US1737852A - Centerless grinding machine - Google Patents

Description

Dec. 3, 1929. r F. M. KERN 1,737,352

CENTERLESS GRINDING MACHINE` Original Filed April 1, 1926 3 ShSBtS-Sheet 1 fred M.}(ern EM meg@ Dec. 3, 1929. F. M. KERN 1,737,852

CENTERLESS GRINDING MACHINE Original Filed April 1. 1926 3 Sheets-Sheet 2 Jed M. Kern l tkouwq Dec. 3, 1929. F, M. KERN 117375852 CENTERLESS GRINDING 'UACHINE Original Filed April il, 1926 3 Sheets-Sheet 3 gmc/nto@ red Mjfern and! was# Patented 3, 19294 UNITED STATES PATENT OFFICE FRED M. KERN, l' DETBOIT,`IIGHIGAN, ASBIGNOR, BY ASSIGNMENTS, T0 Cuff CINNATI GRINDERS INCBPOBATED, 0l' CINCINNATI, OHIl A C OBPVORATlON' 0F OHIO aannames Gnnmnm Application led April 1, 1929, Serial lo. 98,95@ Renewed April 5, 1999.

tated grinding wheel and'a slowly rotated work regulating wheel.-

Heretofore, centerless grinding machines have been provided in which a work piece has beenpositioned for res ective grinding and rotation between a rapid y rotated grinding wheel and a slowly rotated work regulating wheel having its axis skewed at a Vslight angle to the axis of the grinding wheel (where both wheels are of the perip eral type)A so as to propel the work axially past and between' the wheels. Such a machine is not adapted for grindingj c lindrical work of special form, such as wor having a shoulder or enlargement thereon, since the latter prevents complete passage of the work axially past the wheels.

It is an object of the invention, therefore, to provide a centerless grinding machine for grinding such s cial shapes of cylindrical work economica y and accurately upon a commercial production basis.

It is a further object to provide a pipe or the like in a ceteiless grinding machine for supplying grinding fluid upon the work piece during the grinding operation which is constructed and arran ed to convey the grinding fluid in the most. a vantageous manner upon the Vwork regardless of any changes in the adjustments of the'machine required on account of wear of the rinding wheel or so that 4work of different sizes may be ground.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts as will be exemplified in the structure to be hereinafter described and the scope of the application of which will be indicated in the following claims.

machine as viewed from above in Fig. 1' the grindin wheel and certain other parts bein remove in order to show certain features o the construction more clearly;

- Fig. 3 is a detail view of the rack for carry ing the mounting for the work positioning4 member;

Fig. 4 is a detail view of the mounting for the positioning member;

' Fig. 5 is a side elevational view of a portion of the machine of Fig. 1 and shows certain parts in section as seen along the line 5--5 of Fig. 2;

Fig. 6 is an elevational view, partly in section of the eccentric shaft which supports the mointing for the work positioning member; an

Fig. 7 is a diagrammatic view of a machine in which the Wheels are disposed in substantially the same horizontal plane and which embodies certain features of the invention. A

' Similar reference characters refer to similar arts throughout the several views of the rawngs.

Referring now to the drawings I have shown in Figs. 1 to 6 a machine embodying a preferred form of the invention com rising a frame 10 (Fig.'1) having a spind e11V mounted at an upper portion thereof for rotation. A grinding wheel 12 is mounted on the spindle end is rotated rapidly and hence at a suitable inding speed from Vany suitable source o power by means of a belt 13 passing over a pulley 14 secured upon the spindle 11. A column 15 is mounted for vertical movement in a lower front but referably hollow cylindrical portion o frame and is prevented from turning therein by a key 17 en aging a groove 18 in the column. A spin e 19 carrying a regulating wheel 20 is mounted for rotation in suitable bearings (not shown) within the bearin casing 21 upontlie support 22 inte ral with or suitably securedl uponthe top o the column 15, and -ma be rotated relatively slowly from any suitab e source of power, such as a motor 23 connected dii-eetl .with a shaft 24 carrying a worm 25 whic en es a worm wheel 26 secured uponI the spin le i9. y The two wheels are rotated in the directions indicated the by the arrows in Fig. 1 and it will be noted that the adjacent operative surfaces of the two'wheels are thus made to travel in opposite directions relative to a point therebetween; the regulating wheel serves to control the rotation of work pieces of round section interposed between the two wheels, the grinding wheel performing a grinding operation thereon during such rotation.

An upwardly projecting bracket 27, formed preferably asan integral part of the column 15, is provided with vertically eX- tending slideways 28 for receiving a slide 29 which may be adjusted vertically by turning a shaft 30 (see also Fig. 5) mounted inthe bracket 27 and carrying a pinion 31 engaging a rack 32 on the sllde 29. A water pan 33 is secured to the eolumlr 15 by means 'of bolts 34 passing from the column into the support 22. The regulating wheel 2O and the bracket 27, as well as the water pan 33, may be moved vertically by turning a screw shaft 35, which is mounted (see Fig. 1) so as to prevent longitudinal movement in a bearing (not shown) in the column 15 and is arranged to engage a threaded hole 36 in a vboss 37 secured to or integral with the frame l0. The screw shaft 35 may be turned by means of a hand wheel (not shown) secured upon a shaft 38 carrying a worm 39 which engages a'worm wheel 4() mounted upon `the screw shaft 35.

In order that the work may be held in operative contact with the grinding wheel and work regulating wheel while being ground to a predetermined si`ze by the former and rotated by the latter, I provide a work positioning or movable work holding member adapted to move the work into the grinding throat between the wheels and preferably in a direction opposed to that in which the thrust of the rinding wheel is exerted thereon. Thus, re erring to Fig. 1, the operative surface of the grinding wheel 12, adjacent the regulating wheel 20, will be seen to move in a direction from the left to the right, and I achieve many advantages by causing the work positioning member to move the work piece into operative relation to the two wheels in a direction from the right to the left as viewed in Fig. 1 and hence in a direction opposed to that in which the thrust of the grindino wheel is exerted on the work. A suitable and preferred form of mechanism for this purpose may include a mounting 43 (see Fig. 4) supported fromthe slide 29 (Figs. 3 and 5) by a shaft 44 mounted for rotation in bearings 45 thereon. The shaft v44 is provided with eccentric portions 46 (Fig. 6) integral with or otherwise appropriately secured thereto, which are adapted to engage and rotate within bearings 47 (Fig. 4) in the mounting 43; A work moving member 48 (Figs. 1, 2 and 5) is adjustably se` cured upon the projecting arms 49 (Fig. 4)

on the mounting 43 \`by means of bolts 50 passing through the holes 5l in each arm. The mounting 43 is provided with an L shaped arm 52 extending rearwardly therefrom and projecting thrpugh a slot (see Fig. 5) in the bracket 27. The arm 52 has a'bearing plate 53 adapted to slidably engage a bearing plate 54 on the bracket 27. The extent of the movement of. the member 48 is limited by an adjust-able stop screw 55 threaded into a lug 56 (Fig. 4) on the *arm 52, the stop screw being arranged to engage the bracket 27. The mounting 43 is provided with a forwardly projecting guard 57 (Fig. 5) and an upwardly projecting guard 58, the latter being adapted for movement beneath a cover 59 extending downwardly and out-V wardlyl from the slide 29. The bearing plate 53 is held in contact with the bearing plate 54 by means of a plunger 60 pressed upwardly by means vof a spring 61 surrounding a reduced .portion of the plunger in a hole 62 in a lug 63 extending from the bracket 27 A bearing plug G4, through which the 'reduced portion of the plunger 60 passes, engagesa threaded portion of the hole 62 so as to press against the spring 61 and thus permit of ad'-,

justing the compression on the spring.

lVhen the work moving member 48 is withdrawn (in a direction to the rightas viewed in Fig. l), the finished work may be discharged. A preferred form of device for this purpose may include a reciprocating plunger comprising a hollow casing 65 (Fig. 2)l adjustably mounted upon the Water pan 33 by means of bolts G6 passing through a slot 67 in a downwardly depending bracket 68 integral with the casing 65. A hollow piston 69 is slidably mounted within the casing G5 and normally is held in the position shown in Fig. 2 by a spring 70 secured at one end to a 'pin 71 in the piston 69 and at the other end to a pin 72 in the casing 65. A pusher rod 73 is secured at the forward end of the piston 69 by a ,clamp 74 and bolt 75. The other end of the piston 69 is provided with an ear 76 which project-s through a slot in the hollow casing 65 and is connected, in the device illustrated, to one end of a rope 77 passing around a pulley 78 mounted upon an arm 79 projecting from and integral with the casing 65. The rope l77 is connected at its other end with a manually operated device which may control the operation of the plunger as will be more clearly described hereinafter.

The mounting 43 for the member 4'8 and the reciprocating plungery may be actuated by the same or different devicesJ which may be controlled manually or by power through by a nut 90. The other end of the 4arm 88 is secured to one end of the rope 77. A link 91 is pivotally mounted at'one end to the arm 88 and is provided near its other end with a slot 92 adapted to engage an upwardly projecting pin 93 in the lever 85. Arod 94 is,

pivotally secured at one end u on a stud 95 secured in a downwardl an forwardly' extending crank arm 96 Figs. 1f and 2).

The other end of the rod 94 is pivotally l mounted upon a stud 97 secured in a bifurl cated end of a bolt 98 which is pivotally mounted on the lever 85 and is secured thereon by means of a nut 99. The crank arm 96 is rigidly secured to the shaft 44 by means of a key 101 (Fig. 6) engaging a slot -102v (Fig. l) in the crank arm.

A bracket 103 (Fig. 1) is adjustably secured to the bearing casing 21 by means of bolts 104 passing through a slot 105 in an arm 106 extending `downwardly from and integral with the bracket 103. A blade or work holding member 107 is adjustably mounted in the bracket 103 by means of bolts 108 passing through elongated slots 109 in the member 107. The bracket 103 is of hollow construction and is connected with a pipe 110 so that the grinding fluid or coolant may run out over the member 107 and directly upon the work lw held between the regulating wheel 20, grinding whel 12, member 48 and the member 107.

In operation, the grinding wheel 12 is rotated at a suitable grinding speed (in the direction indicated by the arrow in Fig. 1) from any appropriate source of powemby means of the belt 13, and the regulatlng Wheel 204 is rotated slowly` (in the direction indicated by the arrow-in Fig. 1) b means of the motor 23 and parts associate therewith.

`The regulating wheel 20 and the member 107 are moved vertically to an appropriate osition for the particular size of work to4 e ground, by turning a hand wheel secured upon the shaft 38. The blade`or member 107 is then moved horizontally to a suitable position as determined by the size of the finished work and the bolts 108 are tightened.

The positioning member 48 ma beadjusted vertically between the regulatlng wheel '2O and the grinding wheel 12 by turning the pinion 31 engaging the rack 32 to raise or ower the slide 29 upon which the holder 43 is mounted. The member 48 may be adjusted horizontally relative to mounting 43 by means of the bolts 50. The stop screw 55 is then adjusted so as to limit as desired the distance which the positioning member V48 may travel toward a line connecting the centers of the grinding wheel and regulating the 'tact with the the wheel, that is, toward the left, as viwed in Figs. 1 and 5.

-With the movable work holding or work positioning-member 48 in its withdrawn posiv tion, that is, in aposition to the right of that shown in Fig.`1, a work piece w, which may be assumed to be for example a work piece having a shoulder or enlargement thereon such as a bolt, is inserted manually or otherwise between the grinding wheel 12, regulating wheel 20, member 107 and the member 48, the enlarged or headed portion thereof overhan 'n the side face of the wheels and the en e ges of the members 107 and 48. At this point it might further be noted' that with the member 48 withdrawn toward the right, the inserted work piece rests upon the upper surface of the regulating wheel 20 and against the member 48, being out of congrinding wheel 20 due to the fact that the adjacent operative surfaces ozt1 the two wheels arek progressively more distant from each other throughout a substantial range extending substanti-ally from the work engaging face of the member 107 towardthe right as viewed in Fig. 1. Themovable work holding member 48 during this period acts to prevent the work piece w Afrom rolling ot of the regulatingwheel, the parts being so arranged, as will be clear from both Figs. 1 and 5, that the workpiece lw is positioned to the right of a vertical plane passing through the axis of the regulating wheel 20. Also during this period the slowly moving surface of the regulating wheel 2O keeps the work piece w rotating so that during the subsequent operations to be more clearly described hereinafter the ultimate contact o f the work piece with the grinding wheel finds the work piece in an already rotating condition.

By thereupon moving the lever 85 to the left and into substantially the position shown in Fig. l or 'in a clockwise direction as viewed in Fig. 2, the shaft 44 is rotated to move the eccentric portions 46 thereon within their bearings 47 and move the mounting 43 together with the positioning member 48 forward (to th'e left as viewed in Figs. 1 and 5) towards grinding throat. In this manner the positioning member 48 moved with the work lw to move the latter laterally into contact with the grinding wheel and then feed or continue to move the work forward -into the narrower portions of grindin throat and thus cause it to be progressive y reduced in size. This member 48 maintains the. work in operative contact with the wheels until it has been brought tothe desired predetermined size as limited by the setting of the stop screw 55. Also the relatively fixed blade or work holdin member 107 ma be suitably set or adjuste to'such a position that the a work piece w will come in contact with it as soon as the work piece hasbeen reduced to the desired size, thus further preventing further movement of the workpiece toward still narrower portions of the grinding throat. Y

wheels'where the latter are of the peripheral type and where one wheel is arranged above the two wheels.

the other, thereby insuring a movement of Ithe work piece in a direction transversely of its axis and between progressively narrower portions of the grinding throat formed by It is also to be notedthat during these actions the regulating wheel continues to control the rotation of the work piece w while the grinding wheel 12 performs a grinding operation thereon.

When theV grinding has been finished, the lever 85 is moved toward the right as viewed in Fig. 1 (or in counterclockwise direction as viewed in Fig. 2) as quickly as is desired until the pin 9 3 is brought into engagement with the rear end of the slot 92 (Fig. 2). This movement of the lever 85 acts through the linkages 94 96 to rotate the eccentric shaft 44 in reverse direction and thus to commence the movement of the positioning member 48 .in a direction toward the right as viewed in Figs. 1 and 5, thus permitting the work piece fw, while still beingV rotated by the regulating vwheel 20, to roll toward the right and into a wider portion of the grinding throat. -As the movement of the lever 85 is continued toward the right, the arm 88 is turned about its pivot bolt 89 to pull upon the rope 77 and thereby move the piston 69 against the action of the spring 70 to force the pusher rod 73 axially between the wheels to discharge the ground work w. The lever 85 is then moved towards the left (as viewed in Fig. 1) until the .pin 93 engages the forward end of the.

slot 92 thereby permitting the'spring 70 to return 'the pusher rod 73 to the position shown in Fig. 2. Vith the lever 85 in this position the positioning member '48 stands in its rearward position a sutiicient distance from the grinding throat to permit replacement of the work. A new work piece is then inserted between the wheels and in contact with the positioning member 48, and the movement of the lever 85 is continued toward the left at a rate governed by the skill and experience of the operator in the particular type ot' grinding operation being performed until the new work piece is brought to the desired predetermined size.

ln Fig. 7 of the drawings, I have indicated in a diagrammatic manner the application of the invention to a type of centerless grinding machine in which the centers of the grinding wheel and the work regulating wheel are positioned in substantially the same horizontal plane. As illustrated, the grinding wheel 120 is mounted to be rotated rapidly in the direction .indicated by the arrow by suitable mechanism, and the work regulating wheel 121 is similarly mounted for rotation slowl in the direction indicated by the arrow.

work piece is positioned between the wheels 4means of a key 130 therein adapted to engage a slot 131 in the crank arm. Movement of the positioning member 122 upward may be limited by a stop screw 132 adjustably mounted in a lug 133 in the frame 128 to engage the crank arm 129. It will be now apparent in view of the foregoing to those skilled in the art that the work may be fed into the grind- `ingthroat between the wheels so that it may be ground to a predetermined desired size by moving the crank arm 129 to the right, and the positioning member 122 may be withdrawn quickly to permit discharge of ground work by moving the crank arm to the left.

Also, as will be seen in Fig. 7, I prefer in this vform of apparatus to relate the parts so that upon movement of the work holding member 122 upwardly the work piece supported there- .bywill be moved toward the line connecting the centers of the two wheels and hence into contact with the less and less distant portions of the two wheels; this relation of the parts is clearly indicated in Fig.'7. Also, it will be seen that the work piece carried by the member 122 is moved in a direction opposed to the downward thrust of the grinding wheel thereon andthat the extent of the grinding operation performed on the work while the latter is being rotated by the regulating wheel 121 may be predetermined by adjustment of the stop screw 132 which limits the movement of the crank arm 129.

It will therefore be seen that in accordance with certain features of the invention the work may be moved laterally into the narrowing grinding throat between the wheels in opposition to the thrust of the grinding wheel upon the work at a controllable rate, vthereby a machine adapted for economically and ediciently grinding successive work pieces havin shoulders or enlargements thereon upon an e cient production basis to a predetermined size. It will be understood that I prefer to achieve the narrowing grinding throat for coaction with the work moving devices above described by utilizing peripherally opposed peripheral wheels but that I may achieve many of the features of this invention'with other shapes of Wheels.

invention an apparatus in which the several objects hereinbefore noted as well as many advantages are successfully achieved and that the apparatus is well adapted to meet the varying conditions of hard practical use.

As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, what claim as new and desire to secure by Letters Patent is:

1. A centerless grinding machine comprising a rapidly rotated grinding wheel, a slowly rotated work regulating wheel, a positioning member for maintalning work of round section in operative contact with the wheels, and Y means for moving said member in a direction substantially transversely of the axis of the work piece and in opposition to the thrust of the grinding wheel to cause the work to be b ground to a predetermined size while being rotated by regulating wheel and thereafter withdraw it to permit removal and replace- .ing a rapidly rotated grinding wheel, a s

ment of the finished work.

2. .A` centerless grindin machine comprising a rapidly'rotated grin ing wheel, a slowly rotated work regulating wheel, a work positioning member, means for adjusting said member laterally and vertically to accommodate different sizes of work, and a mechanism for moving said member to force the work into the grinding throat and cause it to be ground to a predetermined size and thereafter permit discharge of the work.

3. A centerless grinding machine comprising a rapidly rotated grinding wheel, a slowly rotated work regulating wheel, a work positioning member arranged to move work of round section into the grinding throat in a direction substantially transversely to the' axis of the work and'in opposition to the thrust of the grinding wheel so that the work may be ground to a desired predetermined size and thereafter to withdraw,-. and means for discharging the ground w 'iik axially when said member is withdrawnlz g.

4. A centerless grinding machine compris ow 1y rotated work regulating'wheel, a movable It will furthermore* be seen that there has been provided in this work-positioning member, a mechanism for movin said member to force the work into the grinding throat in opposition to the thrust of the grinding wheel until ground to a predetermined s ize and thereafter withdraw, a reciprocable plunger; Ifor discharging the ground work when said member is withdrawn, and means for controlling the movement of said mechanism and said plunger and for' causing said mechanism and said plunger 4to operate in proper sequence. y

5. In grinding apparatus, in combination, a grinding throat in which work'of round s ection is received for simultaneous "grindlng and rotation, said grinding throat including a grinding wheel-rotatable at relatively high speed, a regulating wheel rotatable at relatively low speed, vsaid wheels being adapted to present adjacent operative surfaces travcling in opposite directions, said wheels being opposed to one another and having their operative surfaces substantially approaching each other so as to form a grinding throat of varying\width, and a movable member for holding work in operative relation to said two wheels, and means for moving said workhol'cling-member in a direction substantially transverselvof the axis of the work piece held hereby and with the work piece interposed between it and the narrower portion of said grinding throat so as to carry the, work toward the narrower portion of said grinding throat, thereby teef-feet progressive reduction in diameter of thewvork, and means for limiting the movement of said work-holding memer. L

6. In grinding apparatus, in combination, a grinding wheel rotatable at a grinding speed, a' slowly rotated work-regulating wheel, `a member for'holdingw'ork in operative relation to said two wheels, means for moving said member. with a piece of work to be ground in a direction opposed to that in which the thrust of the grinding wheel is exerted, thereby to cause the l`,work to be ground tqa predetermined size',and for thereaftenwithdrawing said memberto permit removal of thegroundrwork, a-plunger movable in a direction to eiect the work piece fromthe grinding throat formedby said two wheels and mechanism for operating said plunger .two wheels, and in a direction to move and 'hold the work piece against the thrust of the grinding wheel while being rotated by said regulating wheel. Y 8. In grinding aapparatus, in combmation, a grinding throatin'which work of round section is received for simultaneous grlnding l and rotation, said grinding throat including' a. grinding wheel rotatable at relatively hlgh speed, a regulating wheel rotatable at relatively low speed, said wheels being adapted to present adjacent operative surfaces traveling in opposite directions and having their operativesurfaces substantially approachlng so as to form a grinding throat of varying width, means fon moving a Work plece substantially transversely of its axis mto said grinding -`throat, means for moving a'work piece out of said grinding throat, a lever,

. means forming a direct connection between said lever and one of said means for actuating the latter by said lever, and means forming a lost motion connection between said lever and the other of said means for actuating the latter by said lever. Signed at Detroit, Michigan, this 27 th day of March, 1926.

' lFRED M. KERN.

DISCLAIMER 1,737,852.Ifred M. Kern, Detroit, Mich. CENTERLESS GRINDlNc MAUHINE. Patent dated December 3, 1929. Disclaimer filed April 3, 1931, by the `assignee,.Uz'rz'fnratz' Grinders I aaorporated.v

Hereby enters this disclaimer tothe subject matter of claims l, 5, and 7 in the said specification, which claims read as follows 1. A centerless grinding machine comprising a rapidly rotated grinding wheel, a slowly rotated work regulating wheel, a positioning member for-maintaining work of round section inoperative contact with the wheels, and means for moving said member in a direction substantially transversely of the aXis of the owork piece and in opposition to the thrust of the grinding wheel to cause the work to be ground to a predetermined size while being rotated by said regulating Wheel and thereafter withdraw it to permit. removal and replacement ofthe finished work.

5.`In grindingv apparatus, in combination, al grinding throat in which work of round section is received for simultaneousgrinding andi rotation, said grinding `throat including a grinding Wheel rotatable at relatively high speed, a regulating wheel rotatable at relatively low speed,.said Wheelsbeing adapted to present adjacent operative surfaces traveling 1n opposite directions, said wheels beingopposed to one another and having their operative surfaces" substantially approaching eac-h other so as to `form a grinding throat-of varying width, and a movable member for holding work in operative relation tosaid two wheels, and means for moving said work-holding member .in a direction substantially transversely of the axis of the work piece held thereby and with the work piece interposed between it and the narrower portion of said grinding throat so` as to carry the worktoward the narrower portion/of Ysaid. grinding-throat, thereby to effect progressive reduction in diameter ofthe work, and means for limiting the movement of said work-holding member.

7. 'In grinding apparatus, in combination, a rapidlyl rotated grinding Wheel, a slowly rotated work-regulating Wheel, fi-movable member for holding work of roundsection between said wheels, and means 'for moving said member with a work piece thereon in an direction substantially transversely of the axis of the work, thereby to carry 'said work piece into the grinding throat formed by said two wheels, and ina direction to move and hold the work piece against the thrust of the grinding' wheel while being rotated by said regulating'wheel.

[Oficial Gazette April 21, 1.931

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