US1891657A - Grinding machine - Google Patents

Description

Dec. 20, 1932. F. J. THELER 1,891,657

GRINDING MACHINE Filed Aug. 6. 1931 4 Shuts-Sheflt 1 Gttomcu Dec. 20, 1932. J, THELER 1,891,657

' GRINDINGMACHINE Filed Aug. 6. 1931 4 Sheets-Sheet 2 Zhmentor Dec. 20, 1932. F. J. THELER 1,891,657

GRINDING MACHINE Filed Aug. 6. 1931 4 3119684110" 3 if? I I 1 wall 15/ a? 154 4/1 M/M/M/MA A X/l/////i JIM 1! All; 3

3nventor Dec, 20, 1932.

Filed Aug. 6. 1931 4 Sheets-Sheet 4 Snpentor 409 FQWA /cWJ/Z fi/A J 38 WW (Ittorneg Patented Dec. 20, 1932 UNITED STATES.

PATENT" OFFICE FREDERICK J. THELER, OF CINCINNATI, OHIO, ASSIGNOR TO CINCHINATI GBINDEBS INCORPORATED, 0F CINCINNATI, OHIO, A CORPORATION 01 OHIO GRINDING MACHIN E Application filed August a, 1931. Serial No. 555,576.

This invention relates to improvements in grinding machines and especlally to 1m-' provements in an automatic grinder.

An object of the invention is the provision of an improved automatic grinding mach ne for grinding the exterior surfaces of work pieces concentric to the here or ax s thereof.

Another object of the inventlon .is the proautomatically from a hopper or like mechamsm.

A further object of the invention is the provision of a grindin machine in which the loading time is reduced to a minimum and the productive hours increased to a maximum.

Another object of the invention is the provision of an' improved external grindenfor grinding cylindrical work pieces and utilizing an improved work driving mechanism which automatically engages and rotates the work without the use of dogs, or the like.

Other objects and advantages of the present invention should be readily apparent by reference to the following specification con-. sidered in conjunction with the accompanying drawings and it is to be understood that any modifications may be made in theexact structural details there shown and described, within the scope of the appended claims, without departing from or exceeding the spirit of the invention.

In the drawings:

Figure 1 is an elevational view of a grinding machine embodyingthe improvements of this invention. 1

Figure 2 is a top plain view of the machine shown in Figure 1.

Figure 3 is an elevational view through the throat of the grinding machine, certain parts being shown in cross section.

Figure 4 is a view similar to Figure 3 but in section and taken on line 4-4 of Figure 2.'

Figure 5 is a sectional view on line 5-5 of Figure 3.

Figure 6 is aview taken on line 6-6 of F igure 3, certain parts being shown in elevation and others in section.

' Figure 7 is a sectional view taken from line 77 of Figure 2.

Figure" 8 is a sectional view taken on line 88 of Figure 7 Figure 9 is a sectional view on line 9-9 of Figure 8.

Figure .10 is a fragmentary sectional view taken-on linelO-lO of Figure 8. vision of an external grinding machine.auto-. matically operated and adapted to be loaded- Figure 11 is a sectional view longitudinally of the -machine through the friction drive A machine embodying this invention may comprise a base or bed 15 having risin therefrom at one end thereof a pedestal earing 16 for a spindle 17 to which is secured the grinding wheel 18 for rotation in a clockwise direction at a high grinding rate of speed. The bed 15 is further formed on its upper surface with a guideway 19 for a slide 20 mounted thereon and shiftable longitudinally of the bed. Superimposed on the slide 20 is a second slide '21 carrying head 22 in which is journaled a spindle 23 for a wheel 24 hereafter referred to as the friction drive wheel. The proximate points of the grinding wheel 18 and friction drive wheel 21 are spaced from one another a distance corresponding to the final size of the work.

The slides 20 and 21 are adapted to. be shifted relative to one another when settingup the machine for operation on a given size of work or they are adapted to be shifted as a unit relative to the bed 15 for effecting a relative feed between the work and grinding wheel. For this purpose there is provided an adjusting screw 25 having its threaded end received in a nut .26 mounted'in the rear wall of the upper slide 21. The screw 25 is rotatably j'ournaled in a housing 27 andextends therebeyond to which is secured a pilot or hand wheel 28. In order that the upper slide 21 may be moved relative to the lower slide 20, clamps 29 are provided for fastening The lower slide 20 is provided at its inner ing throat and bears the work supporting members. As seen in Figures 3 and 4, the block 31 is provided with a rotatable turret head 32 having a plurality of work spindles 33 projecting therefrom. The spindles 33 are mounted in antifriction bearings 34 secured in suitable bores in the head 32. Each spindle is provided with a tapered nose 35 for entering the bore in the work 36. The spindles 33, adjacent the tapered nose 35, are provided with a plane bearing portion 37 which fits the bore of the work at that end.

The turret head 32 is secured to a shaft 38 journaled at opposite ends in uprights 39 and 40 which are secured to and extend upwardly from the block 31. The turret 32 has a loading station and an operating station at points diametrically opposite one another. Opposed to the center in the operating station is a tailstock center 41 which is similar to the centers or spindles 33 and has a tapered nose 42 and a'bearing surface 43 for the work. The inner end of the center or spindle 41 is mounted on antifriction bearings 44 carried by the sliding sleeve 45. The sleeve 45 is slidably actuated through a suitable bore formed in a tailstock or support 46. This sup.- port 46 is mounted on the bracket or block 31 of the lower slide. A key 47 is carried by the bracket 31 and received in a keyway 48 in the support 46, to insure alignment of the spindle 41 with the turret spindles 33.

The tailstock or support 46 may be adjusted longitudinally of the bracket 31 toward and from the turret 32 by means of a screw 49 rotatably journaled in 9. lug 50 of bracket 51 secured as by cap screws 52 to the said block or bracket 31. This adjustment of the support 46 enables the grinding of work pieces of different lengths. The support or tailstock 46 is provided on opposite sides with a'longitudinal flange 155 having elongated perforations 156 therein through which clamp bolts 157 extend into the block or bracket 31 for clamping the support or tailstock 46 in adjusted positions.

In order to insure the proper positioning of the work pieces 36 on the spindles 33 and to insure the work contacting with the stop shoulder 158 on each spindle, there is provided a guard or positioning band 159. As seen in Figure 3, the free endof the guard 159 is flared as at 160, so that should a work piece or pieces extend beyond the proper point they will be forced onto the spindles by the camming action of the said flared end 160. The guard is held in place by a bracket 161 secured to the support or tailstock 46, as well as by brackets 162 and 163 respectively carried by the upright -40 and block or bracket 31. The guard 159 has a perforation 164 therein through which the center or spindle projects. This perforation is somewhat larger than the diameter of the spindle but is of a diameter less than that of the adjacent end of the work. Therefore, if the work tends to stick to the spindle 41 as it is being retracted the guard surrounding the perforation acts to strip the work from the center.

The bracket 31 is further provided at opposite ends on one of its vertical faces with hearing lugs 53 and 54 in which is slidably mounted a rod 55. The rod 55 carries near its rear end the cam 56 having an inclined cam face 57. The rod 55 carries near its other end the upstanding post 58 having an elongated perforation 59 therein receiving a pin 60 from the lever 61. The cam face 57 on the cam block 56 is adapted to engage and oscillate a lever 62 which is fast on a shaft 63 extending transversely through the tailstock or support 46. Also, secured to the shaft 63 for movement therewith is an arm 64 which has its upper end bifurcated, as at 65, to receive a pin 66 extending from the sliding sleeve 45 through an elongated perforation 67 formed in the support 46. The lever 61 is rotatably journaled on the shaft 38 and lies against the outer face of the upright 40. Pivoted at 68 to the lever 61 is a pawl 69 actuated by spring 70 toward the ratchet 71 secured by cap screws or the like 72 to the end of the shaft 38.

The rod 55 is adapted to be actuated to the left, as seen in Figure 3, for indexing the turret head 32 to place an unfinished work piece in the throat of the grinder. The operation of these parts is as follows: Movement of the rod 5 5 to the left first effects an engagement between the cam face 57 and the arm 62 which actuates said arm in a clockwise direction about the axis of the shaft 63. This effects a retraction of the spindle 41 from the work 36. Continued movement of the rod 55 to the left eventually takes up the lost motion between the nose 73 of the pawl 69 and the next tooth 74 of the ratchet 71. At this time the ratchet is advanced 45 to the next station whereupon the rod 55 is actuated to the right. A locking mechanism, subsequently to be described, locks the turret in such adjusted position so that the said movement of the rod 55 to the right causes the pawl 69 to ride on top of the teeth of the ratchet 71. Also, as the cam block 56 backs away from the lever 62 a spring 75, which was compressed during the retracting of the spindle 41, expands to actuate the sleeve 45 to the left, as seen in Figure 4, for placing the center 41 within the adjacent end of the new unfinished work 36. The spring 75 is received in a suitable bore in the sleeve 45 and abuts on its one end with a shoulder 76 at the base of the bore and on its other end with a head 77 on tension adjusting screw 7 8.

The Work, after being finished, is carried downwardly in an arcuate path by the turret head 32 through an arcuate chamber 165 formed in the block or bracket 31 beneath the turret head 32, see Figures 4 and 5. Positioned on the upper surface of the block or bracket 31 and partially overlying the chamher 165 is a pair of strips 166 and 167 spaced from one another to form a passage 168 therebetween. The passage 168 is of a width slightly wider than the diameter of the body portion of the work but less than the diameter of the enlarged collar portion 169 on the work whereby the said strips 166 and 167 are adapted to engage the shoulder formed by the collar 169 and strip the work from the turret spindles 33 in the event the work tends to stick thereto.

The locking mechanism, above referred to, comprises a spring loaded plunger 79 slidably mounted in a lug 80 projecting from one side of the upright 40. The plunger 79 has on its outer end a roller 81 adapted to be engaged by the cam face 82 of spring loaded cam block 83 pivoted at 84 to an extending tail 85 of the post 58. The plunger 79, under the force of a spring 86, mounted thereabout, enters successive pockets 87 formed in the adjacent face of the turret 32. As the bar 55 moves to the left, as seen in Figure 3 and as above described, the cam face 82 engages the roller 81 for shifting the plunger 79 from the pocket 87 whereupon the turret is in condition to be indexed. Continued movement of the bar 55 commences the indexing of the turret whereupon the roller passes the cam block 83 under the influence of the'spring 86 which holds the plunger against the said adjacent face of the turret 32 so that as soon as the next pocket is aligned therewith it is snapped in.

The work is fed into the grinding wheel by shifting the lower slide and the parts carried thereby toward the grinding wheel. This is accomplished automatically by the mechanism illustrated in Figures 7 to 10 inclusive. As there shown the adjusting screw 25 has secured to it at a point interiorly of the housing 27 a sliding block 88 by means of collars 89 and 90 flanking the ends thereof. The slide block is mounted in a bearing 91 extending inwardly from the side wall of the housing 27 and the said slide block has pivoted to its opposite sides links 92, in

turn, pivoted at the opposite ends to lugs 93 of bell crank lever 94 pivotedat 95 to the casing or housing 27 The depending arm 96 of the bell crank 94 has adjustably secured thereto a roller 97 mounted in a cam track 98 of cam 99. This cam 99 is secured to'one end of worm shaft 100 having secured to it intermediate its ends the worm wheel 101 meshing.

with worm 102. The worm 102 projects through the casing 27 and is geared, as at 103, to a prime mover 104 secured to the bottom of the housing 27, as shown in Figure 1.

From the foregoing it will be noted that, due to the particular contour of cam groove 98, the screw 25 is first shifted toward the left at a rapid rate to take up the space between the work and grinding wheel. The screw is then further shifted toward the left at a comparatively slower rate to effect the desired and necessary stock removal from the work which is followed by a dwell in the movement of the parts to permit a complete rounding up of the work and a sparking out of the grinding wheel. This dwell is immediately followed by a rapid retraction of the screw so that the finished work piece may be replaced by an unfinished one.

To effect a timed sequential operation of the work supporting and indexing mechanism and the automatic feeding cycle there is mounted on the other end of the worm shaft 100 a second cam 105 having a cam face groove or track 106 which receives the roller 107 carried by a lever 108 intermediate its end. The lever 108 is pivoted at 109 to the casing 27 and has a pin and slot connection 110 at its other end with a valve stem 111. The valve stem 111 is integral with a spool type sliding Valve 112 axially shiftable through a sleeve or bushing 113 for connecting a hydraulic medium under pressure with either conduits 114 or 115. The conduits 114 and 115 terminate at the opposite ends of a h draulic cylinder 116 secured by any suitable means to the face of block or bracket 31 opposite to that along which the rod 55 moves. The cylinder 116 houses a piston 117 from which a rod 118 extends. The rod 118 is pivoted at 119 to one end of lever 120 pivoted intermediate its ends to the bracket 51 secured to the block 31. The other end of the lever 120. is pivoted at 121 to the sliding rod 55 and whereby movement of the piston 117 effects an opposite sliding movement of the rod 55.

The cam groove or track 106 bears a definite relation to the cam groove or track 98 so that the piston 117 is actuated to operate the work indexing and supporting centers at the time that the lower slide 20 is retracted whereby sufiicient clearance is established between the work and grinding wheel to permit indexing thereof without endangering the nection between the work and friction driving wheel at the time that the work is indexed from the unfinished station to the finished station, as well as from the finished station to the unloading point, a lost motion connection is provided between the upper and lower slides 20 and 21. This lost motion connection consists of a lug 122 receiving a link 123 attached to one end of spring 124 which has its other end secured as at, 125 to the lower slide 20. From this it will be seen that a rearward pull on the upper slide 21 will, through the spring connection, carry with it the slide 20. This movement continues until an adjustable stop in the nature of screw 126 carried by lug 127 standin upwardly from the bed is encountered w ereupon the slide 21 moves beyond the sl de tensioning the sprlng 124. Reverse shifting or a push on the slide 21 will take up the ten sion of the spring 124 whereupon the slides will move as a unit relative to the bed 15, as above described.

To maintain proper friction contact between the friction drive Wheel 24 and the work 36 the wheel is of the yielding type, which consists of a spider 128 surrounding the spindle 23 having a series of pockets 129 therein receiving coiled springs 130. The coiled springs 130 abut on their other ends with driving lugs 131 entering suitable notches 132 formed in the ring 133 about which abrasive ring-or wheel 24 is formed. It will be understood that as the surface of the work is ground away the tendency will be for it to recede from the surface of the ring or wheel 24 and since the expansion of spring 124 is taken up initially no additional relative movement between slides20 and 21 is provided. Therefore, as the said surface of the work recedes, the springs 130, which were initially placed under tension by displacing the surface of the wheel relative to the axis of the spindle, expand to follow up the said receding surface.

As was noted above, the work is loaded on the spindle at a point diametrically opposed to the grinding point. This work is automatically placed thereon from a suitable hopper 134 adjacent the grinding throat and eX- teriorly thereof. The hop or 134 forms no part of this invention, it being self-contained but tripped or operated in timed relation with the feeding and indexing mechanisms. The hopper 134 terminates in a feed slide 135 and a pusher 136 thereon for pushing the work from the slide 135 on the spindles 33 as they are successively aligned therewith. The hopper mechanism is tripped or set in motion by a link 137 pivoted at 138 to a lever 139 on the end of a shaft 140 journaled in bearing 141 carried by a projecting ledge of block or bracket 31. The shaft 140 extends along the front of the bed 15 and is journaled at its opposite end in bearings142 of the housing 27. Secured to the shaft 140 interiorly of the housing 27 is a single tooth ratchet or plate 143 receiving the nose 144 of slidable pawl 145. This pawl 145 is adapted to be 'slidably actuated through a bearing 146 in the lever 147 has projecting from it a lug 153 adapted to cooperate with a lug 154 extending from the inner face of cam 99.

Rotation of the cam causes the lugs 153 and 154 to engage one another for actuating the lever 147 in a clockwise direction, as seen in Figure 10, about the axis of pivot 148 thereby tensioning the spring loaded plunger 150, and, through the interengagement of lugs 151 and 152, shifts the pawl 145 to the right, as seen in Figure 10. This movement of the pawl 145 rotates the shaft 140 and causes a tripping or actuation of the pusher 136 to place the work piece on the feed slide 135 on the turret spindles 33 next inclined to receive an unfinished work piece. As soon as the lugs 153 and 154 pass from under one another expansion of spring loaded pawl 150 retracts the shaft 140 and effects the deposition of a new work piece on the slide 135 ahead of the pusher 136 for the subsequent operation thereof.

\Vhat is claimed is:

1. In a grinding machine the combination of a bed, a grinding wheel'rotatably mounted thereon, an opposed friction drive wheel spaced from the grinding wheel for providing a grinding throat therebetween, an indexible turret supporting work pieces in the grinding throat in simultaneous engagement with the grinding wheel and friction drive wheel, and additional supporting means in the grinding throat cooperating with the turret for supporting work pieces.

In a grinding, machine the combination of a bed, a grinding wheel rotatably mounted thereon, an'gopposed friction drive Wheel spaced from the grindingwheel for providing a grinding throat therebetween, an indexible turret supporting work pieces in the grinding throat 1n simultaneous engagement -for supporting work pieces, and means cf.-

fecting a. relative feed between the work and grinding wheel to effect a stock removal from the work.

l 3. In a grinding machine the-combination of a bed, a grinding wheel rotatably mounted thereon, an opposed friction drive wheel spaced from the grinding wheel for providing a grinding throat, therebetween, an indexible turret supporting work pieces in the grinding throat in simultaneous engagement with the grinding wheel and friction drive wheel, additional supporting means in the grinding throat cooperating with the turret for supporting work pieces, means effecting a relative feed between the work and grinding wheel to effect a stock removal from the work, and means for automatically placing work pieces on the indexible turret.

4. In a grinding machine for grinding the exterior surface of work pieces concentric with a previously formed internal bore the combination of a bed, a grinding wheel rotatably mounted thereon, a friction drive wheel opposed to the grinding wheel and spaced therefrom to form a grinding throat, an indexible turret head having a plurality of s indles adapted to enter the bore in the wor and carry said work from a loading position to the grinding throat, means for automatically placing the work on the turret spindle, and additional means cooperating with the turret spindles for supporting the work within the grinding throat in simultaneous engagement with the grinding wheel and friction drive wheel whereby the grind ing wheel effects a stock removal from the work while it is being rotated by the fric tion drive wheel about an axis determined by the bore in the work.

5. In a grinding machine for grinding the exterior surface of work pieces concentric with a previously formed internal bore the combination of a bed, a grinding wheel rotatably mounted thereon, a. friction drive wheel opposed to the grinding wheel and spaced therefrom to form a grinding throat, an indexible turret head having a plurality of spindles adapted to enter the bore in the work and carry said work from a loading position to the grinding throat, means for automatically placing the work on the turret spindle, additional means cooperating with the turret spindles for supporting the work within the grinding throat in simultaneous engagement with the grinding wheel and friction drive wheel whereby the grinding wheel effects a stock removal from the work while it is being rotated by the friction drive wheel about an axis determined by the bore in the work, and means for automatically stripping the work from the spindles at the conclusion of the grinding operation.

6. In a grinding machine for grinding the exterior surface of work pieces concentric with a previously formed internal bore the combination of a bed, a grinding .wheel rotatably mounted thereon, a friction drive wheel opposed to the grinding wheel and spaced therefrom toform a grinding throat, an indexible turret head having a plurality of spindles adapted to enter the bore in the workand carry said work from a loading position to the grinding throat, means for automatically placing the work on the turret spindle, additional means cooperating with the turret spindles for supporting the work within the grinding throat in simultaneous engagement with the grinding wheel and friction drive wheel whereby the grinding wheel effects a stock removal from the work while it is being rotated by the friction drive wheel about an axis determined by the bore in the work, means for automatically stripping the work from the spindles at the conclusion of the grinding operation, and additional means for automaticall indexing the turret to remove the finishe work piece from the grind ing throat andplace an unfinished one therein.

7. In a grinding machinethe combination of a bed, a grinding wheel rotatably carried by the bed, a slide carried by the bed and movable toward and from the grinding wheel, a rotatable friction drive wheel on the slide in opposition to the grinding wheel and forming a grinding throat therebetween, a turret carried by the slide indexible in a plane transversely of the grinding throat, a plurality of spindles on the turret adapted to enter the bore in the work, means for intermittently indexing the turret to successively place the work pieces within the grinding throat and remove same therefrom, and a retractable spindle opposed to the turret spindles when within a grinding throat and cooperating therewith to support the work piece for rotation.

8. In a grinding'machine the combination of a bed, a grinding wheel rotatably carried by the bed, a slide carried by the bed and movable toward and from the grinding wheel, a rotatable friction drive wheel on the slide in opposition to the grindin wheel and forming a grinding throat there etween, a turret carried by the slide indexible in a plane transversely of the grinding throat, a plurality of spindles on the turret adapted to enter the bore in the work, means for intermittently indexing the turret to successively place the work pieces within the grinding throat and .work, means for retracting the tailstock spindle at the conclusion of the grinding operation, and means synchronizing the shifting of the slide toward and from the grinding wheel and the indexin of the turret and retraction of the tailstoc spindle.

9. In an automatic grinding machine for grinding the exterior surface of hollow work pieces concentric with the axis of the bore the combination of a bed, a pair of opposed grinding and friction drive wheels carried thereby and forming a-grinding throat therebetween, a slide for one of the wheels whereby it may be actuated toward and from the other wheel, indexible means having work supports thereon o erable in a plane transversely of the grin ing throat to place work pieces in and. remove same from the said abrasive wheel, yielding means for terminal ly engaging the work while adjacent the wheel, and means automatically retracting the terminal means prior to the indexing of the turret. A

17. In a machine tool organization the Combination of a bed, an abrasive wheel rotatably mounted thereon, an indexible carrier for positioning work pieces adjacent the abrasive wheel. yielding means for terminally engaging the work while adjacent the friction drive means for rotating the Work while in contact with the wheel.

19. In a machine tool-organization the combination of a bed, an abrasive wheel. rotatably mounted thereon, indexible means for positioning work pieces adjacent the.

operative face of the wheel. means terminally engaging the work adjacent the wheel, friction drive means for rotating the Work while in contact with the wheel, means automatically separating the terminal engaging means prior to the indexing of the turret, and means discharging the work from the turret.

20. In a machine tool organization the combination of a bed, an abrasive wheel rotatably mounted thereon, a turret supporting a plurality of work pieces indexible toposition successive pieces in operative rela tion with the wheel. terminal means supporting the work adjacent the wheel including a center yieldably shifted toward the work, and friction drive means for rotating the work while terminally supported in contact with the wheel.

21. In a machine tool organization the combination of a bed, an abrasive wheel rotatably mounted thereon. a turret supporting a plurality of work pieces indexible to position successive pieces in operative relation with the wheel, terminal means sup porting the work adjacent the wheel including a center yieldably shifted toward the Work, friction drive means for rotating the work while terminallv supported in contact with the wheel, and means automatically retracting the center against the yielding resistance of the center projecting yielding means.

22. In a machine tool organization the combination of a bed, an abrasive wheel rotatably mounted thereon, a turret supporting a plurality of work pieces indexible to position successive pieces in operative rela tion with the wheel, terminal means supporting the work adjacent the wheel including a center yieldably shifted toward the Work, friction drive means for rotating the Work while terminally supported in contact with the wheel, means automatically retracting the center against the yielding resistance of the center projecting yielding means, and means automatically placing work pieces on the turret.

In testimony whereof I aflix my signature.

FREDERICK J. THELER.

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