US2575346A

US2575346A - Apparatus for taper grinding elongated articles

Info

Publication number: US2575346A
Application number: US176650A
Authority: US
Inventors: Fredrick C Julian
Original assignee: SOUTH BEND TOOL AND DIE CO Inc
Current assignee: SOUTH BEND TOOL AND DIE CO Inc
Priority date: 1950-07-29
Filing date: 1950-07-29
Publication date: 1951-11-20
Anticipated expiration: 1968-11-20

Description

Nov. 20, 1951 c, JULIAN 2,575,346

APPARATUS FOR TAPER GRINDING ELONGATED ARTICLES Filed July 29, 1950 2 SHEETSSHEEIT l FREDR/CK C. JUL/AN Mam 3nventot Nov. 20, 1951 F. c. JULIAN 2,575,346

APPARATUS FOR TAPER GRINDING ELONGATED ARTICLES Filed July 29, 1950 2 SHEETSSHEET 2 3mbentor FREDR/CK C. JUL/AN Patented Nov. 20, 1951 APPARATUS roa TABER GRINDING.

ELONGATED ARTICLES Fredrick 0. Julian, South Bend,.Ind'.,. assignorzto SouthxBend Tool and Die;G0., Inc.'-,.S0.uth- Bend} Ind., a.- corporation of Indiana Application-July 29, 1950; Serial No.'17.6,'650

Claims (Cl. 51-103) This invention relates to improvements in grinding machinery, particularly to a modified centerless grinder, and to a method for taper grinding elongated work pieces;

Attachments for centerless grinders are known whereby the rate at which the work piece is urged through the grindingthroat'is synchronized with the .rate of change of thewidth of the throat to taper grind elongated rigid articles. Although certain of such heretofore known modified centerless grinders, and the methods employing them, have been found reasonably satisfactory for taper grinding rigid articles, such as reasonably heavy steel and even wood rods, no modified centerless grinder nor any attachment therefor; has heretofore been described which is suitable for the automatic and accurate tapering of rods characterized by arelatively low-degree of rigidity or stiffness coupled with considerable toughness. When it is attempted touse the heretofore known modified centerless grinders, wherein the work piece is invariably urged, at least in part, through the grinding throat by pressure applied to its end, for tapering-long rods having these characteristics, the rod invariably buckles and accurate grinding to a desired taper is impossible. This is true of long metal rodsof small diameter and particularly of plastic rodsand plastic rods reenforced with glass=fibersror glass threads, such as those used in the making of fishing rods-,- golf club handles and the like.

In an attempt to overcome thesedifi'iculties, it has been the practice in the past when tapering relatively limber rods,'such-as those just mentioned, to adjust the control wheel of the centerless grinder to provide a feed component to draw the work piece through the grindingthroat and then to operate the throat adjusting mech anism of the grinder manually. It is apparent that such a procedure can lead only to erraticand inconstant results with no twoground articles being more than approximately identical. This procedure also results in a high proportion ofv rejects due to inadvertant and excessive removal of stock. If, in an attempttoavoid an.

excessive removalof stock,aninsufilcientamount of stock is' removed duringa given pass: of the rod blank throughthe grinder, it must be re-- run and this can often be done-only after-considerable. testing and measuring to determinejust' wherethe additional stock-must be removed. It is apparent-that an apparatus and a method whereby limber elongated blanks of metal vorresinous materials and other flexible but tough compositions can beground 'rapidly, economically and accurately to a desiredtaper and without the exercise of an undue amount ofskill'on' the part of the operator. would be of great value.-

It is, therefore,.an object of thepres'entirrvention to provide apparatus and a method for taper-grinding elongated articles characterized by theirflexibility and toughness. Y

An additional object is to provide apparatus and a method for grinding elongated plastic-and glass fiber reenforcedplastic rods automatically and accurately to a desired longitudinal taper;

Anadditional object is-to provide an attachment for a centerless grinder whereby the latter can be used for the substantiallyautomatic and accurate taper grindingof elongated article's characterized by: their'fi'exibility and toughness;

An additional object. is to provide apparatus. for taper. grinding elongated articles capable-citadjustment to accommodate workpiecesof differ= ent lengths.

According to thepresentdnventi'on, these 'and related objects are accomplished. readily-and. economically by equipping: a substantiallyiconventional centerless. grinder with a'cam mechanism for advancing the regulating 'wheelirthereof to controlthewidth of thegrinding throat and providing adrivingmeans. for the cam having an adjustable speed. control. whichis synchronized with the; rate: of travel of the work piece: through. the grinding throat, the travel of the work piece. being: causedsubstantially entirely; by a. feed component of the regulatingswheel To. reduce the operativeskill' necessary and teen-- ablethe. rate of cam. travel to beset to'synchronizeaccurately with the. rate of travel of. thezwork piece, a..work. follower is provided: which either contacts lightly. or follows closely at a substantially constant distance the end ofithe work piece and which. is; actuated. in; synchronism with the travel of the cam.. A follower adjusting means is. providedto adjust the. ra-tioof the -.total travel of the. cam to the total-travelof. the. follower to: accommodate work piecesof differentlengths; It; is to be noted thatv the. work piece. follower at'no: time assistsmaterially in forwarding the work piece through the-grinding. throat;

In operating the apparatus, the regulating wheel is first: adjusted to provide a feed com? ponent. suitable for the particular kind of'work piece being operated upon; The rate of travel of the piece throughthethroat remains-sub given feed component of 'theregulating wheel. 7

The follower adjusting nieansis then adjusted to provide for a total travel of the work follower equal to the length of the taper desired on the work piece for each complete travel of the cam. The follower thus serves as a visual indicator of the rate of travel of the cam and hence of the rate of change in the width of the grinding throat with respect to the rate of travel of the work piece through the throat. By adjusting the speed of travel of the cam and work follower so that the latter moves at the same speed as the work piece, it is assured that the travel of the cam coincides in time with the travel of the work piece though the grinding throat and that the contour as determined by the cam surface is thus spread along the desired section of the work piece in the same longitudinal proportions as it appears on the cam. When a different taper or contour is desired, a correspondingly differently formed cam is inserted in the machine.

With a properly formed cam installed in the machine and with the total travel of the work follower adjusted to accommodate the length of the work piece being operated upon, it is merely necessary to forward a few test pieces through the grinder and adjust the rate of travel of the cam, and therefore of the work follower, until the follower moves at substantially the same speed as the work piece. Subsequent pieces can then be forwarded through the grinder rapidly and in quick succession with the production of substantially identical tapered articles with only occasional adjustment of the speed of the cam and work follower being required.

The invention can be best understood by reference to the accompanying drawing wherein there is shown one modification of the apparatus of the invention, certain of the parts being shown on a somewhat exaggerated scale for the sake of clarity, and wherein:

Figure 1 is an oblique view of a centerless grinder equipped with an attachment embodying features of the invention,

I .Figure 2 is a partial sectional elevation taken along theline IIII of Figure 1,

- .Figure 3 is a plan view, partly in section and rotated .90 degrees counter clockwise, taken along the line HI.III of Figure 2, and

Figure ,4 is a schematic view of an hydraulic system for operating certain of the parts.

In the drawing, the bed II of a centerless grinder has mounted thereon a journal I2 for thespindle of a grinding wheel I3 which can be rotated at a high grinding rate of speed in a clockwise direction for grinding the work piece. The bed II also supports a sliding bed member I4 on which is mounted for movement therewith and for relative movement thereto a regulating wheel unit designated, generally, by the reference numeral I5. The regulating wheel unit I5 has mounted thereon, conventionally by means of a suitably swiveled bracket or its equivalent (not shown), a head IS in which is journaled the spindle I! of a regulating wheel I8 rotatable at a relatively slow work-controlling rate of speed in a.clockwise direction. By adjustment of the swiveled bracket the regulating wheel can be positioned to give it a desired feed component for the work piece. The operative faces of the grinding and regulating wheels are separated from one another to form a grinding throat therebetween. Beneath the grinding throat there is positioned a work rest blade I9 secured to the sliding bed member I4 by means of a conventional work fixture or in any other suitable manner. The upper preferably fiat although it may in some instances be inclined downwardly in the general direction of the operative surface of the regulating wheel I3.

The bed member II has secured thereto at its end opposite the grinding wheel I3 a pair of laterally extending supporting arms or

members

23 and 23 with their top surfaces conveniently substantially continuous with the top of the bed II. Each of the supporting

arms

23 and 24 is conveniently formed and supported by welding one end of a suitable channel member of suitable length perpendicularly to one side of a plate 25 and securing the plate With stud bolts 21 along the upper edge of one side of the bed. For purposes of differentiation, the laterally extending supporting

members

23 and 24 are, for reasons which will be apparent, herein sometimes referred to as a pivot race supporting member" and a cam drive supporting member, respectively, it being understood that the former is on the side of the bed I I from which the work piece enters the grinding throat and the latter is on the opposite side. A suitable brace 26 extending between the bed II and the pivot race supporting arm 23 can be provided to hold the latter securely in place without springing.

A fulcrum supporting member 28 is also provided near the outer end of the pivot race supporting member 23 and may conveniently be a longitudinal member, such as a channel, welded or otherwise secured against the lower surface of the pivot race supporting member 23 and extending perpendicularly therefrom in a direction away from the normal position of the work piece support hereinafter described.

Suitable piers

29, 32 and 33, or other suitable supporting members, are provided to insure a suitable degree of rigidity of the supporting

members

23, 24 and 28.

In the modification shown providing for an hydraulic drive for certain of the members, a suitable hydraulic drive cylinder 34, fitted with

conduits

35 and 33 for admitting and venting an hydraulic fluid, is secured near the outer end of the upper surface of the cam drive supporting member 215 in a position substantially longitudinally parallel therewith. The hydraulic drive cylinder 34 contains a piston (not shown) and a piston rod 31 adapted to travel longitudinally in fluid-tight relationship through a suitable port and stuffing box in the end plate 3I of the cylinder 34 nearest the bed I I, the

conduits

35 and 36 being arranged so that the piston and piston rod 37 can be urged in either direction. The hydraulic system for driving the piston will be described in detail hereinafter.

A pivot race member, indicated generally by the reference numeral 38, is secured near the outer end of the upper surface of the pivot race supporting member 23. In the modification shown, the pivot race member 38 consists of an elongated channel member 39 positioned with the channel in its upper surface longitudinally parallel with the pivot race supporting arm 23, and a pair of elongated pivot slide retaining plates 42 mounted on the top of the sides of the channel member 39, each extending laterally a short distance over the channel so as to retain slidably within the channel an inverted T-shaped pivot slide 43. A series of bolts 44 pass through registering holes in the pivot slide retaining plates 42 and the channel member 39 and threadably engage the pivot race supporting arm 23. The piv- 0t slide 43 is of suflicient vertical thickness so or operative surface 22 of the work rest blade is I}? that its upper surface is in a plane which clears the upper surfaces -of the pivot slideretaining plates 42 and the heads of the bolts 44. An up! wardly projecting circular pivot pin 45 is mounted on the upper surface of the pivot slide 43.

The pivot slide 43 is secured at its end nearest the; bed H by a suitable connector 45, suchas a yoke and pin, to one end of a spacer rod 4? which is in turn connected at its other end by another suitable connector 48 to one end of an elongated plate cam 49. The other end of the cam 49 is connectedby a suitabl connector, 5!) of Figure 3, to theexposed end of the piston rod 31!. The piston rod 37, the plate cam 4-9, the spacer, rod 4'! and the pivot slide 43 thus form a longitudinally rigid assembly capable of longitudinal travel in either direction in response to pressure of hydraulic fluid on the piston within the cylinder 34. An adjusting means, such as a threaded connection and lock nut 52-, is preferably provided for making minor adjustments in the effective length of the spacer rod ll. Suitable adjusting means can also be provided between the cam and the piston rod;

The cam 49 is formed, in the modification shown, with the cam surface 53 on its edge nearest, thev regulating wheel unit [5, its opposite edge 5| being a, planar cam guiding surface. Also, in the-modification shown, the cam plate is narrower at its and connected to the piston rod 31 than at its, other end, the regulating wheel l 8 traveling toward the grinding wheel 53 during the forward travel of the cam 55 toward the hydraulic cylinder 34.: It will be apparent as the description proceeds, however, that cams can be used in which the relationships of the end widths and of the edges are reversed or otherwise varied from those just described, sometimes with a reversal of the direction of travel of the cam causing a forward travel of the regulating wheel.

The cam member 49, during its longitudinal travel, actuates a cam responsive slide member 54 which is adapted to slide in a plane normal to the line of travel of the cam and which is connected rigidly to the regulating wheel unit I5, the regulating wheel [8 thus being advanced or retarded, and the width of the grinding throat altered accordingly, in response to the longitudinaltravel ofthe cam.

The'cam responsive slide member 54 and its accompanying members will now be described in detail, particular reference being made to Figures 1, 2 and 3. A generally rectangular slide mounting block 55 is mounted and secured, e. g. by bolts 55, on the bed I! so as to clear the slide member 14 at the rearward limit of its travel during normal operation of the grinder. A pair of elongated angular slide retaining members 5! are secured, as by bolts 58, to the top surface of the block 55 defining an inverted T-channel longitudinally parallel with the block for retaining therein a slide member 54 consisting of an elongated block-like member having an inverted T- shaped cross section. The upper surfaces of the ribs 59 extending laterally from the loweredges of the slide member 54 engage the lower surfaces of the overhanging portions of the slide retaining members 57.

The cam-responsive slide member 54 has an upstanding clamp 52 formed integral therewith, or secured thereto in convenient fashion, in which is clamped rigidly one end of a regulating wheel unit thrust rod 63. A thrust rod shoulder El is provided on the thrust rod 53 to bear against the forward side of the clamp 52 and a hub 80 is'secured-as by a set screw 4| to the outerend of the thrust rod, the shoulder Bl; and-hub 4i preventing slippage of the rod longitudinally in the clamp. Clamp screws 65 are provided for tightening the jaws of the clamp 52. The other end of the thrust rod 63 is secured to the regulating wheel unit [5, preferably by way of; an adjusting device, such as a threaded adjusting sleeve 64,, for adjusting the effective length of the rod, suitable hand spokes 49 being provided on the hub 60 for turning the thrust rod 63 to effect theadjustment. It is apparent that other thrust rod securing and adjust? ing means can be employed, if desired, for securing the thrust rod 63 to the cam responsive slide 54 and for adjusting its length.

The upper surface 66 of the slide, mounting block 55 in provided with a transverse camchannel- 51 in which the cam 49-travels, the depth of the channel being, such that the lower and upper surfacesof the cam maintain sliding contact with the bottom of the channel and with the bottom of the cam responsive slide member 54, respectively. A series of cam guiding rollers or idlers 68 are positioned and aligned in the cam channel 5 and mounted on pins ill set in the bottom of the cam channel in such fashion that the planar-cam guide surface 5! bears on the peripheries thereof, to prevent lateral sliding motion of the cam 49 in a rearward direction, i., e. in, adirection, away from the regulating wheel unit l5. The transverse cam channel is, of course, sufftciently wide to accom: mo a e the camem'ding rollers 68' andth widest portion of thecam,

Forward of the cam and adapted to bear against the cam surface 53 thereof there is located a cam follower consisting of a cam follower roller 59 mounted on a cam. follower shaftlZ secured as by a set screw ii in a vertical bore 13 in the forward portion of the cam responsive slide member 54-. The cam follower roller 69 is, located mainly forward of the transverse cam channel 61 in a cam follower channel it in the upper surface of the slide mounting block 55 intersecting the cam channel 5'! and shaped to permit lateral travel therein of the cam follower roller 59 in. a directionparallel with the longitudinal axis, of the thrust shaft 63.. Inasmuch as the camfollower roller 69 preferably has a face wider than the cam face 53, the cam follower channel it is, in such case, deeper than the cam channel G'I-and a shallow channel, 15 is formed in the lower surface of the cam responsive slide member 55 in register with the cam follower channel 34.

It is apparent that the cam 55 will, duringits travel in one direction, forward the regulating wheel toward the grinding wheel and decrease the width of the grindingthroat but that duringits travel in the reverse direction it will not. return the regulating wheel to its original position. To accomplish this latter effect and to maintain the cam follower roller 59 at all times in pressure con.- tact with the cam surface 55 and the width of the throat at all times controlled by the cam, the slide mounting block 55 is bored longitudinally below the cam follower channel it to accommodate a regulating wheel unit return shaft 15 which is secured at its forward end, as by threads and a lock nut 30, to the sliding bed member [5. The return shaft bore H accommodating the return shaft 16 terminates at its rearward end in a larger hydraulic return power cylinder 18, conveniently formed in a cylinder block 19 which is secured to the slide mounting block 55 as by bolts 82.

A piston 84, having suitable channel and ringaround its periphery to preventleakage of hydraulicfluidpast it is slidably positioned in the cylinder I8 and secured, as by a'piston securing nut 86, to the end of the return shaft 16. Hydraulic fluid is admitted under substantially constant pressure into the cylinder "I8 on the forward side of the piston 84 by way of a suitable fluid port 81 and a hydraulic fluid conduit 88 hereinafter more fully described. Due to the constant pressure of the fluid in the cylinder I8 on the forward side of the piston 84, the cam follower roller 69 will at all times be in pressure engagement with the cam surface 53 and the width of the grinding throat will at all times be controlled precisely by the contour of the cam surface 53. When the regulating wheel unit I is advanced in response to the urging of the cam surface 53 on the cam follower roller 69, hydraulic fluid is forced from the cylinder 18 through a suitable relief valve, as hereinafter explained, due to the forward movement of the piston 84. It is understood that after preliminary adjustment of the apparatus the sliding bed member I4 is locked to the regulating wheel unit I5, the two advancing and retreating as a unit. An additional advantage of the arrangement of parts shown is that because of the continuous pressure of the fluid in the return power cylinder I8 which opposes the pressure of the cam surface 53 on the cam follower roller 69, the adjusting means 64 for adjusting the length of the regulating wheel unit thrust rod 63 is always under compression. This compensates for any looseness or wear in the adjusting means and contributes to a high degree of accuracy in the synchronization of the travel of the regulating wheel unit I5 and the Work piece without the use of highly accurate and costly parts in the adjusting means and eliminates the necessity for their renewal upon the slightest amount of wear as would otherwise be the case.

An elongated work piece support 89 of Figure l, is provided, conveniently in the form of an clon gated trough, in which the work piece 92 is placed and along which it slides into the grinding throat to engage the grinding and regulating wheels I3 and I8, respectively. The work piece support 89 is secured at its end nearest the grinding throat, e. g. by welding, to a support plate 93 secured to the sliding bed member I4 as by bolts 90, or to a work holding fixture to which the blade I9 can also be secured, and is otherwise unsupported throughout its length. It thus advances and retreats with the slide member l4 and the regulating wheel I8 thus assisting somewhat in keeping the work piece 92 at all times aligned properly with respect to the grinding throat. It should be pointed out, however, that the alignment of the piece is effected principally by the grinding and regulating wheels themselves and that the machine will operate satisfactorily using a stationary fiat table as the work piece support if means are provided to guide the work follower pivot 96, hereinafter referred to, in the same longitudinal path as the work piece itself.

As indicated previously, a work follower is provided which follows the work piece 92 closely as it is drawn through the throat in response to a feed component of the regulating wheel. The work follower in the modification shown comprises a work follower rod 94 positioned in the work support trough 89 substantially coaxial with a work piece 92 therein. The rod 94 is secured at its outer end, i. e. at its end farthest removed from the grinding throat, to a work follower block 95 which is conveniently contoured to slide easily along the work support 89 without danger of becoming disengaged therefrom;

rotatably, on the top of the work follower block 95, the function of which will be hereinafter explained.

0n the fulcrum supporting member 28 previou'sly referred to there is positioned and secured a fulcrum bed block 91 longitudinally grooved in its upper surface to provide for the retention and sliding therein of a fulcrum block 98. The fulcrum block 98 has rotatably mounted on its surface a fulcrum member 99 bored to receive slidably one end of an elongated work follower actuating lever I02. The actuating lever I02 has a circular hole intermediate its ends for receivin the pivot pin 45 previously referred to and is prevented from becoming disengaged therefrom by a nut IOI threadably engaging the upper end of the pivot pin 45. The actuating lever I 02 is provided at its end removed from the fulcrum member 99 with an elongated follower pivot slot I03 to engage slidably the work follower pivot 96 to permit travel of the latter therein upon rotation of the actuating leverabout its fulcrum so as to cause the work follower rod and block 94 and 95, respectively, to travel along the work piece support 89 in synchronism with the lon itudinal travel of the cam 49. The parts are arranged so that the direction of travel of the pivot pin 45 is parallel with the direction of travel of the work follower pivot 96 for reasons hereinafter explained.

The fulcrum block 88, upon which the rotatable fulcrum member 99 is mounted, is longtudinally adjustable in the channel of the fulcrum bed block 9?, suitable by a threaded fulcrum block adjusting rod I04 secured to the end thereof and extending through a hole in a fulcrum block adjusting plate I05 secured at the end of the channel in the fulcrum bed plate 91. A pair of lock nuts I86, running on either side of the adjusting plate I05 on the adjusting rod I04, permits locking of the fulcrum block 98 at any position along the channel in the fulcrum bed block 91. It is apparent that, because the end portions of the work follower actuating lever I02 engage the fulcrum member 99 and the work follower pivot 96, respectively, in slidable manner and because the pivot pin 45 and the work follower pivot 96 travel in parallel paths, the distance traveled by the work follower rod 94 upon rotation of the work follower actuating lever I02 will at all times be in a constant ratio to the distance traveled by the pivot pin 45 for any par ticular setting of the fulcrum block adjusting rod I04.

It will be noted that, since the free end of the work piece follower rod 94 should, for best results, follow the work piece 92 at not more than a short distance so that the constancy of the distance can be judged accurately by the operator, and that since the grinding action on the work piece 92 continues until the piece has passed entirely through the throat, it would be essential that the diameter of the follower rod 94 be less than the diameter of the rear end of the workpiece as it leaves the grinding throat to prevent grinding of the follower rod unless some other means for preventing this were provided. Since this frequently presents some difficulty in the case of follower rods of small diameter in the way of keeping them straight and properly aligned it is sometimes advisable to provide means for arresting the travel of the work follower rod 94 before it has entered into the A grinding throat without at the same time ar- 9 zre'st-ing or changing :the rateof .travel either-of thework piece .92' throughthe throat end the This is accomplished :conveniently by-providing a lever elevating sarm' Ill'l adjacent to and sub- "stantia'llyiparallel withth'e end of the work piece support 89'nearest'th'e grinding throat which has awsloping upper surface or ramp I39 which engages .the traveling lever as it approaches the throatand springsitaupward sufliciently to disengage it from the work follower pivot 96, but

"without interrupting the forward travel of the lever. .Afterthe lever has completed its forward travel, which stops short'of 'itscontact with either the. grinding :wheel or the control Wheel, the direction of its travel is reversed, as hereinafter explained. As-it slides down the inclined surface 109 the follower pivot slot I03 again engages the work follower pivot 96. The lever elevating arm :I1I1'I is conveniently secured to a bracket I'IZ as by bolts H3 or by welding, the bracket II2 being in turn secured to the bed II as by bolts I I4.

The hydraulic system for operating the cam '43, shown schematically in Figure l, comprises 'anhydraulic fluid reservoir H5, a driving motor III and a'pump :IIifirfordr'awing fluid from the :reservoir and delivering it under high pressure throughasuitable high pressure conduit I-I8, the pressure therein being regulated to a convenient maximum value bya high pressure relief valve I I9, any excess of fluid furnished by'the pump re- "turning to the reservoir by way of a suitable pressure control drain conduit E22.

The high pressure conduit I18 conducts fluid to -"a.-suitable distributor valve I23. A neutral return conduit I21 conducts fluid from the distributor valve I26 back to the reservoir I I when the operating handle I28 is in neutral position. Fluid from anotheroutlet of the valve I23 is conducted, in-response to proper manipulation of the handle I28, by way of a regulator valve conduit I23 to a fluid regulator valve I32 adapted to careful and accurate control of the rate of flow of fluid therethrough. From the regulator valve I32 the fluid flows by way of conduit .35, previously mentioned, to the hydraulic drive cylinder 34 to cause forwarding of the cam in a forward direction, i. e. during the grinding of the work piece. The speed of the forward motion of the cam 49 and of the work follower rod 94 are regulated by means of the fluid regulator valve I32 to cause the follower rod to follow the Work piece at a substantially constant distance therefrom thus insuring synchronization of the travel of the work piece with the forward travel of the regulating wheel unit I5 and, accordingly, with the variation in width of the grinding throat.

Fluid from a third outlet of the distributor valve I26 is conducted, upon proper manipulation of the handle I28, by way of a cam return conduit I23 to a constant pressure inlet valve I24 and thence by way of a conduit 36, hereinbefore referred to, to the hydraulic drive cylinder 34 to cause retraction of the cam 49 and the work follower rod 94, it being apparent that the direction of travel of the cam and rod follower is determined by the position of the operating handle l 28 which is manipulated manually. During the travel of the piston in the hydraulic cylinder 34 in the forward direction during the grinding stroke in response to the pressure of fluid enter ing the cylinder through the conduit 35, the fluid in front of the piston is vented by way of a pressure relief valve I25 and a conduit I30 to the supply tank I I5. When the piston in the cylinder 34 is forced in the :oppositeidi-rection due to'pressure of :fluid entering through theconduit 36, 'fluid forced backwardthrough theregulator valve I32 and the conduit T129 and is by-passed through suitably provided .channels in the distributor valve 1.26 to the "conduit I'ZI-and :thence to :the

fluid reservoir I I5. "The fluid regulator valve I32 and the distributor valve I26 are usually mounted on the side of the bed member II, as

illustrated in Figure l, or in anyother location convenient for the operator.

A portion of the fluid passing into the high pressure conduit 'I IB flows by way of 'a constant pressure outlet valve 134 and thence byway .ofa conduit '88, previously referred 'to, to the return power cylinder I8 to maintain pressure at all times therein. An additional pressure relief valve I35 is provided to relieve pressure-in the conduit88 and vent fluid from the cylinder-I8 during the forward travel of the cam 49. Fluid vented through the relief valve I35 drains by way of a vent drain 136 into the reservoir H5. A

suitable-distributorvalve drain I33 and aisuitable regulator valve drain I31 are also usually provided toconvey any fluid leaking from the respective valves to the reservoir II5.

It is apparent that proper operation of the apparatus will depend upon a :propersetting of the several constant pressure and pressure relief valves. The relief valve II9 should be set-to open at a pressure higher thanzthatat which the constant pressure inlet valve I24 is set to open and the constant pressure outlet valve I34 should be set to maintain a substantially constant working pressure in theconduit 88 and the cylinder "I8 somewhat less than that at which the valve I24 The pressure relief valve I35 should be set to open at a convenient pressurehigher than that for which the constant pressure outlet valve I34 is set but lower than that for which 'the relief valve II9 is set. The pressure relief valve I25 should be set to open at a-pressure somewhat lower than that at which the valve I I9 o ens but higher than that for which the valve I24 is set.

By such a setting of the respective valves, the

possibility that the pressure -'of hydraulic fluid in the cylinder 18 will fall-to 'an'undesirably-low value, especially during *theretracti'on of the cam when fluid is entering the cylinder 34 by way of conduit 36, is avoided.

Although the apparatus of the invention is, as mentioned previously, of particular value in the tapering of relatively flexible and limber elongated articles, it is pointed out that it is equally adaptable to the grinding of large or rigid articles as well. It should also be pointed out that, depending upon the contour of the cam surface of the cam used, the apparatus can be employed to impart a variety of contours to the work piece including straight tapers, parabolic tapers, reversed parabolic tapers and combinations thereof including sections ground without a ta er. It is also a parent that, although the invention has been described as operating to grind a tapered article beginning at the larger end, the cam can be reversed and the work piece ground from the sm l er toward the larger end.

The manner of dres ng he grinding and regulatina Wheels and of adiusting the. latter to s cure a d sired feed component have not been described in detail as these operations and ad ustments ill be fu ly a arent o those familiar with the art. It should be articularly ment oned. however, that best results are obtained w en grinding relatively limber articles of small diameter by adl1 justing the height of the work rest blade so that the longitudinal axis of the work piece as it travels through the grinding throat is below a line connecting the centers of the grinding and regulating wheels. Thus, in the grinding of glass fiber reenforced fishing rod blanks, this distance is usually maintained at about one inch.

I claim:

1. In a machine for contouring longitudinally the surface of an elongated article having circumferentially opposed grinding and regulating wheels defining a grinding throat therebetween through which a work piece travels for grinding in response to a feed component of the regulating wheel, the latter being mounted slidably to vary the width of the throat, the combination including: an elongated cam slidable longitudinally in a cam race in a direction parallel with the direction of travel of a work piece through the throat, the sliding movement of the regulating wheel mounting and the variation in width of the throat being responsive to the longitudinal movement of the cam; a work piece support and a work piece follower slidable along the support; means synchronously responsive to the longitudinal movement of the cam to drive the work follower along the work support; and adjustable means to drive the cam longitudinally.

2. In a machine for contouring longitudinally the surface of an elongated article having circumferentially opposed grinding and regulating wheels defining a grinding throat therebetween through which a work piece travels for grinding in response to a feed component of the regulating wheel, the latter being mounted slidably to vary the width of the throat, the combination including: an elongated cam slidable longitudinally in a cam race in a direction parallel with the direction of travel of a Work piece through the throat, the sliding movement of the regulating wheel mounting and the variation in width of the throat being responsive to the longitudinal movement of the cam; a Work piece support and a work piece follower slidable along the support; a lever slidably engaging its fulcrum at one end and slidably engaging the work piece follower at its other end and rotatable about its fulcrum in response to longitudinal travel of the cam, the force for rotating the lever being applied at a pivot point intermediate its ends which travels during the rotation of the lever in a path parallel with the direction of travel of the cam; and adjustable means to drive the cam longitudinally.

3. Apparatus as claimed in claim 2 wherein the fulcrum is adjustable in a direction transverse to the direction of travel of the cam.

4. In a machine for contouring longitudinally the surface of an elongated article having circumierentially opposed grinding and regulating wheels defining a grinding throat therebetween through which a work piece travels for grinding in response to a feed component of the regulating wheel, the latter being mounted slidably to vary the width of the throat, the combination including: an elongated cam slidable longitudinally in a cam race in a direction parallel with the direction of travel of a work piece through the throat; a cam responsive member including a cam follower slidable in a direction transverse to the direction of travel of the cam and connected with the control wheel mounting to cause travel of the latter in response to the longitudinal movement of the cam; a work piece support and a work piece follower slidable along the support; means responsive to the longitudinal travel of the cam to drive the work follower along the work support at a speed having a predetermined constant ratio to the speed of the cam; and means to drive the cam longitudinally and to regulate the speed of its travel.

5. Apparatus as claimed in claim 4 including means to resist slidable movement of the cam responsive member and to maintain the cam follower at all times in pressure contact with the cam surface.

FREDRICK C. JULIAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,864,584 Cowdery June 28, 1932 1,891,663 Booth Dec. 20, 1932 2,304,580 Luers Dec. 8, 1942 2,463,783 Lind Mar. 8, 1949