US2024108A - Method of and means for operating on sheet metal articles - Google Patents

Description

Dec M, 19356 c. F. MERRILL 1-:r AL 220249108 METHOD OF AND MEANS FOR OPERATING ON SHEET METAL ARTICLES Filed Sept; 6, 1933 2 Sheets-Sheet l a m w L m N Em. /\O Wi W Z EC J ET mu wc 1935- c. F. MERRILL ET AL 2,024,108

'METHOD OF AND MEANS FOR OPERATING ON SHEET METAL ARTICLES Filed Sept. 6, 1933 2 Sheets-Sheet 2 Z 32 INVENTORS. W/ 71 555. CHA/E'LES F. MERE/LL C2 /N7' /Y\5. CoBlJE/Y. 650565 (I You/vs ATTTDRNEY.

Patented Dec. 10, 1935 UNIT ED STATES.

IWETHOD OF AND MEANS FOR OPERATING ON SHEET METAL ARTICLES Charles F. Merrill and George C. Young, Hopedale, Mass, assignors to Draper Corporation, Hopedale, Mass, a corporation of Maine Application September 6, 1933, Serial No. 688,362

17. Claims.

The present invention pertains to the making of sheet metal articles such as drop wires and to the removal of burrs from apertures therein. We will disclose, as a specific example of the utility of our invention, adaptation of the sameto the making of drop wires only, but it should be understood that such=disclosure is intended to be illustrative rather than for purposes of limitation, the true scope of the invention being defined in the appended claims.

A drop wire of the type herein disclosed is a flat sheet metal article usually provided with a detector-bar slot and a thread aperture. These drop wires are utilized in warp stop motions of looms by being'suspended from the warp threads, which threads pass through the thread apertures mentioned. It is of utmost importance that the drop wires, and particularly the apertures therein, present no sharp or rough edges which would be likely to chafe or break the threads. Commercial methods of forming apertures in sheet metal articles usually leave burrs on the edges of the apertures, and it is with the removal of such burrs that our invention is primarily concemed.

An object of the invention is to provide a novel burr-removing machine, in the form of a flying burr-removing tool such as a milling cutter operating on a continuously fed strip of' partially formed sheet metal articles.

A further object of the invention is to provide a novel and improved method of making apertured sheet metal articles and removing the burrs from the apertures therein.

Other objects will, in part, be herein-after more specifically enumerated and will, in part, become obvious as the description proceeds.

In attainment of the foregoing and other objects we have devised a method which embraces the steps of punching out a strip of sheet metal to form a series of connected, partially formed drop wires, thereafter feeding the strip continuously while removing the burrs therefrom, and subsequently severing the strip at intervals into individual drop wires.

For more detailed disclosure of the preferred embodiment of our invention, reference may be had to the accompanying drawings, of which:

Fig. 1 is a side elevation, partially diagrammatic and with parts broken away, of the form of machine which we prefer;

Fig. 2 is a detail of the preferred form of burrremoving tool;

Fig. 3 is a sectional elevation taken approximately on line 3-3 of Fig. 1, except that one of the spindles has been sectioned;

Fig. 4 is a fragmentary plan view of the work ing in section; and

Fig. 5 is a detail, in section, taken approximately on line 5-5 of Fig. 1.

In making drop wires in accordance with the present invention, a continuous strip of sheet metal of the same width as a finished drop wire 5 is utilized. The strip is continuous only in the sense that it is of indefinite length. The strip is then punched out to form a series of partially-formed drop wires W connected by narrow connecting portions C. The particular drop 10 wires illustrated are provided with circular thread apertures T and elongated apertures for slots S for reception of a detector bar (not shown). This is but one of the various forms of drop wires which may be made. 15

The apertures T and S, which are spaced apart longitudinally of the strip, must have the burrs removed therefrom before the drop wires can be put into use. In removing these burrs the strip of partially formed drop wires is fed by go means of a pair of continuously rotated drums I and 2. The portion W of the strip, Fig. 1, may come directly from a punch press, not shown, or from any other suitable source of supply. This: strip passes over the drum l and. proceeds as at W 25 past a burr removing tool 3 to drum 2. The strip then passes about the drum 2 and then in the opposite direction (toward the left in Fig. 1) todrum I. During this latter passage of the strip it is twisted about its own longitudinal axis by 39 pins 3, 5-, to present its opposite face to the drum I. After passing about the drum I by the side of the first run of the strip, the strip is fed parallel to the portion W past another burrremoving tool 6, as at W and thence to a pair 35 of continuously rotating feed rolls 1, I.

The tools 3 and B are, in the present embodiment, milling cutters of a special shape, although other burr-removing tools may be employed. These cutters are constructed and 40 mounted to operate on the strip while the latter is being continuously fed. The machine will be hereinafter more fully described.

The final step in the method, insofar as the same is of our invention, is cutting out the con- 5 necting portions C-in other words, severing the strip at regular intervalsto form individual drop Wires. The severing may be done by any suitable means, there being diagrammatically illustrated on Fig. 1 a conventional die 8 and double edged 5 shear blade 9 operated from a crank It by means of a pitman II.

It is noted that the shear operates on they strip while the same is being continuously fed, and such is the preferred mode of operation. How- 55 ever, the strip or the drop wires may be subjected to other operations either before or after any of the steps of the method herein disclosed.

In the preferred embodiment of machine for performing the burr-removingsteps of the meth- 0 0d, the mechanism is carried by a table l2 which.

may be mounted on legs l3, l3. Stands l4, [4 on the table support the feed drums l and 2 which are rotated continuously by any suitable means, not shown. Upright posts I5, 15 on the table support a fiat bed IS on which are mounted a work supporting block I! and standards [8, I8. The standards l8 are integrally joined by a hori- .zontal cross bar !9 which receives a shaft 20 which is fixed therein as by set screws 2|, 2| (Fig. 3).

It will be noted that'four spindles are supported on the shaft 28. The spindles carrying tools 3 and 6 operate, respectively on the portions W and W of the same strip. The spindles carrying tools 3' and 6 are duplicates of the other two but operate on a different strip. The duplication of parts to operate on, a plurality of strips simultaneously may be extended, to provide for still more strips, or the machine may be constructed to operate on only one strip.

Eccentric members 22 are loosely mounted on the shaft 20, one for each spindle. Like reference numerals are applied to all the spindles as.

they are of duplicate construction, and the description immediately following may be applied to any one of thespindles.

A frame 23 is bored to loosely receive the eccentric 22 but eccentric and frame are constrained to pivot together about the shaft 23 by means of a spring 24 engaging the notched periphery of a wheel 25 formed integrally with the eccentric. The construction is such that the eccentric may be manually rotated relative to the frame to thereby adjust the latter vertically. The frame 23 is provided with vertically spaced bearings 26, 21 in which the spindle 28 is slidably and rotatably mounted. A cap 29, fixed to bearing 26, is recessed to receive a coil spring 38 which bears at its lower end against a thrust bearing 3| for the spindle and its upper end against an adjusting screw 32 in the cap. By this means the spindle is yieldably urged axially toward the strip but is capable of a limited axial movement.

The vertical, or axial, movement of the spindle is limited by engagement of the driving pulley 33 with the bearing 26 or 2'1, the pulley being fixed to the spindle Pivotal movement of the frame 23 and spindle about the shaft 20 is limited by means of cross bars 34 extending entirely across the machine and carried by adjusting screws 35, 35 in the standards l8. The frame 23, beyond bearing 21 extends downwardly as at 36 and carries a horizontal cross member 31 which is engaged by the bars 34 to limit the aforesaid pivotal movement. A spring 38 may be interposed between the rear bar 34 and the cross member 35 to assist gravity in yieldingly urging the frame clockwise, Fig. 1, to thereby urge the tool laterally in a direction opposite to the direction of movement of the strip therebeneath.

A conventional collar or socket 39 is provided on the spindle for receiving the tool. The tool may also be guided by a bushing 40 carried by the cross member 3?. The spindle and tool may be rotated by any suitable means such as a system of belts and pulleys indicated generally at 4] and associated with the pulley 33.

It will be apparent that, by means of the fore going mechanism, the tool will be given a so-called flying movement. That is, the tool will have repeated cycles of bodily movements comprised of a movement axially into an aperture in the work, then laterally with the work while operating thereon, then axially out of the aperture and,

finally, laterally in a direction opposite to the direction of movement of the work, to the point of beginning, where it rests until the next succeeding aperture is presented to the tool. While various forms of tools may be used for the burr- 5 removing operation, there is shown in detail in Fig. 2 a milling cutter which it is preferred to use.

The milling cutter 3, Fig. 2, is of the so-called end mill type but modified from usual practice in 10 that the tip 42 is smooth, slightly rounded, and devoid of any cutting edges. The end of the cutter, as defined by the cutting portions 43, is frusto-conical and merges with very short, axially extending cutting edges 44. The diame- 15 ter of the cutter, at edges 44, is slightly less than the diameter of the thread apertures T and the vertical extent of these edges should be about equal to or less than the thickness of the sheet metal strip. Obviously, the shape of the cutting 20 edges 43, 44 may be varied to provide any type or shape of finished surface surrounding the apertures which may be desired. Furthermore, the invention in its broader aspects embraces the use of other burr-removing tools, such as tools 25 having an abrasive rather than a cutting action. However, any such tool which is spring-pressed toward the work and rides along the Work between apertures should be provided with a smooth tip, such as 42', to avoid mutilating the surfaces beso tween the apertures.

The rotating tool 3 is held substantially normal to the plane of the strip therebeneath and departs from a truly normal position only by reason of the fact that the present frame 23 has a pivotal rather than a sliding movement. It is contemplated that this as well as other of the particular means herein disclosed may be modified or changed within the scope of the appended claims without departing from the spirit of the 40 invention.

We claim as our invention:

1. In a method of removing burrs from punched apertures in sheet metal articles, the steps of continuously feeding a strip of sheet metal which contains spaced apertures for a plurality of such articles, removing the burrs from said apertures by rotating a tool and moving the same with the strip while operating in said apertures, and thereafter severing said strip at regu- 50 lar intervals into a plurality of said articles.

2. In a method of removing burrs from punched apertures in sheet metal articles, the steps of continuously feeding a strip of sheet metal which contains spaced apertures for a plu- 55 rality of such articles, removing the burrs from ,one face of said strip by rotating a tool in and strip lengthwise and, while the strip is being so fed, imparting to a rotating burr removing tool a cycle of movements for each aperture, which no cycle includes movements of the tool first, into operative engagement with a given aperture, then with the moving aperture while removing the burrs therefrom, then out of engagement with said aperture and, finally, opposite to the direc- 7 tion of movement of said strip to the point of beginning.

4. In a method of making and removing burrs from drop wires, the steps of continuously feeding a strip of sheet metal which contains longitudinally spaced apertures for a multiplicity of drop wires, removing the burrs from said apertures by rotating a tool therein while the strip is being fed continuously as aforesaid, and thereafter severing said strip at regular intervals to form a multiplicity of drop wires.

5. In a method of making drop wires, the steps of first punching longitudinally spaced apertures in a continuous strip of sheet metal without completely severing said strip, then continuously feeding the punched strip while removing the burrs from the apertures therein with a rotating tool, and thereafter severing said strip at regular intervals to form a multiplicity of drop wires.

6. In a method of making and removing burrs from drop wires, the steps of continuously feeding a strip of sheet metal which contains spaced apertures for a multiplicity of drop wires, removing the burrs from said apertures by simultaneously rotating a tool and moving the same with the continuously moving strip while operating on said apertures, and thereafter severing said strip at regular intervals to form a multiplicity of drop wires therefrom.

'7. In a method of making drop wires, the steps of taking a strip of sheet metal of the same width as a finished drop wire, simultaneously punching apertures and notches in said strip at intervals corresponding to the length of the finished drop wires, and thereafter continuously feeding the apertured and notched strip while performing thereon the operations of removing the burrs from the apertures therein and severing the strip at each notch, to thereby form a multiplicity of drop wires.

8. In a method of making and removing burrs from drop wires, the steps of continuously feeding a strip of sheet metal which contains spaced apertures for a multiplicity of drop wires, removing the burrs from said apertures by simultaneously rotating a tool and moving the same alternately with the continuously moving strip while operating on an aperture and in the opposite direction to engage the next aperture, and thereafter severing said strip at regular intervals to form a multiplicity of drop wires.

9. In a method of making and removing burrs from drop wires, the steps of continuously feeding a strip of sheet metal which contains spaced apertures for a multiplicity of drop wires, removing the burrs from said apertures with a rotating end mill by moving such mill alternately with the continuously moving strip in engagement with an aperture and in the opposite direction to engage the next succeeding aperture, and thereafter severing said strip at regular intervals to form a multiplicity of drop wires.

10. A machine for removing burrs from apertures in a strip of sheet metal, comprising in combination, means for continuously feeding said strip, a flying end mill entering into and operating on said apertures while the strip is being so fed, and means for operating said end mill as aforesaid.

11. A machine for removing burrs from apertures in a strip of sheet metal, comprising in combination, means for continuously feeding said strip lengthwise, a flying burr removing tool entering into and operating on said apertures while the strip is being so fed, and means for operating said tool as aforesaid.

12. A machine for removing burrs from longitudinally spaced apertures in a strip of sheet metal, comprising in combination, means for continuously feeding said strip lengthwise, a flying end mill entering into and removing the burrs from said apertures successively while the strip is being so fed, and meansfor operating said end mill as aforesaid.

13. A machine for removing burrs from apertures in a strip of sheet metal, comprising in combination, means for continuously feeding said strip, a rotating burr removing tool positioned approximately normal to the continuously fed strip, supporting and guiding means for said tool permitting the latter to move both normal to and longitudinally of the said strip, means for yieldingly urging said tool toward the strip and means for yieldingly urging said tool in a direction opposite to the direction of movement of the strip.

14. A machine for removing burrs from apertures in a strip of sheet metal, comprising in combination, means for continuously feeding said strip, an end milling cutter having a rounded non-cutting tip which cutter is positioned approximately normal to the continuously fed strip, supporting and guiding means for said cutter permitting the latter to move both normal to and longitudinally of the said strip, means for yieldingly urging said cutter toward the strip and means for yieldingly urging said cutter in a direction opposite to the direction of movement of the strip.

15. A machine for removing burrs from apertures in a strip of sheet metal, comprising in combination, means for continuously feeding said strip, a rotating burr removing tool having a smooth non-cutting tip which tool is positioned approximately normal to the continuously fed strip, supporting and guiding means for said tool permitting the latter to move both normal to and longitudinally of the said strip, means for yieldingly urging said tool toward the strip and means for yieldingly urging said tool in a direction opposite to the direction of movement of the strip.

16. A machine for removing burrs from longitudinally spaced apertures in a strip of sheet metal, comprising in combination, means for continuously feeding said strip lengthwise, a rotating burr removing tool having a smooth, noncutting tip, a movable carriage supporting said tool for movement longitudinally of said strip,

said tool being slidably supported by said carriage for movement normal to said strip, means for yieldingly urging said carriage and tool in a direction opposite to the direction of movement of said strip and means for yieldingly urging said tool toward said strip.

17. A machine for removing burrs from longitudinally spaced apertures in a strip of sheet metal of indefinite length, comprising in combination, spaced work supporting elements about which said strip is wrapped to provide two parallel runs of the strip, means for feeding said strip continuously, and a flying burr removing tool for each of said runs, said tools entering into and removing the burrs from opposite sides of said apertures while the strip is being fed continuously as aforesaid.

CHARLES F. MERRILL. GEORGE C. YOUNG.

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