adjustable grading mechanism controlled by the detecting mechanism, and setting mechanism for setting the grading mechanism in accordance with the grade of the blanks as determined by the detecting mechanism, said setting mechanism including a rock shaft, two eccentrics, each in the form of a split sleeve mounted on the rock shaft and ,rotatively adjustable thereon each independently of the other, two lever arms each having a split hub embracing one of the eccentrics, and means to fasten each hub and its eccentric to the shaft independently of the other hub and its eccentric and means operable to adjust both eccentrics together and also operable to adjust eitherpeccentric independently of the other.

10. A grading machine comprising detecting mechanism for detecting the grade of successive blanks according to their thicknessyadjustable grading mechanism controlled by the detecting mechanism, and. setting mechanism for setting the grading mechanism in accordance with the grade of the blanks as determined by the detecting mechanism, said setting mechanism including a rock shaft, two'eccentrics, each in the form of a split sleeve mounted on the rock shaft and rotatively adjustable thereon, an unsplit sleeve loosely mounted on the rock shaft and rigidly connected to both eccentrics, an operating member on the unsplit sleeve for rotatively adjusting the two eccentrics, and two lever arms each having a hub embracing one of the eccentrics.

. JAMES W. JOHNSTON.

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