US2176920A - Manufacture of grids and the like and machine therefor - Google Patents

Description

2 Sheets-Sheet l INVETOR, Cyprzan A. Nara/zd 7:0 MFM ATTORNEYS c. A. NARwlD Filed April 22, 1959 Oct. 24, 1939.

MANUFACTURE oF GRIDs AND THE LIKE AND MACHINE THEREFOR Oct. 24, 1939.

C. A. NARwlD MANUFACTURE 0F GRIDS AND THE LIKE AND MACHINE THEREFOR vFiled April 22', 1959 2 Sheets-Sheet 2 l I m0 MR 'lill'. VN @wm Il" m "l A A u. n 'lll 0 /w uw im. u' mi u' y n., C AlN/w IlIl' lul?!` l" Patented Oct. 24, 1939 UNITED STATES PATENT OFFICE MANUFACTURE OF GRIDS AND THE LIKE AND MACHINE THEREFOR Application April 22, 1939, Serial No. 269,399

20 Claims.

This invention relates to the manufacture of grids for radio tubes and the like, and particularly to a novel method and machine for the manufacture of such grids whereby the bows or bends often found in grids are prevented or controlled.

Grids for use in radio tubes and the like are usually manufactured by notching support wires carried by a relatively rotating mandrel, winding the grid wire into the notches and fastening the grid wire into the notches, as by swaging. The support wires after the notching, winding and swaging operations of conventional practice tend to bend or depart from a perfectly straightv position with the result that undesirable bows or bends are formed in the finished grids.

One object of the invention is to control the degree of the bow or bend of the support wires so as to avoid the undesirable bends or bows of the prior practice and to obtain grids approaching the straight or unbent character desired in practice.

Other objects of the invention will hereinafter appear.

For a better understanding of the invention reference may be had to the accompanying drawings forming a part of this application wherein:

Fig. 1 is an end view of a part of a grid machine embodying the invention;

Fig. 2 is a side elevational view thereof, partly in section;

Fig. 3 is a sectional View along the line 3-3 of Fig. 1;

Fig. 4 is a front view of a part of the mechanism;

Fig. 5 is a sectional view along the line 5 5 of Fig. 4;

Fig. 6 is an exploded view of a part of the mechanism;

Fig. 7 is a view indicating the undesirable bend or bow of a grid of conventional practice;

Fig, 8 illustrates the character of the grid which may be obtained according to the present invention;

Fig. 9 is a diagrammatic View indicating the principle of the invention; and

Fig. 10 is a diagrammatic View showing a modic cation.

Referring to the drawings there is shown a grid machine embodying the conventional notching Y wheel I rotatably mounted in a frame 2, a con- (Cl. L10-71) a reel I2 for supplying the grid wire I3. It is understood that the supply wires ID and II are furnished by a reel which is mounted for rotation with the spindle 5, and also that there is suitable means provided, omitted from the drawings for convenience in illustration, for engaging and drawing the support wires Il) and II over or through the mandrel 9. This means is located to the left of Fig. 2 and in line with the grid 'I being manufactured and engaging and pulling the support wires III and II together with the grid formed thereon towards the left as indicated by the arrow.

These mechanisms operate as in conventional practice to draw the support wires I0 and II through the machine, beneath the notching wheel I, and over the swaging wheel 3. The notching wheel I forms the notches indicated in the support wires I0 and II (Figs. 7 and 8) for the reception of the grid wire I3. After the positioning of the wire I3 in a notch, the swaging wheel 3 fastens the grid wire firmly to the support wire by the usual swaging operation. The swaging wheel 3 is movable toward and away from the mandrel 9 by a mechanism omitted for convenience in illustration for the purpose of discontinuing at desired intervals the swaging operation. These intervals of non-swaging include the parts Where the grid length is severed for use in radio tubes and the like. The mandrel 9 on the one hand and the notching Wheel I and swaging wheel 3 on the other are relatively rotatable. In the particular embodiment shown the mandrel 9 is carried by the rotating spindle 5 while the notching wheel I and the swaging Wheel 3 are relatively fixed, though the wheels I and 3 are journalled for rotation or oscillation about their respective axes and are adjustable toward and away from the mandrel. As the mandrel 9 is rotated, that part of the support wire which projects above the grooves 9 in the mandrel 9 are engaged by the notching wheel I to form the notches, and similarly the swaging wheel 3 engages the support wires at the notches to swage the grid wire I3 into xed position on the supports.

In the production of grids according to the conventional practice the support wires IIl and II tend to bend towards the notched sides with the resultant bow or bend formed in the grid, as indicated slightly exaggerated in Fig. 7, and they also tend to become twisted out of co-planar relation. This renders the grid difficult to mount and assemble and the degree of bow or bend or twist of the grid support wires in the conventlional practice cannot be predetermined with any certainty.

Referring to Fig. 2 of the drawings, there is provided a pair of holding rollers I4 which are disposed in advance of the notching wheel l, which rollers engage the support wires lll and Il and hold the same iirmly in the grooves 9 of the mandrel 9, as set forth and described in my application Serial No. 212,161, led June 6, i938. These rollers i5 are journalled in the ends of the lever arms lll which are pivotally mounted and supported on a collar i3 fastened to the mandrel 9 or to a member carrying the mandrel 9. These lever arms ll carry at their other ends adjusting screws 29 which bear upon the mandrel support for adjustment of the pressure exerted by the rollers l5 upon the support wires lil and Il disposed in the grooves 9. Clamping screws 2l are indicated for locking the adjusting screws 29 in their adjusted position. The depth of the grooves 9 in the mandrel or mandrel support are suicient in the neighborhood of the clamping screws 29 to avoid the latter engaging the support wires iti and il, but the wires are exposed to engagement by the rollers l5 and the notching and abrading wheels at the mandrel 9 proper. 'I'he mandrel assembly comprises a shaft 25 and an integral reduced extension 2l beyond the ring 26. The latter is adapted to receive a detachable mandrel member 9 which may be fastened thereto in any suitable manner. In the particular structure illustrated, the mandrel 9 is inserted over the extension 2l and is `nrmly ciamped thereto by a screw 29 being` screw-threadedly attached to a corresponding screw-threaded opening 28 formed in the extension 2l, a collar 29 being provided on the screw 23 to enable the screw to rmiy fasten the mandrel 9 to the extension 2l in ring 29 to be carried thereby in a non-rotatable manner. The provision of a detachable mandrel 9 enables mandrels of different diameters and dimensions to be readily substituted for the making of different sizes and types of grids.

There is also detachably mounted upon the shaft 25 and extension 2i a bridge or bearing member 3d having grooves 39 therein, through which grooves the grid wires i@ and Il pass after the grid wire i3 is fastened to the wires l? and ll by the notching and abrading wheels. This bridge or bearing member is clamped tightly against the mandrel 9 by the screw 28 and collar 29 but is maintained in spaced relation thereto by means of a sleeve extension 3l, this extension, in the particular embodiment shown, being integrally formed with the bridge or bearing member 3d. In the embodiment of Figs. l to 6 and 9 a pair of wheels or idler rollers 32 are caused to engage the wires lil and ll of the formed grids at points on the opposite sides of the bridge or bearing member 3o. These wheels 32 and 33 apply to the support wires lil and l l, as the latter are relatively rotated therepast, bending forces or stresses to the short sections of support wires l!) and ll disposed therebetween which neutralize and offset the bending tendency of the wires IE) and l l produced during the wrapping and fastening of the grid wire i3 thereabout. Thus these wheels 32 and 33 in cooperative relation with the bridge or bearing member 33 apply to the wires I 0 and l i progressively as the grids are advanced longitudinally a series of upsetting or neutralizing strains for preventing the bow Shown'in Fig. 'i' and any twist therein and obtaining a straight grid as indicated in'Fig. 3. The support wires IU Vthis applies to each side of the mandrel.

and l l in Fig. 8 are also `brought into co-planar relationship, so that there is no twist. In Fig. 9 the actual bending is exaggerated in amount, but by engaging the wire at the points on each side of the member 39 to apply radially directed bending or strain upsetting forces the wheel members 32 and 33 do tend to impart to the wire slight bends in an inward direction with the inside oI the bends concave, as indicated in Fig. 9. The illustration, however, is exaggerated and instead of imparting to the short section of wire between the wheels 32 and 33 an actual radially inward bend these wheels may merely apply bending forces without actually effecting a bend, or if the wires l!) and li are actually curving outwardly, as indicated in Fig. 7, or tending to curve outwardly these rollers 32 and 33 may merely apply sufcient forces on the opposite sides of the `member 3d to straighten that short section at the other with respect to the distance from the member 3Q, each of the rollers 32 and33 being independently adjustable. `For whatever adjustment may be madethe members 32 and 33, in cooperation with the member 30, impart to the wires l@ and l l, after the grid wire i3 is fastened thereto, a series of inwardly bending or straightening forces, applied progressively as the grid' advances with the wires i@ and l! following the holding and guiding grooves 9 and 39', and with the results partly indicated in Fig. 8. The grooves 9 and 33 are preferably of the same radius as the wires lil and li. In the embodiment of Figs. l to 6 and 9 the bridge or bearing member 39 is illustrated as of the same diameter as the mandrel 9, that is, groove 39 is in line with and on a level with the groove 9" formed in the mandrel 9 and There are two of each such grooves 9 and 30 shown because the grid being produced is one having two spaced wires i9 and li the grid i3 is fastened.

The wheels 32 and 33 for applying the bending or straining forces to the support wire on the opposite sides of the member 39 may be supported in any suitable manner. bodiment shown they are carried by a bracket unit comprising a U-shaped casting 419, having an arm 3i with fastening slots #'12 formed therein for the accommodation of fastcningbolts 43, the

latter passing through the slots 42 vand screw` threadedly attached to the frame of the machine. The bolt slot connection shown provides for a slight adjustment of the casting 40. Each of the rollers 32 and 33 is journalled upon the lower end of a shaft i5 which is carried by .a block L16.V

Each of the shafts 45 and theblocks 46 are identical and a description of one unit will apply to the other unit. Each block is laterally slit or slotted at i? and d8 and is provided with openings for the reception of supporting pins M and 48', the supporting pins M and 48 being ilxedly carried by the legs of the casting 9. YAn opening for the pin 3l formsv the bottom of the slot 41 and an opening "for the pin d8 is formed in line` with the slot 48, but the latter extends beyond toA to bothof which wires 'e In the particular emf.

Y an enlargement 49. A screw bolt U and a corvel() responding screw-threaded recess in the block is utilized for clamping the sides of the block, determined by the slot 41, about the pin 4T', a slot or slit 52 being provided at right angles to the slot 41 to impart to the jaws formed by the slot 41 a sufficient degree of flexibility to fasten the block firmly to the pin 41. A similar screw bolt 5G passing downwardly through the block 43 and received in a screw-threaded opening formed therein serves to tighten the lower part of the block firmly against the pin 48. The shaft 45 passes through an` opening in the block and screwethreadedly receives an adjusting nut 54, the latter being disposed in a recess formed in the block. A tightening and locking nut 55 is provided on the upper end of the shaft 45 for the purpose of locking the shaft 45 in any adjusted position. The block is also provided with a slot 56 for each of the shafts 45 in which a guide pin or screw 5l fastened to the shaft 45 is disposed for guiding the shaft 45 in a longitudinal direction and for preventing rotary movement thereof. The locking nut 55 for one of the shafts 45 is made shorter than the corresponding locking nut 55 of the other shaft for the purpose of effecting a larger clearance betweenv the knurled surfaces thereof. Thus in addition to the adjustment of the whole casting through the slots 42 and bolts 43 there are two additional adjustments for each of the shafts 45, namely, each shaft may be adjusted towards and away from the axis of the spindle and mandrel to apply a greater or smaller bending force at thepoint of engagement with the support wire as may be desired. This adjustment is effected by releasing the locking nut or 55 and then by rotating the adjusting nut 54 to obtain the desired adjustment whereupon the locking nut 55 or 55 may be screwed home to lock this particular adjustment. Each block 46 may also be adjusted together with its shaft 45 along the supporting pins 41 and 48'. This is effected by releasing the clamping bolts 59 and 5|, sliding a block along the pins 41 and 48 to the point desired and then reclamping the block to the supporting pins by screwing bolts 50 and 5l home.

In the embodiment of Fig. 10 there is only a single roller 33 on a shaft 45 carried by a single block 46. In this case the bending or straighten- `ing force applying roller 33 engages and applies ably of the same radius, these grooves being in the plane of the axis. The difference in diameter however is exaggerated in Fig. 10 for convenience in illustration. I have obtained particularly good results with the member 69 having a spread or diameter of from .002 to .010 inch greater than that of the mandrel. The wires l0 and Il are thereby spread outwardly by the member 60 a distance of from 001 to .005 inch for each wire as the wire passes off the mandrel 9 and passes over the member E0. 'I'he operation of this ernbodiment of the invention is substantially the same as that of the mechanism set forth in my above mentioned pending application for letters patent.

Thus by the adjustment of the wheels or rollers 32 and 33 grids controlled as to the straightness desired may be obtained at will and this applies to both modifications of the invention. With the two rollers 32 and 33 and the bearing member 30 of the same diameter as the mandrel 9 the adjustment is easier and more flexible, although as set forth above and as set forth in my pending application above referred to, satisfactory results are obtained by the use of a single roller 33 and the spreader member 60 of Fig. 10. In either case as the grid support wires l and I l are advanced with the grid wire I3 fastened thereabout a succession of inwardly directed bending or straightening forces or stresses tending to give a straightening effect are applied to the grid support wires at a point or points beyond the mandrel, and progressively, with the result that the bending strains or forces imparted to the wires by the notching and grid wire fastening means are neutralized or offset to any degree that may be desired. A straight grid may be thus obtained.

I claim:

1. In a grid machine of the character set forth comprising a relatively rotatable mandrel and grid wire fastening means and means for feeding support wire along the mandrel and for feeding gnd wire thereto, the provision at a point beyond the mandrel of a bearing member over which the support wire with the grid wire fastened thereto passes and means for progressively applying pressure inwardly on the support wire at points beyond the mandrel and on opposite sides of the bearing member as the support wire advances.

2. In a grid machine of the character set forth comprising a relatively rotatable mandrel and grid wire fastening means and means for feeding v support wire along the mandrel and for feeding grid wire thereto, the provision at a point beyond the mandrel of a bearing member over which the support wire with the grid wire fastened thereto passes and means for progressively applying pressure inwardly on the wire at a point beyond the mandrel and on one side of said bearing member as the support wire advances.

3. In a grid machine of the character set forth comprising a relatively rotatable mandrel and grid wire fastening means and means for feeding support wire along the mandrel and for feeding grid wire thereto, the provision at a point beyond the mandrel of a bearing member over which the support wire with the grid wire fastened thereto,vr passes, and means for progressively applying pressure inwardly on the support wire at a point beyond the mandrel and the bearing member but closely adjacent to the latter.

4. In a grid machine of the character set forth comprising a relatively rotatable mandrel and grid wire fastening means and means for feeding support Wire along the mandrel and for feeding grid wire thereto, the provision at a point beyond the mandrel of a bearing member over which the;A

support wire with the grid wire fastened thereto passes and idler rollers for progressively applying pressure inwardly on the support wire at points beyond the mandrel and on opposite sides of the bearing member as the support wire advances.

5. In a grid machine of the character set forth comprising a. relatively rotatable mandrel and grid wire fastening means and means for feeding support wire along the mandrel and for feedingy grid wire thereto, the provision at a point beyond the mandrel of a bearing member over which the support wire with the grid wire fastened thereto passes and an idler roller for progressively applying pressure inwardly on the wire at a point beyond the mandrel and on one side of said :bearing member as the support advances.

6. In a grid machine of the character set forth comprising a relatively rotatable mandrel and grid wire fastening means and means for feeding support wire along the mandrel and for feeding grid wire thereto, the provision at a point beyond the mandrel of a bearing member over which the support wire with the grid wire fastened thereto passes and means for progressively applying pressure inwardly on the support wire at points beyond the mandrel and on opposite sides of the bearing member as the support wire advances, said bearing member being of vthe same radial dimensions as those of the mandrel.

7. In a grid machine of the character set forth comprising a relatively rotatable mandrel and grid wire fastening means and means for .feeding support wire along the mandrel and for feeding grid wire thereto, the provision at a point beyond the mandrel of a bearing memberoveravl-/ch the sup-port wire with the grid wire fastened thereto passes and means for progressively applying pressure inwardly on the wire at a point beyond the mandrel and on one side of saidbearing member as the support advances, said bearing member being of the same radial dimensions as those of the mandrel.

8. In a grid machine of the character set forth comprising a relatively rotatable mandrel and grid wire fastening means Aand means for feeding support wire along 'the mandrel and for feeding grid wire thereto, the `provision at a point beyond the mandrel of a bearing member over which the support wire with the grid wire fastened thereto passes and an idler roller for progressively applying pressure inwardly on the wire at a point beyond the mandrel and on one sideof said bearing member as the supportadvances, said idler roller beingy universally adjustable.

9. In a grid machine of the character set forth comprising a relatively rotatable mandrel and grid wire fastening means and means for feeding support wire along the mandrel and for feeding grid wire thereto, the provision at a point beyond the mandrel of a bearing vmember over which the support wire with the grid wire fastened thereto passes and an idler roller for progressively applying pressure inwardly on the wire at a point beyond the mandrel and on one side of said bearing member as the .support wire advances, said idler roller being adjustably mounted to Vary the spacing between the vroller and the bearing member and to vary the pressure to be Vapplied to the support wire.

10. In a grid machine of the character set forth comprising a relatively rotatable mandrel and grid wire fastening means and ymeans for feeding support wire along the mandrel and for feeding grid wire thereto, the provision at a point beyond the mandrel of ya bearing member over which the support Wire with the grid wire fastened thereto passes and an idler roller for progressively applying pressure inwardly on the wire at a point beyond the mandrel and on one side of said bearing member as the support wire advances, said idler roller being carried by a shaft which is longitudinally adjustable to adjust'the pressure to be applied tothe support wire and said shaft being mounted on a block which is mounted for adjustment at right angles to the other adjustment.

11. In a grid machine of the character set rforth comprising a relatively rotatable mandrel and `grid wire fastening means and means for feeding support wire along the mandrel and for feeding grid Wire thereto, the provision at a point beyond the mandrel of a bearing member over which the support wirewith the grid wire fastened thereto passes and idler rollers for progressively applying pressure inwardly on the support wire at points beyond the mandrel and on opposite sides of the bearing member'as the support wire advances, each of said idler rollers being adjustable independently of the other to vary the spacing thereof from said bearing member and to vary the pressure to be applied to the support wire.

12. In a grid machine of the character set forth comprising a relatively rotatable mandrel and grid wire fastening means and means for feeding support wire along the mandrel and for feeding grid wire thereto, the provision at a point` beyond the mandrel of a bearing member over which the support wire passes after the grid wire has been fastened to the support wire and means for progressively applying pressure inwardly on the support wire at points beyond the mandrel and on opposite sides of the bearing member comprising a pair of independently adjustably mounted carrying frames, an adjustable shaft carried in each of said frames, and idler rollers carried by the ends of said shafts for engaging said support wire at each revolution.

13. In a grid machine of the character set forth comprising a relatively rotatable mandrel and grid wire fastening means and means for feeding support wire along the mandrel and for feeding grid wirethereto, the provision at a point beyond the mandrel of a bearing member over which the support wire with the grid wire fastened thereto passes and an idler rollerA for progressively applying pressure inwardly on the wire at a point beyond the mandrel and on one side of said bearing member as the support advances, said idler roller being journalled on a longitudinally adjustable shaft and said shaft being carried by a block which is adjustably mounted upon a bracket, said block having an opening therethrough for the reception of a support rod and being slotted in the plane of the opening together with a clamping bolt for clamping the opposite sides of the slot against the support.

14. In a grid machine of the character set forth comprising a relatively rotatable mandrelv and v grid wire fastening means and means for feeding support wire along the mandrel and for feeding grid wire thereto, the provision at a point beyond the mandrel of a bearing member over which the support wire with the grid wire fasf mandrel.

16. In the manufacture .of grids by notching support wire and fastening grid wire thereto by abrading operations, the method which consists in progressively Aapplying inwardly bending stresses at fixed intervals to the support wire after the grid wire is fastened thereto.

17. .In a grid machine of the character set forth in claim 2 wherein the mandrel and the bearing member are providedwith grooves ofrsubstantially the same radius as that of the support wire for holding and guiding the support wire past the grid Wire fastening means and the pressure applying means.

18. In a grid machine of the character set forth in claim 1 wherein the mandrel and the bearing member are provided With grooves of substantially the same radius as that of the support wire for holding and guiding the support wire past the grid wire fastening means and the pressure applying means.

19. In a grid machine of the character set forth, comprising relatively rotatable mandrel and notching means and means for feeding support wire along the mandrel and for feeding grid Wire to the notches formed by the notching means, the

provision of means for exerting pressure against the support Wire radially of the mandrel at points both in advance of and beyond the notching means.

20. In a grid machine of the character set forth, comprising relatively rotatable mandrel and notching means and means for feeding support Wire along the mandrel and for feeding grid wire to the notches formed by the notching means, the provision of means positioned in advance of the notching means for pressing the support wires inwardly against the mandrel and means beyond the notching means for exerting an oppositely directed pressure upon the support wires.

CYPRIAN A. NARWID.

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