US2557248A - Grinding machine - Google Patents

Description

B. P. APPEL ET AL June 19, 1951 GRINDING MACHINE 3 Sheets-Sheet 1 Filed Aug. 9, 1947 INVENTOR- U 5 4 M A. a f A NF 22 5 .B

June 19, 1951 Filed Aug. 9, 1947 B. P. APPEL ET AL GRINDING MACHINE 3 Sheets-Sheet 2 llHlm jbssp/l Ff flux/w W M g INVENTOR. 5m/vm: APPEL B. P. APPEL ET AL GRINDING MACHINE June 19," 1951 Filed Aug. 9, 1947 3 Sheets-Sheet 3 INVENTOR.

flew/men R Ap s; BY Jszpn ALu/m/v 7' TORNE Y5 Patented June l 1951 UNITED STATES. PATENT OFFICE;

GRINDING MACHINE Bernard ll. Appel, Cleveland Heights, and Joseph F. Klukan, Garfield Heights, Ohio, assignors to Chandler Products Corporation, Euclid, Ohio, a

corporation of Ohio Application August't), 1947, Serial No. 767,788

'Clain1s.

This invention relates to improvements in centerless grinding machines for grinding articles of circular cross section.

An object of the invention is to provide a novel and improved centerless grinder, having opposed rotatable grinding and regulatin wheels mounted in spaced relationship to forma work receiving throat, with improved means for sequentially feeding workpieces into the throat.

Another object of the invention is to provide a novel and improved centerless grinding machine having opposed grinding and regulating wheels, the machine being so constructed and arranged that the work is axially fed between the grindingv and regulatin wheels and is thereafter moved into engagement with the grinding Wheel and removed therefrom by operation of the regulating wheel without translation of the axis of the latter.

A further object of the invention is to provide a novel and improved centerless grindingmachine having opposed rotatable grinding and reg-, ulating wheels mounted in spaced relationship to form a work receiving throat therebetween, with. the said regulating wheel having a segment of its periphery removed to provide a recessed; portion and the remainder of the peripher in-' cluding an eccentric portion, the Work being axially inserted within the throat by an improved feeding means and thereafter moved. into-engagement with the grinding wheel by'the; saideccentric portion of the regulating wheel foreffectingmaterial removal, the recessed portion of:

the regulating wheel allowing the work to drop by gravity from itsposition within. the throatafter thegrinding is completed.

A still further object. of the invention is to provide a centerless grinder, having opposed ro=- tatable grinding andregulating wheels mounted in spacedrelationship, with improved means for;

feeding elongated workpieces axially into' the space between said wheels intimed relationship with the rotation of said *regulating wheel.

The invention further resides-in certain novel' features of construction, and combinations-and arrangements of parts, and further objects and advantages thereof will be apparent to. those- Fig; 1 isa side elevationof a grinding machine constructed in accordance with the invention, certain parts being broken. away and othersshown in section;

Fig. 2 is .an end elevation of the grindingma-' chine illustrated in .Fig. 1,. portions of the ma-.-

chine being broken away to more clearly reveal the construction. of. the novel feeding mecha nism;

feedin mechanism;

Fig. l is asideelevational viewof the present preferred embodiment of thenovel feeding-ma chanism of this. invention detached from the grinding machine;

Fig. 5 is a detached perspective view of the feed controlling. member of the. feeding mechanismillustrated in Fig. at;

Fig. 6 is a fragmentary elevational view-show ing the. regulatinguwheeland a portion of the; grinding wheelof the. machine and theirrmode of operation;

Figs. 7 is a side elevation view of anovel regulating. wheel dressing or truing means mounted upon a. grinding machine of. the type illustrated in Figs. 1-5 in place of the dressing means shown 1 therein; and

Fig. 8.is a sectionalview taken approximately" on the line 83 ofFig. 7 furtherillustrating the construction and operation of the novel regulating wheel dressing. means, portions being broken away to more clearly show the construction;

The illustrated grinding machine isof conventional design, except as hereinafter described,

and: is constructed similar to that disclosed in:

U. S. Patent No. 1,575,558, issued .to Einstein et a1;

on Marchcz, .1926. Such a machine comprises a main frame or. base. i0 having a substantially horizontal bed or top plate I! upon which-are supported suitable bearings for rotatabl mounting a grinding wheel l2. H' is also provided with dovetaledways. l3'upon which a regulating wheel supporting housing. I4

is slidably mounted, the base of this housing being provided with dovetal portions l5 cooperatingwith the Ways E3. The forward end of the regu'-' aithreaded shaft ll, the inner end of which is rotatablysecured within the support [4 and held The bed or top plate from longitudinal movement with respect thereto. The threads of the shaft I! pass through a stationary nut I3 supported by a bracket I9, mounted upon the base of the machine, and the outer end of the threaded shaft I7 is provided with a hand wheel or spider 28 by which the shaft I'i may be rotated.

The grinding wheel I2 is provided with a suitable housing or cover 2I and adjacent the grinding wheel is mounted a conventional truing or dressing device, generally designated 22. Mounted upon the forward portion of the regulating wheel support or housing IQ is a similar conventional truing or dressing device, generally designated 23. These devices 22 and 23 are employed in a conventional and well known manner for dressing or truing the periphery of the grinding wheel I2 and a portion of the periphery of the regula ing wheel I5.

As will be apparent from the drawings, and as is well known in the art, the grinding wheel I2 and regulating wheel i6 are both formed of suitable abrasive material, bonded together, and mounted upon arbors in a manner such that the two wheels are in substantial alignment and spaced apart sufiiciently to provide a work receiving throat 24 therebetween. The grinding wheel I2 is rotated in a clockwise direction by means of a motor 25 and suitable power transmission mechanism which is of conventional design and hence is not here illustrated. The regulating wheel I6 is likewise driven in a clockwise direction by conventional mechanism not shown which may comprise a separate electrical motor and power transmission means, or may comprise a transmission mechanism connected with the motor 25, it being understood that the regulating wheel EE is rotated at a speed different from that of the speed of rotation of the grinding wheel I? so that work placed within the work receiving throat is rotated therebetween during the material removing operation. Mechanism of this type is conventionally known as a center-less grinding machine because fixed centers are not provided for supporting the work 26, such as a stud, bolt or shaft, during material removing operation, the work being supported in such machine by the grinding and regulating wheels and by a longitudinally extending work rest 27. As is well known in the art, such a machine also includes a coolant or cutting fluid circulating system which is supplied to the workpiece 26 during the grinding operation and fiows by gravity into a trough or troughs from which it is recirculated by means of a pump 28 in a conventional manner.

In prior art centerless grinding machines it has been conventional to bodily move the regulating wheel towards and away from the grinding wheel to efiect feeding of the work, placed within the throat, into engagement with the grinding wheel during the grinding operation and to effect ejection of the work thereafter. It has also been conventional to employ a relatively fixed axis regulating wheel and various mechanical devices to eject the work from the throat after the grinding has been completed. Such a movement of the regulating wheel, or separate ejection devices, are no longer necessary when employing a regulating wheel constructed in accordance with this invention since the feeding during the grinding operation, and the subsequent ejection of the work, are effected solely by rotation of the regulating wheel. That is to say, once the regulating wheel support It has been initially adjusted, by

4 means of the threaded shaft I? and hand wheel or spider 25, to provide a work receiving throat 2 3 of a desired dimension, the regulating wheel support and the regulating wheel remain in this position throughout grinding operations.

In accordance with this invention the regulating wheel I6 is no longer of uniform radius throughout its circumference, but instead is pro.- vided with three separate and distinct peripheral portions or areas designated Ita, I61) and I80, respectively. As shown most clearly in Fig. 5, the portion Ita of the regulating wheel is of uniform radius and hence is concentric with the axis of the wheel. The portion lfib of the regulating wheel is eccentric with the greatest radius thereof equal to that of the concentric portion Ida. The portion I of the regulating wheel is formed by removing a portion of the periphery of th wheel to provide a recess which is interposed between the eccentric portion having the least radius and one end of the concentric portion. In the preferred embodiment, the portion Ito of the regulating wheel is chordal but it will be readily apparent the recesses of other configurations may be employed.

The initial adjustment of the regulating wheel, by means of the threaded shaft I1, is such that the work receiving throat has a width equal to that of the finished diameter of the work to be ground therein when the concentric portion I60 of the regulating wheel is adjacent the wheel I2. Hence, when the regulating wheel is positioned as shown in Fig. 5, the work receiving throat 24 has a width substantially greater than that of the finished work so that the latter can freely fall out of the work receiving throat as hereinafter described. The eccentric portion I61) of the regulating wheel is so formed that its smallest radius, when adjacent the grinding wheel 52 so as to define the work receiving throat therebetween, provides a throat of greater width than that of the diameter of the work to be ground therebetween.

With a regulating wheel thus constructed, a workpiece 28 is introduced into the work receiving throat 25 when the eccentric portion ISb is adjacent the grinding wheel I2, the workpiece then resting upon the upper edge of a work rest 21, the width of the throat then being such that the workpiece cannot fall from the work rest. As the regulating wheel continues to rotate in a clockwise direction the eccentric portion Ifib moves or feeds the workpiece 26 towards the grinding wheel I2 and, since the regulating wheel and grinding wheel are rotating at different speeds, the speed of the regulating Wheel preferably being less than that of the grinding wheel, the workpiece 26 is rotated therebetween and material is removed therefrom. The rate of material removal is governed by the speeds of the grinding and regulating wheels and by the eccentricity and the peripheral extent of the cocentric portion Ifib which are so selected that the diameter of the workpiece 25 is reduced to its desired final dimension by the time the regulating wheel has rotated to bring the concentric portion Ilia into the throat area.

The concentric portion I6a of the regulating wheel then cooperates with the grinding wheel I2 to finish or polish the work and as this concentric portion rotates beyond the throat, the recessed or chordal portion is moved thereinto. This recessed or chordal portion then provides sufiicient space for the workpiece 26 to fall freely by gravity from its position upon the top of the work-rest 21; The workpieceZG is assisted inthis movement" by the rotation ofthe grinding'wheel--.

l2 and, if desired; this m-ovement maybe further assisted 1 by-tapering or 'beveling the upper edge of-the-workrest-2'i as shownin Fig. 6: As soon asthe-recessed or chordal portion 160- ofthe regulatingwheelhas passed beyond the workroceivingth-roat 24-, and the-eccentric-portion lEb is againpositioned to form apart of the throat; a 10 n'ew'workpiecaisintroduced-into said throat-and the operation is repeated; Since the workpiece 1s fBdfiIltO" engagement with the grinding wheel during the grinding operation, and isremoved fromthe'work' receivingthroat after the grinding is completed, simply by rotationof the regulating wheel itself; the'delays interposed'by-prior mechanisms for performing these functions are removed" so that the'over-all time for agrinding v operation is -materially reduced. As the work-- pieces'drop out'of'the work receiving throat they may be collected in a suitable" removable pan device. for. sequentially" introducing" workpieces into the work receiving throat in timed relationship tothe rotation'of the regulating wheel. For the purpose ofdisclosing a' preferred embodiment of such a feeding mechanism; the apparatus is illustrated and described as adapted for feeding and" grindingworkpiecesin the form of headed cylindrical studs or bolts although itwill be 'understood that suitable conventional changeswi-ll permit the'feeding mechanisnrand' the regulating wheel of this invention to be'employed with workpieces of other types:

Asshowniin' the drawings, the work feeding' mean's'comprises a hopper 28 which is'here shown asbeing substantially rectangula'rwith thesides thereof. converging towards the bottom; Thishopper is preferably formed as two substantially symmetrical halves joined together in spaced re lationship, but maybe formed as one integral unit with an elongated'opening extending'substanti'ally medially thereof. Within such an opening or the'space provided between the two halves of the hopper, is ,pivotally mounteda'substantiallysector=shaped member'ZB which i'spiv otedat'one end 'thereofto' spaced ears or flanges 30*providedon'th'e lower side of the'hopper adjacent the forward edge thereof. This sectorshaped member 29, may be formed of two" plates connected together'in spaced relationship so as to'provide a' slot or'groove 3| therebetween, or may beformed'of asingle integral piece by bending, casting or the like. The'sector-shaped 'member-291's adapted to be 'rocked-froma position in which its upper edge'32, containing'the slot or groove'3l, is substantially coextensive with one side andbottom ofthe hopper to aposition as shown in'Fig; a; wherein the said sector extends well above the upper'edge of the hopper. This is effected by allowing "the lower edge of the sector plate to extend through the bottom of the hopper and by engaging the-said lower edge with a'roller '33 provided uponthe'end'of-a crank arm 3 i 'which is, in-turn, rotatablymounted upon a shaft This shaft "SE -is supported upon a por tionof a bracket-or standard 35 which also serves to supportthe hopper 28.- The shaft-35 is provided with a sprocket wheel 31 which is driven bya motor 38. operating through a gear reduction unit 39 and sprocket wheel All to drive a chain t! passing about the sprocket wheels 3? and it]. Hence, the crank arm 3 i-is rotated and during each rotation thereofthe roller 33 engages the lower edge of thesector 29 and elevatesthe latter to a position shown in Fig. 4, the sector dropping by gravity to its lowermost position as the roller 33' i moved from under the sector. It will be apparent, therefore, that when the hopper 28 is supplied'with headed cylindrical objects such as studs, bolt or the like, they will gravitate to the lower portion of the hopper, and as the sector 29- is periodically raised a portion of these-workpieces will be elevated in the manner shown in Fig. i. That i to say, the shanks of these workpieces will drop into the groove of the sector andthe heads thereof will ride upon the edges 32 of the sector. Instead of sprocket wheels 37 and ltand chain ill;

a pulley and belt drive maybe employed between the gear reduction unit- 39 and shaft 35.

When the workpieces 26 are thus elevated by the sector 25 they will slide along'the upper surface or edges of the sec-tor plate and thereby pass out of the hopper adjacent the point of pivot of the sector plateand will move by gravity down inclined track; generally designated 42, until they are-stopped-by a rocking feed controlling member 6-3. Thisinclined track 4200mprises pairs of spaced side plates, such as 44,

' which are connected-together in predetermined spaced relationship sufiicient to allow the shanks of the workpieces 2% to extend therebetween with the heads of the workpieces resting upon the upper edges of the-plates; The plates 44 are held in this spaced relationship by means of upstanding brackets or plates 35 attached thereto and extending thereabove; the upper ends of these plates or brackets 55 being connected by threaded shafts or bolts 46 provided withnuts 41 so thatthe spacing of the plates or members M maybe adjusted to accommodate workpieces of difierent diameter. Two of the upstanding plates or brackets t5are further connected to a side plate :8 which is also connected to a portion of thebracket or support 36 for the hopper 28.

The bracket 36 is provided with two spaced downwardly extending legs 49 and 50. The lower end of the leg 55 is provided with an elongated horizontally extending slot 5!, and this leg 50 is supported by apair of vertically spaced standards or plates 52 between which the leg 50 is received and through which extends a bolt or machine screw 53, the latter also extending through the slot 5'! in the leg 5!]. Legsdil and 50 of the support 3d are connected by a horizontally extending plate or bar 5d, one end of which is attached to the leg 56 and the vertical plates or supports 52 by the bolt or screw 53 -and'the other end of which is secured to the leg 69 by a bolt or machine screw 55 passing through a slotted opening in the lower end of the leg 49. The upper ends of the vertical supports or plates 52 are provided with horizontal extensions 56 to which the horizontal plate 5 3 is additionally connected by means of a screw or bolt 51 to hold the parts rigidly and prevent rocking movement. The slots in the arms or legs 49 and 513 of the bracket or support" 36 provide for adjustment between the parts for initial assembly. Instead of'being a'separate member, the plate Simay, if desired;

be welded or brazed to the arms or legs 49, 50 of support 36. The lower ends of the upstanding plates or brackets 52 are secured to a base plate 58 in any suitable manner.

Adjacent the forward edges of the plates or brackets 52 the plate 58 is provided with an upstanding block or support 59, and spaced forwardly thereof and aligned therewith is a second block or support $6 likewise secured to the base plate 58. The upper ends of these blocks or supports 58 and 89 are bifurcated and receive therebetween a horizontally elongated portion 6| of the work rest or support 21. As shown, the work rest 21 comprises an upstanding flange substantially centrally of the portion 6| and formed integrally therewith, the portion 6| being clamped to the blocks or supports 59 and 60 by bolts or screws 62 and 63. Adjustment of the work rest between the supports or blocks 59 and Eli may be eiiected by providing elongated slots in the portion 6| through which the bolts or screws 62 and 63 pass, or the work rest portion 21 may be made separable from the horizontal portion 6! and adjustable relative thereto in the well known manner. Also, if desired, the supports 59, 60 need not be made as integral blocks but can be formed as two spaced plates secured together in suitable manner. Instead of securing supporting plates 52 directly at the base plate 58, or in addition to such securing, a plate or plates 3 2 may be secured between the plates 52 by a bolt or bolts 65 with a portion of the plate or plates 64 extending beyond the plates 52 and welded or otherwise secured to the block or support 59.

A vertically extending plate 65 is bolted to the forward edge of the block or support 65 and extends upwardly adjacent the downwardly curved forward end of the track 42 as shown in Fig. i. The upper end of this plate or support 66 pivotally mounts the previously mentioned rocking feed controlling member 43 which, as shown in Figs. 3 and 5, is substantially U-shaped with the legs thereof disposed on either side of the forward edge of the track 42. One leg of the rocking member 33 is provided with an inwardly directed pin 68 which is adapted to extend through an opening 65 provided in the adjacent plate or side 64 of the track and when so extending, the pin 68 engages the workpieces 26 moving downwardly along the track 42 to retain the track 32 so as to normally rock the member 1 43 to the position shown in Fig. 3. This leg 67a is likewise provided with an inwardly directed pin 68a adapted to extend through an opening, similar to the opening 69, in the side of the track to engage the workpieces moving therethrough.

The pins 68 and 68a are so spaced and the construction is such that, when the spring urges the member 43 to the position shown in Fig. 3, the pin 68a projects into the track 42 and holds back the workpieces 26 therein. When the -member 43 is rocked against the tension of the pring .6 to the position as shown in Fig. 4. the pin 68 is projected into the path of the lowermost work piece while the pin 68a is withdrawn from the path of the workpieces. When the member 43 is again rocked under the action of the spring 78, the pin 68 is withdrawn from the path of the lowermost workpiece and the pin 88a moves into the track 42 between the lowermost workpiece and the next workpiece. Hence, the lowermost 8 workpiece is now free to drop into an opening provided in the upper surface of a guide member H connected with the vertical supoprt 66. This guide member H has its opening substantially aligned with the work rest 21 but with the bottom of the opening in the member H spaced vertically above the upper edge of the work rest 21 slightly as indicated in Fig. 4, the workpiece positioned in the member H being projected onto the work rest in timed relation with the rotation of the regulating wheel as hereinafter described.

In addition to the side members 44, the track 42 also includes a top strap or member 12 which conforms with the upper edges of the side members 44 but is held in spaced relationship thereabove by suitable brackets 73 connected with side members 44 of the track, the brackets being adjustable to enable the elevation of the member 12 to be adjusted. This member 12 guides the upper ends of the workpieces in their movement along the track 42 and the workpieces 26 are further guided upon their entrance into the track 42 by an eccentrically mounted roller 14 rockably supported upon the hopper 28 at the point of emergence of the workpieces from the groove in the sector 29, the action being such that the roller '14 depresses the heads of the workpieces into engagement with the upper edges of the side members 44 of the track so that the workpieces will feed freely therethrough and will not jam against the cover or strap 12. In order to prevent workpieces from lodging behind and under the sector 29 the rear portion of the slot or opening in the hopper is filled by an adjustable member 75 pivoted to the hopper adjacent the rear edge thereof and held in adjusted position by a screw 16, or the like, passing through an elongated slot in the member 15 and through downwardly projecting ears ll carried by the hopper.

The hopper 28, track 52, work rest 21, and the actuating mechanism for the workpieces, about to be described, are adapted to be mounted as a unit upon a conventional grindin machine by attaching the plate 58 to the bed H of the machine in place of the usual work rest provided thereon.

This may be effected by a plurality of bolts or other attaching means, the plate 58 being so mounted that the work rest 21 occupies substantially the same position as the conventional work rest provided in such a machine.

Pivotally mounted upon the plate 58, at a point spaced forwardly of the support 56, is a rocking actuating arm 18 which may be formed as two spaced members connected together by suitable spacers. Between the ends of the rocking member 78 is pivotally mounted a block 19. This block has a transversely extending bore through which an actuating rod as extends, the rod 80 being provided with collars SI and 32 which are connected to the rod on opposite sides of the pivoted block 19. One end of this rod 80 extends through an opening in the supporting plate 66 and is adapted to contact the head or" a workpiece 26 resting in the member ii. The construction is such that as the arm or member 78 is rocked, from the full-line position shown in Fig. 4 to the broken-line position shown therein, the rod 80 strikes the workpiece 28 and forces the latter forwardl into the work receivin throat 24 so that the workpiece rests upon the work rest 21, the movement of the workpiece in this direction being limited by an abutment member 83. This abutment member is substantially aligned with the workpiece when the latter is on the work rest and the abutment member is supported upon the members 52 by passing through a collar 84 connected with the members 52, the position of the abutment 83 being adjustable by sliding the latter through the collar 84 to the desired position and then looking the abutment member within the collar by means of a set screw 85.

The rocking member or arm 18 is moved, as just described, by means of a tension spring 86, one end of which is connected at a point adjacent the top of the rocking member 18, the other end of the spring being connected to a fixed part of the track 42 such as one of the transversely extending bolts or shafts 46. The rocking member i8 is moved in the opposite direction, against the action of the spring 86, by a face cam 81 connected concentrically with the regulating wheel E6, the face of the cam 8! bearing upon a cam roller 88 rotatably supported upon the rocking arm l8, the said roller being positioned so that its axis lies substantially upon a plane passing through a diameter of the regulating wheel. The cam 81 comprises a high or lobe portion 87a and a lower or dwell portion 8'51), and the cam is initially so adjusted relative to the regulating wheel that the low portion 8% of the cam allows the rod to move a workpiece 26 into the work receiving throat after the recessed or chordal portion I60 of the regulating wheel has just passed the throat, the high portion 81a of the cam being disposed so that the arm 18 is rocked to its full-line position while a workpiece is being ground within the throat and during the passage of the recessed or chordal portion Mic of the regulating wheel past the throat at which time the workpiece is discharged therefrom.

In addition to operating the rod 89 to feed a new workpiece into the work receiving throat of the grinding machine, the rocking arm '53 also actuates the rocking member 43 to control the movement of the workpieces from the track d2 into the opening in the supporting member M. This is effected by virtue of the fact that the arm i8 strikes the rocking member 43 when the arm 18 is in its broken-line position as shown in Fig. 4. This rocks the member 43 to move the pin 88 into the path of the lowermost workpiece and to withdraw the pin 68a, as previously described, while the rod 80 is projecting a workpiece into the work receiving throat. When the cam 81 moves the member 18 to its full-line position as shown in Fig. l, the member 43 is again rocked to the position as shown in Fig. 3, by the spring 10, thus allowing a single pin to drop from the track 42 into the opening in the member H in position to be actuated by the rod 88 when the latter is again moved forwardly under the action of the spring 85 as permitted by the low portion 81b of the cam. Hence, workpieces are sequentially fed in a longitudinal direction into the work receiving throat where they are initially supported by the work rest 21 and are then fed into grinding engagement with the grinding wheel I2 by the regulating wheel [6. The recessed or chordal portion Ific of the latter permits the workpieces to drop from the work receiving throat when the grinding operation is complete, the cam carried by the wheel operating the feeding mechanism to position a new workpiece within the work receiving throat when the grinding operation on the preceding workpiece is complete and the regulating wheel has rotated to bring the eccentric portion adja-- cent the work rest.

It will be observed that, in the illustrated embodiment, the rod 80 does not hold the work- 10 pieces in the work receiving throat but simply feeds them therein and is retracted from engagement with the workpieces during the grinding operation. Where the workpieces are headed studs, as shown, it is not absolutely necessary that an abutment member 83 be provided since the parts may be so positioned that the head of the workpiece engages the edge of the work rest to limit its longitudinal movement into the work receiving throat. However, the provision of an abutment member 83 is advantageous because it insures that workpieces cannot be projected too far within the work receiving throat as might occur in certain instances where the head of the workpiece did not properly engage the work rest.

If it be desired to terminate feeding of workpieces this can be readily accomplished in the illustrated machine without stopping the motor 38 by simply dropping a latch or abutment'member 88 into the path of an adjustable collar 89 provided upon the threaded outer end ofthe shaft 89, this latch or abutment member being pivotally mounted upon a vertical support 99 attached to the base plate 58. By so dropping the latch or abutment member 88, the latter engages the collar 89 preventing the spring 86 from mov ing the rod to feed a new workpiece into the work receiving throat. Feeding operation may be resumed by simply lifting the latch or abutment member 88 from engagement with the collar 89. Operation of the entire machine may be readily terminated by the usual electrical circuit and control box since the motor 25 for the grinding wheel 12, the motor for the regulating wheel, if the latter has a separate motor, andthe motor 38 for the feeding mechanism are connected in a suitable circuit controlled by start and stop buttons 9| and 92 respectively, mounted at a convenient point upon the base of the machine. If desired, a separate switch may be provided for the motor 38 of the feeding mechanism in order that feeding of workpieces from the hopper may be terminated without stopping the en tire machine. The grinding machine is illustrated in Figs. 1 to 6 as provided with a regulating wheel truing or dressing attachment 23 of conventional design. It will be readily apparent, however, that the entire periphery of the novel regulating wheel of this invention cannot be dressed by such an attachment. However, the concentric portion [6a of the regulating wheel can be so dressed or trued and since it is this portion which controls the finished diameter of the work, it is the portion which would normally'require the most frequent truing or dressing. The truing device 23 will cooperate with this portion of the wheel in the conventional manner which is well understood and, hence, need not be described in detail. If other portions of the wheel should require dressing or truing itis ordinarily necessary, when a conventional truing or dressing device is em ployed, to remove the wheel from the machine to efifect such operations. It should be observed, however, that frequent dressing of the portions lfib and I60 of the regulating wheel will not be necessary and satisfactory operation is obtained over relatively long periods of use by simply dressing the portion Mia and adjusting the width of the work receiving throat by means of a hand wheel or spider 28, after the said dressing has been accomplished, to maintain the finished dimension of the workpieces at the desired value.

In order to obviate the necessity for removing the regulating wheel Hi from the machine to efi'ect dressing or truing of the eccentric portion ltb, the conventional dressing means 23 may be replaced by the novel truing or dressing means 23' illustrated in Figs. 7 and 8 of the drawings. This means comprises the usual housing 95 which is movably mounted upon dovetail ways 96 provided upon the slotted forward portion of the regulating wheel housing It, the housing 95 being movable transversely of the regulating wheel by the conventional handwheel 91 and screw 98 or by hydraulic means, as is well known in the art. A sleeve 99 is slidably mounted in a substantially vertical bore in the housing 95, and a diamond holding bar N39 is slidably disposed within the sleeve 98. The lower end of the diamond holder bar is provided with dovetail Ways for adjustably mounting the diamond support it! with the diamond I92 projecting from the lower surface of the support for engagement with the regulating wheel l6 when this wheel is to be dressed or trued.

The upper end of the diamond holder bar 199 is provided with a threaded bore in its upper end within which is screwed the lower end of an adjusting screw IE3. The upper end of this screw is provided with a graduated sleeve I94 having a handle I95 extending transversely therethrough and the screw I03 is rotatably mounted, but held against longitudinal displacement, by a collar I06 mounted in the upper end of the sleeve 99. The diamond holder bar we is held from rotation by means of a longitudinal extending groove and a cooperating gib I91. The construction is such that turning the handle E95 and the graduated sleeve I04, causes the diamond holder bar to move longitudinally relative to the sleeve 99 thereby adjusting the diamond I92 with respect to the regulating wheel [6.

Mounted upon the regulating wheel spindle to rotate therewith is a cam I68 which has a concentric portion 198a, an eccentric portion [08b and an irregular curved portion 598s. The lower end of the sleeve 99 is provided with a transversely extending bracket member 659 provided with an elongated cam follower Hi3 which rides upon the cam N38. The cam follower is urged into engagement with the cam by a compression spring Hi acting between the housing 95 and a bracket H2 fixed to the sleeve 99 and having a portion projecting through an opening in the housing 95. The bracket H2 is also provided with a clamping means including a screw H3 which extends through an opening in the housing and is adapted to clamp the sleeve 99 and the diamond holding bar 90 together. The construction is such that, as the regulating wheel I6 and cam I98 are rotated, the cam follower H causes the sleeve 99 and the diamond holder bar to be moved so that the diamond m2 accurately trues or dresses the eccentric and concentric portions of the regulating wheel to the proper curvature, the portion i980 of the cam moving the diamond away from the regulating wheel while the recessed portion of the latter is passing under the former. This prevents injury to the corners of the regulating wheel formed by intersection of the chordal portion of th wheel with the concentric and eccentric portions there of, while permitting accurate dressing of the concentric and eccentric portions immediately adjacent the corners. Since the recessed portion of the regulating wheel simply controls the discharge of a workpiece after being ground, it does not need to be dressed.

During the time when the diamond I92 is contacting the regulating Wheel, under control of the cam 198, the housing 95, and hence the diamond, are traversed with respect to the regulating wheel by means of the handwheel 9'! and screw 98, or by conventional hydraulically operated means, so that the entire width of the regulating wheel is dressed or trued. It will be observed that the cam follower Hi1 has a wide face so that it will remain in contact with the cam while the diamond is being traversed over the entire width of the regulating wheel. Preferably, the width of the cam follower is sufiicient so that the diamond may be moved beyond the regulator wheel after the dressing or truing of the latter is completed.

The diamond may also be disengaged from the regulating wheel by operation of the handle 5M which is pivoted to the housing and operates in the conventional manner to elevate or lower the sleeve 99. The housing 95 is also provided with a clamping means including a screw l 15 which cooperates with the sleeve 99 to clamp the latter to the housing 95 to hold the diamond from engagement with the regulating wheel after the handle H4 has been operated to raise the diamond.

While the regulating wheel is here shown as having its axis substantially parallel with the axis of the grinding wheel 52, it will be apparent that the axes of these wheels may be disposed at a slight angle with respect to each other, if desired, for grinding tapered workpieces as is well known in the art and this will not interfere with the operation of the device.

It is believed that the mechanism of this invention will now be readily apparent from the above described embodiments. rized, the operation is as follows:

Workpieces 25 to be ground are supplied to the hopper 28 and the start button 91 is actuated. Actuation of button 9! starts the motor or motors for rotating the grinding wheel and regulating wheel. If the feeding motor 38 is wired for control by the buttons 9| and 92, it also starts when the button 95 is actuated. If a separate switch is provided for the feeding motor 38 this switch is preferably actuated after the actuation of the button 3!. As the motor 38 rotates it drives the chain or belt 4 l, which in turn rotates the crank Briefly summaarm 34, so that the roller 33 on the latter rocks the sector member 29 within the hopper 28. Each time the sector member 29 is raised, to the position as indicated in Fig. 4, certain of the workpieces within the hopper will be lifted thereby since the converging configuration of the hopper and the stirring action of the sector member aligns the workpieces so that the shanks of at least some of the workpieces drop into the groove 3! in the sector member each time it is actuated. The workpieces which are so positioned within the groove 3! during each rocking motion of the sector member 29, move by gravity from the latter when it is elevated and passed into the track 12, the eccentrically mounted weight member M insuring that the heads of all of the workpieces are suitably positioned as they move into the track.

As the workpieces move downwardly through the track 22 under the influence of gravity, the lowermost workpiece engages the pin 680, until the regulating wheel has rotated sufiiciently to cause the low part 8% of the cam 81 to come adjacent the roller 88. This operation of the cam enables the arm or member 18 to rock to its broken-line position as shown in Fig. 4 under influence of the spring 85 and when so rocked, the arm or member it strikes. the rocking member d3 moving the pin 68a from engagement with the. lowermost workpiece and bringing the pin 68 into the path thereof. When the high point of the cam 81a again moves the rocking arm or member E8 to its rearmost position as shown in Fig. 4, the member 43 rocks under the influence of the spring ll? thereby moving the pin 68 from engagement with the lowermost workpiece and bringing the pin 86a into the path of the next succeeding workpiece.

The lowermost workpiece thus freed, drops into the opening of the support member H and hence, when the rocking member l8 again moves to its broken-line position as shown in Fig. 4, the rod 80 engages the workpiece so positioned upon the member li, forcing the latter into the work receiving throat between the grinding and regulating wheels with the workpiece resting upon the work rest 21. The device is so timed that when the workpiece is thus projected or positioned, the eccentric portion of the regulating Wheel will be adjacent the work receiving throat so that the said workpiece cannot drop therefrom.

As the regulating wheel continues to rotate, the eccentric portion 55b thereof feeds the workpiece against the grinding wheel and the joint action of the grinding and regulating wheels rotates the workpiece and removes material therefrom, this action continuing until the concentric portion ltd of the regulating wheel is adjacent the work receiving throat. At this time no further feeding of the work against the grinding" wheel occurs but the continued action of the regulating and grinding wheels is effective to finish or polish the workpiece to the desired final dimensions. Continued rotation of the regulating wheel then brings the recessed or chordal portion lfic. adjacent the work receiving throat and the workpiece 26 then drops from its position on the work rest 2?, being assisted in this action by the rotation of the grinding wheel. After the recessed or chordal portion has passed the work receiving throat and the eccentric portion Nib is again adjacent thereto, the cam 8'! will have been moved to a position allowing the rocking arm or member is to again feed a new workpiece into the work receiving throat, it being understood that the high point in the cam 8'! had previously withdrawn the rod 88 from engagement with the workpiece during the grinding operation upon the workpiece and during this backward movement of the rocking member 18, the member 43 was actuated by the Spring 10 to drop another workpiece upon the supporting member 1! into position to be fed into the work receiving throat by the rod Bil. Hence workpieces are sequentially fed into the work receiving throat where the regulating wheel feeds them against the grinding wheel and the two wheels cooperate to grind the work to a finished diameter, the regulating wheels continued rotation thereafter causing discharge or rejection of the finished workpiece. Ihis operation continues so long as workpieces are present in the hopper 2B or the track 42.

While the present preferred embodiment of the invention and a modification thereof have been described and illustrated in considerable detail it will be readily apparent that numerous variations and modifications may be made therein without departing from the spirit of the invention. Thus, the concentric portion of the regulating wheel need not be provided in certain in- 14 stances, the periphery of this wheel then consisting only of recessed and eccentric portions. Moreover, while the invention has been disclosed as comprising a novel regulating wheel, feeding device, and a truing device it will be readily apparent that any of these may be used without the other if so desired, although the maximum eficiency of the machine is achieved when all are used together. Other variations and adaptations of the mechanism will be readily apparent to those skilled in the art and therefore the invention is not to be considered as limited to the exact details herein illustrated and described but only as required by the spirit and scope of the appended claims. 1

Having thus described the invention, we claim:

1. A centerless grinder comprising opposed rotatable grinding and regulating wheels mounted in spaced relationship to form a workpiece receiving throat therebetween, the said regulating wheel having a segment of its periphery removed to provide a recessed portion and the remainder of its periphery including an eccentric portion with the greatest radius thereof being such that when disposed in the line passing through the centers of the grinding and regulating wheels to form one side of said workpiece receiving throat the width of the latter is substantially equal to the desired final diameter of the workpieces, a supply hopper for receiving elongated workpieces with their axes extending in diverse and nonordered directions, an inclined track having its upper end adjacent said hopper and its lower end adjacent said throat, means communicating with the upper end of said track and movable through said hopper to periodically remove workpieces from said hopper in a predetermined ordered. arrangement and to introduce said removed workpieces onto the upperend of said inclined track in the ordered arrangement, a stationary support aligned with said throat and positioned for receiving a workpiece from the lower end of said track, and means operated in timed relationship with said regulating wheel to control sequential delivery of said workpieces from said track onto said support and to axially move each workpiece from said support into said throat whereupon the eccentric portion of the regulating wheel progressively feeds the workpiece in said throat towards the grinding wheel for effecting material removal and the recessed portion of the regulating wheel allows the workpiece to drop by gravity from its position within the said throat after the grinding is completed.

2. A centerless grinding machine comprising opposed rotatable grinding and regulating wheels mounted in spaced relationship to form a workpiece receiving throat therebetween, a supply hopper for receiving elongated workpieces with their axes extending in diverse and non-ordered directions, an inclined track having its upper end adjacent said hopper and its lower end adjacent said throat, means communicating with the upper end of said track and movable through said hopper to periodically remove workpieces from said hopper in a predetermined ordered arrangement and to introduce the removed workpieces into the upper end of an inclined track in ordered arrangement, means adjacent the lower end of said track operable to control oneat-a-time delivery of workpieces therefrom, means to move a delivered workpiece axially into said throat, and means operated in timed relationship with the rotation of said regulating 15 wheel to efiect sequential operation of said control means and said workpiece moving means.

3. A workpiece feeding mechanism for a centerless grinding machine having opposed rotatable grinding and regulating wheels mounted in spaced relationship to form a workpiece receiving throat therebetween, the said mechanism comprising a supply hopper for receiving elongated workpieces with their axes extending in non-ordered directions, an inclined track having its upper end in communication with said hopper and its lower end disposed adjacent said throat, the said track being adapted to convey workpieces in single file order from the said hopper, means for removing workpieces from said hopper in single file ordered arrangement and for introducing them into the upper end of said inclined track, a stationary workpiece sup-port spaced below the lower end of said track in alignment with the said throat, means adjacent the lower end of said inclined track adapted to be sequentially operated to control delivery of the workpieces one-at-a-time from said track to said support, reciprocating means for axially moving a workpiece from said support into said throat, and a single rockably mounted member cooperating with reciprocating means and said means controlling delivery of workpieces to said support to effect sequential operation thereof.

4. A workpiece feeding mechanism for a centerless grinding machine having opposed rotatable grinding and regulating wheels mounted in spaced relationship to form a workpiece receiving throat therebetween, the said mechanism comprising a supply hopper for receiving elongated workpieces with their axes extending in non-ordered directions, an inclined track having its upper end adjacent said hopper and its lower end disposed adjacent said throat, the said track being adapted to convey workpieces in single file order from the said hopper, means in communication with the upper end of said track and movable through said hopper to periodically remove workpieces from said hopper in single file ordered arrangement and to introduce the said removed workpieces into the upper end of said inclined track in ordered arrangement, a stationary workpiece support spaced below the lower end of said track in alignment with the said throat, a member movable transversely of said track adjacent the lower end thereof to control delivery of the l 6 workpieces from said track to said support, a member mounted for reciprocation over said support and adapted to engage a workpiece thereon and move the latter axially into said throat, and means for sequentially operating said movable member and said reciprocable member.

5. A workpiece feeding mechanism for a centerless grinding machine having opposed rotatable grinding and regulating wheels mounted in spaced relationship to form a workpiece receiving throat therebetween, the said mechanism comprising a supply hopper for receiving elongated workpieces with their axes extending in non-ordered directions, an inclined track having its upper end in communication with said hopper and its lower end disposed adjacent said throat, the said track being adapted to convey workpieces in single file order from the said hopper, means for removing workpieces from said hopper in single file ordered arrangement and for introducing them into the upper end of said inclined track, a stationary workpiece support spaced below the lower end of said track in alignment with the said throat, a member movable transversely of said track adjacent the lower end thereof to control delivery of the workpieces from said track to said support, a member mounted for reciprocation over said support and adapted to engage a workpiece thereon and move the latter axially into said throat, and a single rockable member cooperating with said movable member and said reciprocable member to effect sequential operation thereof.

BERNARD P. APPEL. JOSEPH F. KLUKAN.

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

UNITED STATES PATENTS Number Name Date 590,463 Plopper Sept. 21, 1897 1,814,279 Binns July 14:, 1931 1,828,596 Danly Oct. 20, 1931 1,847,466 Binns Mar. 1, 1932 1,850,054 Strickland et al. Mar. 15, 1932 1,932,952 Binns Oct. 31, 1933 2,025,714 Binns Dec. 31, 1935 2,091,655 Scrivener Aug. 31, 1937

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