US1881870A - Grinding machine - Google Patents

Description

Oct. 1l, 1932. L, NENNlNGER 1,881,870

GRINDING MACHINE Filed Jan. 25, 1932 5 Sheets-Sheet l Oct. l1, 1932. F. NENNINGER GRINDING MACHINE Filed Jan. 25, 1932 5 Sheets-Sheet 2 Oct. 11, 1932. 1 F. NENNINGER GRINDING MACHINE Filed Jan. 25, 1932 5 Sheebsfsheet 5 N%\ 1 N NN MNMII Oct. 11, 1932.

L. F. NENNINGER GRINDING MACHINE 5Sheets-Sheet 4 Filed Jan. 25, 1932 griff/75 Oct. 11, 1932. F. NENNINGER GRINDING MACHINE Filed Jan. 25. 1932 5 Sheets-Sheet 5 v Mmm;

Patented Oct. 1l, 1932 y n "1,381,87a A,

f UNITED STATES A. PMlf-:Nr- OFFICE LESTER F. mman, oir cI'NcnrNATI, omo, ASSIGNOR, BY mim maremma, 'ro' THE HEALD MACHINE conPANYfor woncns'rna, nassacnusar'rs, a confesar TION 0F MASSACHUSETTS emma automa Application med January 25, 1832. Serial No. 588,827.

This invention relates to improvements in grinding machines and especially to improvements in a mechanism for maintaining sizes of work pieces being ground.

Attempts have been made in the past to automatically control the size of work pieces while bein operated on or ground. Difficulty has en experienced in the accurate proper performance of these mechanisms especially when employed with internal grinding machines and when attempting to control the-size of the hole or bore being ground. This was. caused by variations inthe outside diameter of the work which was the determinator for the hole and its size. By the mechanism of this invention these difficulties have been overcome and the size of the hole or bore maintained regardless of the size of the outside circumference.

It is, therefore, one of the principal objects of the present invention to provide a mechanisrn which will control the size of thebore or hole in successive work pieces regardless of the sizes of the outside diameter.

Another object ofthe invention is the provision of a compensating mechanism operating and controlling the sizing mechanism for positioning same in accordance with the finished outside size of the work.

A further obj ect of the invention is the provision of a mechanism as above set forth operating in an automatic manner in timed sequence with the automatic portions of the balance of the machine.

, Other objects and advantages of the present invention should be readily apparent by reference to the following specification considered in conjunction with the accompanying drawings forming a part thereof and it is to be unders od that any modifications may be made the exact structural details there shown and described within the scope of the appen ded` claims without departing from or exceeding the spirit of the invention. In the drawings: Figure 1 is a front elevation of a grinding machine embodying the improvements of this invention.

Figure 2 is a topI plan view of the machine shown in Figure 1.

Figure 3 is a sectional view 'taken on line 3--3 of Figure 2.

Figure 4 is a fragmentary sectional view i' stantially from line 8-8 of Figure'l.

Figure 9 is a sectional view taken in a plane parallel with but ahead of the structure shown in Figure 8.

Figure 10 is a sectional view taken on line 10-10 of Figure 8.

Figure 11 is a diagrammatic view illustratl ing the hydraulic and electrical circuits involved in the machine with which this invention isemployed.

Throughout the several views, similar reference characters are employed to denote the same or similar parts.-

This invention is particularly useful with automatic machines such as internal grinding machines. The invention has therefore been illustrated in conjunction with an internal grinding machine which is operated in accordance with centerless grinder prin-l ci les. Accordingly, the machine comprises a d 15 having formed on its upper surface spaced ways 16 and 17 respectively supporting a wheel head indicated generally bythe referenceJ character 18 and a work head likewise indicated generally by the reference character 19. The wheel head and Work head are each ada ted to be shifted relative to the ways 16 an 17 for operatively associating the work and grinding wheel and for breaking up grinding lines and the like on the work and for producing-the desired finishthereon.

f The wheel head 18 comprises a slide20 which directly engages the ways 16 and sup'- carrying a small 'ameter or internal grindports thereon a prime mover or electric moing wheel 2,4. The motor 21 is adapted to rotate the grinding wheel 24 at the usual high grinding rate of speed for effecting the stock removal from the work supported bythe work head. The slide 20 is secured in any desirable manner to the forward end ofua` vy y the friction drlve or regulating wheel 44 and piston rod 25, see Figure 11,v which extends from a piston 26 inclosed in a cyllnder 27 supported by the bed interiorly thereof. A spool valve 28 mounted in a valve casing 29 is employed for directing the hydraulic pressure to opposite ends of the cylinder 27. This valve 28 has extending from it a suitable Stem or connecting member for attaching the valve to the control handle 30 oscillatably mounted at 31 on the forward face of the bed 15. A valve 28 is adapted to be automatically reversed at each end of the stroke of the slide 20 for which purpose it is provided on its forward face with a T-slot 32 whereby do s 33 and 34 are adjustably secured to the slidge. The operating portions of the dogs 33 and- 34 have disposed between them the free end of the lever 30 and are adapted to engage the said lever for shifting same for correspondingly shifting the valve 28.

The work head 19 includes a main slide 35 which directlyengages with the table guide- Ways 17 and has projecting from itsupper surface a dove-tailed ide or tongue 36 received in acorrespondmgly shaped guideway 37 formed in the lower surface of a cross sli de 38. This slide 38 in turn supports an oscillatable or rotary slide 39 on which the work is mounted as will later appear. The slide 39 has rising from it a housing 40 which supports on the upper surface thereof a rime mover or motor 41 geared through suitable transmission inclosed within the guard 42 and housing with as indle 43, see Figure 3, rotatably journale'd ln'suitable bearings provided by the housing 40. The spindle 43- has secured to it for movement therewith the friction drive or work rotation control wheel 44 which is employed for effecting the rotation of the work while being operated upon.

Mounted on the swivel slide 39 is a supplementary slide 45. This slide 45 isI provided nea-r its inner end with ears or 1u s 46 forming bearings for a shaft 47 on which is oscillatably journaled a cradle or swinging bracket 48. The bracket 48 `terminates in a ball socket 49receiv'ing the ball end 50 of an arm or bracket 51.'v A cap 52 is mounted on the cradle 48 and clamps the ball 50 in. any of its adjusted positions." The arm orbracket 51 has journaled'in its'free end a shaft'or spindle 53 to which is secured a disk or roller 54 which in: actual-practice is opped to the regulating or friction drive wheel 44 land bee tween the proximate points Aof said disk or pressureroll 54 and l regulating wheel 44 is formedv the grinding throat. The disk or roller 54'is further adjustedthrough its ball. and socket connection .to dispose its axisv 4be, described;

aty an 'angle tothe axis ofv thev friction drive or regulating 'wheel thereby exerting a feed com onent or thrust on the work in a rear-` wa direction for a purpose that will later Mounted on the swivel slide 39 in between thel disk or pressure-roller 54 is an adjustable bracket, whichpsee Figure 3,.carries thel work rest blade 56. this blade 56 is provided with an inclined upper surface 57 which inclines in a directioutoward the o erative'face of the'friction drive or regulating wheelf44 and forms therewith a work receiving trough. The bracket has rising therefrom on the rear surface of the work a plate 58 against which the work is held by the said component or'thrust exerted thereon by the pressure roll or disk54. The bracket 55 has mounted in it near its outer end a spring pressed plunger 59 abutting on its upper end with the cradle or bracket 48 and yieldingly actuating the ,cradle in a'clockwise direction about its pivot shaft 47 into engagement with the work piece GOjInOunted on the'` work rest blade 56 and holdin -same in operative engagement with.l

the inc ined face 57 ofthe bladeA and the operative surface of the' wheel 44. In other words, a yielding pressure is at all times maintained `on the work while being ground to prevent any tilting or lateral movement of the work and insuring same rotating about an thereofv s At the conclusion of the grinding operation the cradle or bracket 48`is oscillated in a counterclockwise direction about the shaft 47 thereby withdrawing the pressure roll or disk-'54 from the work whereupon the work `is automatically withdrawn from the grinding throat and anew work-piece substituted therefor." To this end the cradle 48 has projecting from it a, roller 61 adapted to be engaged by a'cam 62 having the cam portion 63 ormed thereon. The cam 62 is secured to a shaft 64 rotatably mounted in a housing 65 integral 'with or secured to the supplemental. slide 45. The shaft 64 has secured to it within the housin 65 av gear or pinion 66 meshing with the `mutilated gear 67.' This gear 67 is loosely vjournaled on a pin or shaft 68 carried by the housing 65 and is further provided with a small mutilated gear 69 meshing with a rack v70. The large mutilated gear 67 also meshes with a gear or pinion 71 secured to a shaft 72 journaled in the housing 65 and having secured to it at a point outside the "housing an ejector arm 73 adapted to engage the work at the conclusion of the grinding o peration and withdraw it from the machine.

The mutilated gear 67-69 is operated by the rack which is secured to or formed integral with a piston 74 inelosed within a cylinder 75 formed in the supplemental bracket 45.

'The cylinder 75 is closed at one end by means *axis determined by the finished outer surface of a cap or head 76 carrying an adjustable abutment screw 77. The other end of the cylinder 75 is also closed by a cap or head 78 in which is adjustably mounted a plug 79 having the shoulder 80 formed thereon and forming an abutment for the piston 74 to limit its' movement to the right, as seen in Fi re 3. The plug 79 has pro ecting from it a clrcular tubular sleeve 81 w ich 1s encircled by the adjacent end of the piston 74. The piston 74 is further formed interiorly thereof and at the end of the tubular sleeve with a chamber 82. The plug 79 is provided through the sleeve 81 with crossports 83 and with additional cross ports 84 ata' point within t-he cap or head 78. The head/78 is furtherV provided with a port 85 communicatin with the ports 84. The ort 85 in the head 8 is controlled by an adjustable choke or needle valve 86. A main port 87 is formed in the slide 45 which terminates in the end of the cylinder ad'acent the ca or head 78. The slide 45 is further provi ed with a main port 88 which terminates in the cylinder at the end adjacent the cap or head 76.

After the work piece has been reduced to the desired size, the hydraulic pressure is introduced into the cylinder at the end carryingthe head7 8 for forcing the piston 74 therein to the right, as seen in Figure 3. This movement of the piston 74 oscillates the mutilated gear 67--69 in a counterclockwise direction about the shaft 68 thereby rotating the pinions 66 and 71 in a clockwise direction, as viewed in Figure 3. The movement of these pinions first causes the arm 73 to descend into substantial engagement with the work whereupon the pressure roll or disk 54 is withdrawn from the work through the inter-engagement of the cam 62 and roller 61. At this point the hydraulic pressure is reversed and is directed into the cylinder through the port 88 thereby shifting the piston to the left, as seen in Fi ure 3, and car ing the work out of the grin ing throat an discharging it into thechute or trough 89. `The flow of the hydraulic medium is controlled by a suitable valve which will be described in detail later.

It is desired that the ejector arm approach the work at a rapid rate and that it carry the work from the machine and discharge it into the chute 89 at a slower rate. For this reason the pressure has an unobstructed flow through the port 87 into the cylinder 75 and an unobstructed iiow from the other end of the cylinder through the port 88, but when the piston is actuated in the reverse direction, the discharge of the medium into the port 87 is restricted for thereby slowing up the movement of the piston 74 tothe left. This is accomplished by trapping some of the hydraulic medium within the recess or chamber 82 and forcing same out through the hollow interior of the sleeve 81, through the cross ports 84, restricted port 85 into 74 is movin to the left, as in Figure 3.

For effecting the automatic reverse of the valve controlling the movement of the piston l74 and the subsequent movement of the maton 74 and the longitudinal movement of the vthe main conduit 87 when the said piston i main wheel head slide 35 as will be describedy in detail later.

Mounted on the cross slide 38 adjacent the friction drive 'or regulating wheel 44 is al slide-94 having rising therefrom a bracket or support 95 and terminating in a ledge or shelf 96. An L-shaped bracket 97 having an elongated perforation 98 is mounted on the shelf 96 and has passing therethrough a bolt or the like 99 whereby the bracket 97 is adjustably secured to the'shelf 96. The upper end of the bracket 97 has projecting through it a screw 100 having the head 101 thereof received'j in a T-slot 102- formed in channel member 103 which is carried by the sizing device housing 104. This housing 104 has inclosed therein a lever 105 secured to a shaft 106 oscillatably mounted in the lower end ofthe housing 104. Secured to the shaft 106 and depending exteriorly of the housing 104 is a linger 107 carrying a diamond sizing point 108 and adapted to be engaged by the operative face of the grinding wheel 24 when the work is reduced to the desired size. Upon reduction of the work to the desired size, the lever 105 is oscillated in a counterclockwise direction for engaging an electrical contact 109 carried thereby with a second electrical contact 110 carried bythe housing 104 and completing any electrical circuit for effecting part of the automatic cycle of the machine as will later a pear. The arm 105 is held in its circuit making position by -a magnetic coil or solenoid 111 which is energized upon completion of the electrical circuit through the contacts 109 and 110.

' The cross slide 38 is actuated by hydraulic i pressure acting on one end of a piston 112 which has projecting from it, intermediate its ends, a pin 113 received in a slide block 114 mounted between the arms of a fork 115 on the lower end of a lever 116. The lever 116 is keyed or otherwise secured to a shaft 117 supported by a bracket 118 secured to the under surface of the cross slide 38. The bracket 118 is also formed with a cylinder 119 in which is mounted the piston 112. Keyed or otherwise secured to the shaft 117 for oscillatory movement therewith as is imparted thereto by piston 112, is a cam 120 having its cam face 121 adapted to engage with aproller 122 carried by a nut 123 threaded L... .Ls-d

longitudinal movementv in the `crosss1ide38 y 12'4 4ie'. leeked egeinet independent` means of collars 125 anda shoulder 126l formed-thereon. Fromj/this it will be seen that as .the arm 116:; oscillated, through the shafti117, it effects corresponding oscillation of the cam 120 thereby moving the vnut axially of itself, which carries with itl the screw 124 and slide 38. This movement of the cross lslide 38 and parts carried thereby effects the feed between the grinding'wheel and Work to reduce said work to the desired s1ze. i v

As is well lmown, wheels are sub- 'ect to considerable wear an must be periodically trued or resurfaced to maintain the proper grinding face which effects the size thereof which must be compensated for if successivel work pieces are reduced to the desired size especially since the cam 120 has but a limited throw. For this reason the piston 112 is provided on the surface opposite to that shown in Figure 9 with a rack adapted to mesh with pinion 127 of a compound gear 128 freely rotatabl mounted on.a stud 129 carried by the bracket 118. The second gear 130 of the compound gear 128 meshes with a pinion 131 keyed or otherwise secured to a vertical shaft 132 which has on itsv upper end a bevel gear 133. This gear meshes with a complementary bevel ear 134 splined on a transverse shaft 135 w ich passes throu h the hollow interior of the screw 124. T e outer end of the shaft 135 has keyed to it a pawl carrier 136 having oscillatably mounted thereon at 137 pawls 138 and 139. The pawls 138 and 139 are respectively ada ted to be engaged with fine and coarse ratc ets 140 and 141 keyed or otherwise secured to the extending portion of the screw 124. The pawls are spring actuated as by means of springs v142 to engage same with the teeth of the ratchets 140 and 141. The awls have projecting from them a tail .143 or engagement with lock-out screws 144.

The operation of these parts is as follows: Dependmg on whether the grinding machine is performing a roughing or a finishing cut one or the other of the pawls 138 or 139 will be locked out by means of the screws 144. In other words, if a roughing operation is being performed then the coarse toothed ratchet will be employed and if a finishing operation, the fine toothed ratchet will be used. The pawl carrier is oscillated in opposite directions each time the piston 112 makes a forward and a reverse stroke or in unison with the oscillations of the feedin cam 120. The parts are so arranged that uring the feeding movemeit between the work and grinding wheel, the pawl is riding idly over the ratchet teeth reparatory to feeding or actuating the said ratchet in a feeding direction during the retracting stroke of the work and wheel. In other words, if the wheel has been worn or trimmed away to a point where `a considerable throw of the cam .is necessary, to v cause engagement between the -wheel and sizing` diamond, the pawl will f "drop behind a tooth on thev ratchet and advance it to compensate for the wheel wear.

vIn thepast while the sizing device was ad- "justable, for various sizes of work pieces through the bolts 99 and 100, it wasA not -mounted on a slide such as 94. After the sizing device was so adjusted, it was secured in place andbore a definite relation to the remaining parts of the machine. If work ieces were not held to a deniteoutside iameter, the holes or bores in said subsequent work pieces varied in accordance with the outside diameter variation because the centers of the bores being ground were variably positioned relative to the sizing point or diamond due` to the definite relationship existing between the sizing point or diamond Vand the operative point of c'ontact of the regulating or friction drive wheel with the outside diameter of the work. p

Therefore, if the work piece were oversize by even one or two thousandths'of an inch, the center of the work was shifted from the sizing point or diamond one-half that amount and when the automatic feed was thrown in, it continued until the grinding wheel engaged the sizing diamond or point, which, however, did not occur until the work was reduced beyond the desiredl point an amount equal to the oversize of the outside diameter of the work. On the other hand, if the work were undersize, then the center thereof was shifted toward the sizing or diamond point and a lesser amount of grinding resulted than was desired, causing the work piece to have a bore or hole under the desired size and requirin an additional grinding operation to rectiy the error. By this invention, the variations in the outside diameter of the work are compensated for so that successive work pieces are reduced to the exact desired size regardless of the circumference size of successive work pieces.

Accordingly the sizing mechanism, as above described, is mounted on a slide such as 94 and has projecting therefroma rod 145 which passes through a bore 146 formed in the bracket or slide 45. The rod 145 has near its forward end an enlarged bearing 147 which provides a shoulder 148 forming one abutment for a spring 149 encircling the rod 145 and contained within the bore 146. The rear end of this bore 146 is reduced to provide a shoulder 150 which forms the remaining abutment for the spring 149 and due to this construction, the slide 94 is continuously spring 149 in contact with the compensating 1::

1,es1,avo

' cam 152. This cam 152 is keyed or otherv is a mutilated gear or pinion 158 having its are of di teeth 159 in operative engagement with a rack 160 formed inte ral vwith or secured toa iston 161. The piston 161 is contained wit in vertically dis osed cylinder 162 closed on one end by a hea 163 and on the other end by a head 164 formed integral with a bracket 165. The bracket 165 is secured as by bolts or the like 166 to the cross slide 38. v

The reective cam surfaces 154 and 155 rise relative to one another or in other words,k the rise of the cam surface 155 is such as re ects that of the cam surface 154 that the rol er 151 is actuated through one half of the distance that the position of the pressure roller 54 varies inits movements between successive work 'eces. The cam 152 is further provided wit a depression or recess 167 at the end of the cam rise 155 into which the roller 156 drops in order to withdraw the pressure roller or disk 54 from the work.

The cylinder 162 is coupled with the cylini der so that both of the contained pistons are. actuated at the same time, but due to the f clearance and relationship between the cradle roller 61 and its operating cam 62, the cam 152 is actuated before thev cradle is oscillated, thereby bringing the recess 167 of the cam 152 in alignment with the roller 156 so that upon engagement betweenl the cam face 63 of the cam 62 with the rol1er61 no interference is set up against the oscillation of the said cradle.

In the operation of the compensating cam, a work piece is introduced into the machine and the cradle released by disengaging the cam face 63 and roller 61 whereupon the spring pressed plunger 59 oscillates the said cradle to cause the pressure roller or disk 54 to engage the work and hold the same in contact with the friction drive wheel and work rest blade. The compensating cam 152 is now rotated which has, as above noted, the roller 156 engaging the cam face 155 and the roller 151 engaging the face 154. The oscillation of the cradle about its pivot is controlled by the outside diameterof the work, that is, if successive work pieces vary in size the oscillation of cradle wlll be more or less and will vary by an amount equal to the difference in said successive work pieces. Now upon rotation of the cam 152 the cam face 155 will contact with the roller 156 at a point which represents the particular size of the work about to be operated upon and as soon erent pitch or of a di'erent cam t verein and stopping furt as" this point is reacted further' 'rotation of the cam will be stopped. During the rota-.I

tion'of this cam its cam face 154.was, throu h the roller 151, shitin therod 145 rear'wa ly and thereby adjusting the slide 94 and 'sizl ing mechanism relative to the inding throat to a point representative of t e desired size of the hole to be eground in the particular piece being operat mechanism operates on but oneside vof the work, or on the radius of the hole, it 'need only move vone-half of the distance that the presupon. Since the sizing 'l sure roll moves therefore, the difference be- 4 tween the cam aces 154 and 155. From the foregoin it is believed, that itwill be seen there has een provided a mechanism for pro-A ducing work pieces havin the bore therein all'to the same size regar less of the condi tion' of the outside of the work piece when mounted in the machine. v

The automatic machine diagrammatically shown in Figure 11, operates as follows. The switch contacts 109 and 110 of the sizing mechanism are shown diagrammatically yin this figure at 168, which are closed when .the work is to the desired size for completing an electrical circuit through the lines 169 and 170 which includes the solenoid 171. The solenoid 171 shifts a valve 172, which directs the h draulic pressure to one side ofthe c lin er 119 for retractin the piston 112 Eer feed between the grinding wheell and work. As diagrammatically illustrated in this gure, a tank or sump 176 is provided containingan hydraulic medium, referably oil, which is drawn therefrom t rough pipe or conduit 177 by a ump 178 and forced into the pressure line 1 9 under working pressure.. A branch conduit 180 from the line' 179 carries' the medium to the valve 172 where it is directed through conduit 181 to the end of the cylinder 119. The'hydraulic medium ahead of the'piston 112 is discharged through conduit 185 and 186 is completed or energizing the solenoid 187 which likewise effects the shifting of a valve 188 for directing the hydraulic medium from theconduit 179 through the branch conduit or line 189 to oneend of the work head` traversing cylinder 190. i This cylinder 190 contains a plston 191 connected by thepiston rod 192 to the work lHead slide for effecting its movement towarf and from -the grinding wheel for operatively associating and disassociating said wheel and work. The hydraulic medium ahead of the piston 191 is conveyed by conduit 193 to the valve 188 where` it is ldirected to the conduit 194 terminating in the valve casing 195 which contains the valve 196. ThisV valve 196 connects the conduit 194 with either the restricted branch discharge conduit 197 or, and as illustrated, with the ranch return conduit 198 which terminates in valve chamber 199. The medium asses from the chamber 199 through a con uit 200 to the branch and main return conduits 183 and 184.

When the slide reaches its rearmost position it closes a switch 201 for completing an electrical circuit through wires or leads 202 and 203 which include a solenoid 204. The solenoid 204 eifects the shifting of a valve 205 which connects the h draulic medium in the pressure line 179 wit either of conduits 87 or 88 which, as above noted, terminate at opposite ends of the cylinder 75. Branch conduits 206 and 207 respectively extending from the conduits 87 and 88 terminate at correspondingly opposite ends of the cylin.

der 162 for actuating the piston 161 therein.

As noted above, these pistons respectively shift the ejector arm and cradle andv the compensating cam 152. As was above noted, when the piston 74 reaches the end of its stroke in one direction for eiectin engagement between the ejector arm an finished work and the retraction of the pressure roller from the work, it through the cam 90 closes one of the switches 92, indicated in Figure 11 by the numeral 92A. The closing of this switch completes an electrical circuit through the lines 208 and 209 which include the solenoid 210. Ener 'zation of the solenoid 210 reversely shifts t e valve 205 which immediately connects the hydraulic medium with the other ends of the cylinders 75 and 162, causing a retraction of the pistons 74 and 161 for raising the ejector arm 73, permitting a re-engagement between the pressure roller 54 and work and a setting of the sizing mechanism in accordance with the particular diameter of the work now in the grinding throat. When the piston 7 4`reaches its limit of travel it closes the second of the switches 92 through the cam'91, indicated dia rammatically in Figure 11 by the numera 92B, which then completes an electrical circuit including the wires 208 and 211 which have in series therewith the solenoid 212. This solenoid reversely shifts valve 188 for connecting the hydraulic medium with the forward end of the piston 191 causin the work head to travel toward the wheel ead for operatively associating the work and wheel. When the work head reaches its innermost position, it closes an electrical switch 213 completing an electrical circuit through the wires 214 and 215 thereby energizing the solenoid 216 and reversely shifting the valve 172. This valve 172 then eiects or initiates the movement of the piston 112 for feeding the work and wheel relative to one another and effecting a stock removal from the work. As

has been noted above, this feed continues;

until the grinding wheel 24 en ges the sizin vdiamond ci' point 108 w ereu n the switch 168 is closed for initiating t e" automatic c cle of the machine as above outlined.

As urtherl illustrated, diagrammatically in Figure 11 and structurally in Figure 3, to retrue or redress the active face of fthe grinding wheel,gther'e is provided a `lpiston cylinder 217 vwhich is rforme'd on the Asame casting as containsthe Avalve chamber 199. Inclosed within the cylinder217 isfa piston 218 having projecting therefrom a rod 219 bearing a post 220 in which is mounted the truing tool or diamond 221'. ,Connected with the piston 218 is avalve member 222 movable with the piston 218through the valve chamber 199 for controlling the flow of the hydraulic medium through thev lsaid. chamber from the conduit 198 to the conduit 200.

The iston 218 is hydraulically shifted by the hy raulic. medium under pressurev passing through branch conduit 223 to the valve 196 where it is connected with either of conduits 224 and 225'respectively Vterminating' at opposite ends` of vthe cylinder 217. The valve 196 is adapted to be periodically shifted throu li'4 a lever 226 and solenoids '227 and 228. he former is included in the electrical circuit 229 and 230 which is interruptable by a switch 231 mounted on the rear surface 0f the bed- 15. vThe switch is closed by a dog 232 secured to the' rear surface of the Vwork head slide .35. Substantially at the same time of closing of the switch 231 by the work head slide a second switch, 233, also mounted on the rear surface of the bed 15, is closed by'meansof a dog 234 carried by the wheel head slidewhich com letes an electrical circuit 235 and 236. T -e closing of this circuit energizes a solenoid 237 shiftin a stop valve 238 for stopping thewheel hea After the wheel has been retrued a second dogk 239 carried by' the work headslide 35 closes a switch 240 completing an electrical circuit 241 and 242 for ener 'zing solenoids 228 and 243 for reversely shi ting the valves 196and 238 for returning thegparts to their normal 'opi erating position.

From the foregoing, it will be noted that scribed lthe combination of a bed, a work support on the'bed, a `grinding wheel on the bed, meansffr effecting a relative `feed be- *l tweenthe grinding wheeland work, a sizing device for vengagement with the wheel for automatically stoppinglthe relative feed between the work and wheel when. the work is i ground.

'20 sive work pleces are reduced to theA desired size, 'and means for automatically adjusting the position of the sizing device relative to the work and wheel in accordance with the size of the work being 2. In an. internal rindin machine for grinding the hole or re o a work piece concentric with the outside finished diameter thereof, the combination of means for supporting the w'ork on said outside finished periphera surface, a fgrinding wheel, a feedmg mechanism for e ecting a relative feed between the vwork and wheel, means operable when the work is tothe desired size for stop-l 4Ill! ping further feed between the work and wheel, and means for adjusting the position of the sizing devices in accordance with the outside diameter of the particular piece of work being operated upon whereupon succesproduced having the same size bore.

3. In an internal grinding machine of the class described the combination of a work support peripherally supporting the work on its exterior diameter, agrinding wheel for grinding a bore in the work concentric with v the `said exterior diameter, a feeding mechanism for effecting relative movement between the grindin wheel and work, means for holding the wor on its support and for contacting with said work, a sizing device for en gagement with the grinding wheel to sus nd urther feed between the work and w eel, and means operated through the movement of the work contacting member for adjusting the position of the sizingdevice relative to the grinding wheel.

.4.' In an internal grinder of the class described the combination of a bed, a work head 4o mounted thereon for movement relative thereto, a wheel head mounted on the bed port on the work head, a grinding wheel on the wheel head, automatic means for cyclically shif ting the work head and wheel head toward and from one another, a pressure roll for yieldably holding the work on the work support, an oscillatable carrier for the pressure roll, a sizing mechanism carried by the work head for engagement with the grinding wheel at the conclusion of the grinding Voperation and effecting the relative retraction of the wheel head and work head, and means controlled by the pressure roll oscillatable carrier for ladjusting the position of the sizing mechanism relative to the wheel and Work for thereby insuring successive work pieces, having the same size bore therein.

5. In an internal grinder of the class described the combination of a bed, a work head mounted thereon for movement relative thereto, a wheel head mounted on the bed for movement relative thereto, a work support on the work head, a grinding wheel on the wheel 6.5 head, automatic means for cyclically shifting a cam having a cam face for eng ement with the work head and wheel head toward and from one another, a Eressure roll for yieldably holding the wor on the work support, anoecillata le carrier for the Eressure roll a sizing mechanism carried by t e work head for engagement with the (grinding wheel at the conclusion of the grin mg operation and eifectm the relative retraction of the wheel head an work head, and means controlled b the pressure roll oscillatable carrier for a )ustmg the position of the sizing mechanism relative to the wheel and work for thereby insuring successive work ieces having the same size bore therein, said) means includin a cam having a cam face for engagement witg the pressure roll bracket and having a second cam face for engagement with the sizing mechanism and shifting same thereby. 6. In an internal grinder o'f the class described the combination of a bed, a work head mounted thereon for movement relative thereto, a wheel head mounted on the bed for movement relative thereto, a work support on the work head, a grindin wheel on the wheel head, automatic means or cyclically shifting the work head and wheel head toward and from one another, a pressure roll for yieldably holding the work on the work support, an oscillatable carrier for the ressure roll, a sizing mechanism carried by t e work head for en agement with the inding wheel at the conc usion of thegrin ing operation and effecting the relative retraction of the work head and wheel head, means controlled bythe pressure roll oscillatable carrier for ad]usting the position of the sizing mechanismV relative to the wheel and work for thereby insuring successive work pieces having the same size hole therein, said means including 1.05 the pressure roll bracket and havlng a second cam 'face for engagement with the sizin mechanism and shifting same thereby, an

yielding means for maintaining contact between the sizing device and its cam face.

7. In a device of the class described the combmation of a work support, a friction drive wheel on one side of the work support and contacting with a work piece on -the support, a pressure roll on the other side of the work support for engagement with the work, a bracket pivotally supporting the pressure roll for oscillatory movement toward and from the work, yielding means for holding said pressure roll against the work for holding same in contact with the Awork support and friction drive wheel, a cam having a pair of cam surfaces thereon, means supporting the cam for oscillatory movement and with one cam face en aging with the pressure roll bracket, a grin ing wheel for operation on the bore of the work, means for effecting a relative feed between the grinding wheel and work, a sizing mechanism for interrupting said feed, and means connecting the sizing i? mechanism with the second c'am face for adjusting said sizing mechanism an amount to properly osition the sizing device relative to the grin ing wheel and determined by the` C movement of the pressure roll bracket toward the work to eiect engagement between the roll and work.

8. In a sizing mechanism of the class described the combination of a work support adapted to peripherally engage the work during operation thereon, a friction drive Wheel on one side of the work support for engaging the work and controlling its rotation, a pressure roll on the other side of the work support for engaging the work and holding same in contact with the support and friction drive wheel, yielding means for oscillating the pressure roll toward the work, hydraulically actuable means for retracting the ressure roll against its yielding means, a grinding wheel for operation on the work` means for effecting a. relative feed between the wheel and work, a sizing mechanism for interrupting said feed, means supporting the sizing mechanism for movement relative to the work 'toward and from the grinding wheel, yielding means for urging the sizing mechanism in one direction, positive means for shifting the sizing mechanism in the other direction, and an operative coupling between the pressure roll and sizing mechanism whereby they are simultaneously shifted relative to the Work for respectively holding the Work in the grinding throat and positioning the sizing device in accordance with the particular size of the work on the support.

9. In a sizing mechanism of the class described the combination of a work vsupport adapted to peripherally engage the work during operation thereon, a friction drive wheel on one side of the work support for engaging the work and controlling its rotation, a pressure roll on the other side of the work support for engaging the work and holding saine in contact with the support and friction drive Wheel, yielding means for oscillating the pressure roll toward the work, hydraulically a-ctuable means for reti'acting the pressure roll against its yielding means, a grinding wheel for operation on the work, means for effecting a relative feed between the wheel and work, a sizing mechanism for interrupting said feed, `means supporting the sizing mechanism for movement relative to the work toward and from the grinding Wheel, yielding means for urging the sizing mechanism in one direction, positive means for shifting the sizing mechanism in the other direction, an operative. coupling between the pressure roll and sizing mechanism whereby they are simultaneously shifted relative to the work for respectively holding the work in the grinding throat and positioning the sizing device in accordance with the particular size of 55 the work on the support, said means comprising a cam having a air of camfaces thereon, one of said cam aces adapted to contact with the pressure roll, the other'of said cam faces adapted to contact with the sizing mechanism, and h draulically actuated means for rotating sai cam and shifting said sizing device.

10. In a sizin mechanism of the class described the com ination of a work support adapted to peripherally engage the work during operation thereon, a. friction drive wheel on one side of the work support for engag ing the work and controling its rotation, a pressure roll on the other side of the' work support for engaging the work and holding same in contact with the support and friction drive wheel, yielding means for oscillating the pressure roll toward the work, hydraulically actuable means for retracting the pressure roll against its yielding means, a grinding wheel for operation on the work, means for effecting a. relative feed between the wheel and work, a sizing mechanism for interrupting said feed, means supporting the sizing mechanism for movement relative'to the work toward and from the grinding wheel, yielding means for urging the sizing mechanism in one direction, 'positive means for shifting the sizing mechanism in the other direction, an operative coupling between the pressure roll and sizing mechanism whereby they are simultaneously shifted relative to the work for respectively holding the work in the grinding throat and positioning the sizing device in accordance with the particular size of the work on the support, said means comprising a cam having a pair of cam faces thereon, one of said cam faces adapted to Contact with the pressure roll, the other of said cam faces adapted to contact with the sizing mechanism, hvdraulically actuated means for rotating said ,cam and shifting said sizing device, and means for connecting the hydraulic mechanisms of the pressure roll retracting means and cam rotating means to insure timed sequential movement thereof.

11. In a mechanism for interrupting the feed between a work piece and grinding wheel when the hole therein is reduced to the desired size the combination with a work receiving throat comprising opposed friction drive wheel and pressure roll forming the throat and having a work rest blade therein, of means for supporting one of these parts for oscillatory movement toward and from the remaining parts and together constituting a caliper for measuring the work within the throat, a feeding mechanism for actuating the grinding wheel and the work relative to one another, a sizing mechanism for interrupting this feed, land means for adjusting the position of the sizing mechanism relative to the throat to position saine in accordance with the size of the work as determined by the caliper members.

12. In a mechanism for interrupting the feed between a work piece and grinding wheel when the hole therein is reduced t0 the desired size the combination with a work receiving throat comprising opposed friction drive wheel .and pressure roll forming the throat and having a work rest blade therein, of means for supporting one of these parts for oscillatory movement toward and from the remaining parts and together constituting a caliper for measuring the work within the throat, a feeding mechanism for actuating the grinding wheel and the work relative to one another, a sizing mechanism for interrupting this feed, means for adjusting the position of the sizing mechanism relative to the throat to position same in accordance with the size of the work as determined by the caliper members, said means comprising a cam having a pair of cam faces thereon and which bear a varying rising relationship to one another, the larger cam rise face being adapted to contact with the shiftable caliper .member, while the relnaining face is adapted to engage the sizing mechanism, and means for rotating the cam after the work piece is within the throat, which rotation is stopped by engagement of the cam face with the caliper member.

13. In a mechanism for interrupting the feed between a work piece and grinding wheel when the hole therein is reduced to the desired size the combination with a work receiving throat comprising opposed friction drive wheel and pressure roll forming the throat and having a work rest blade therein, of means for supporting one of these parts for oscillatory movement toward and from the remaining parts and together constituting a caliper for measuring the work within the throat, a feeding mechanism for actuating the grinding wheel and the work relative to one another, a sizing mechanism for interrupting this feed, means for adjusting the position of the sizing mechanism relative to the throat to position same in accordance with the size of the work as determined by the caliper members, said means comprising a cam having a pair of cam faces thereon and Which bear a varying rising relationship to one another, the larger cam rise face being adapted to contact with the shiftable caliper member, while the remaining face is adapted to engage the sizing mechanism, means for rotating the cam after the work piece is within the throat, which rotation is stopped by engagement of the cam face with the caliper member, the varying ratio between the cam faces effects a shifting of the sizing mechanism one-half of the distance that the throat member moves and thereb insures the proper positioning of the sizing evice relatlve to the wheel and work regardless of the outside diameter of the work.

14. In a mechanism for interrupting the feed between a work piece and grinding wheel when the hole therein is reduced t0 the desired size the combination with a work receiving throat comprising opposed friction drive wheel and pressure roll forming the throat and having a work rest blade therein, of means for supporting one of these parts for oscillatory movement toward and from the remainin parts and together constituting a caiper for measuring the work within the throat, a feeding mechanism for actuating the grinding wheel and the work relative to one another, a sizing mechanism for interrupting this feed, means for adjusting the position of the sizing mechanism relative to the throat to position same in accordance with the size of the work as determined by the caliper members, said means comprising a cam having a pair of cam faces thereon and which bear a varying rising relationship to one another, the larger cam rise face being adapted to contact with the shiftable caliper member, while the remaining face is adapted to engage the sizing mechanism, means for rotating the cam after the work piece is within the throat, which rotation is stopped by engagement of the cam face with the caliper member, the varying ratio between the cam faces effects a shifting of the sizing device one-half ofthe distance that the throat member moves and thereby insures the proper positioning of the sizing mechanism relative to the wheel and work regardless of the outside diameter of the work, and yielding means for maintaining Contact between the sizing mechanism and its cam face.

In testimony whereof, I affix my signature.

LESTER F. NENNINGER.

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