US1339860A - Cross-feed mechanism for grinding-machines - Google Patents

Description

C. H. NORTON, A. TURNER AND]. S. WILCOX, In. I

CROSS FEED' MECHANISM FOR GRINDING MACHINES.

APPLICATION FILED IUNE2 71 19-H- ISIIEETS-SHEET Pfitented May 11,1920.

V5440? war- 22221927 C. H. NORTON, A. TURNER AND 1 S. WILCOX, Jn. cnoss FEED MECHANISM FOR GRINDINGMACHINES.

APPLICATION FILED JUNE 27-. WW.

1 339 Q Patented May 11, 1920.

ISHEETS-SHEET 2.

- k s I u 1 IIIIIIIIIIIIIIIIIIIIII C. H. NORTON, A. TURNER AND J. S. W|LCOX, JR.

CROSS FEED MECHANISM FOR GRINDING MACHINES.

APPLICATION FILED JUNE 27., I917.

. w x m M w w Q I w I|I I I III W M L I I L rn m A m @w 5% 5 d I I v m @QN w w m as P e a C. H. NORTON, A. TURNER AND J. S. WILCOX, In. CROSS FEED MECHANISM FOR GRINDING MACHINES.

APPLICATION FILED JUNE 27, 1917.- I

Patented May 11, 1920.

I SHEETS-SHEET QQN MUN NEW IQNN RQN

IIIIIIIII VIII/III C. H. NORTON, A. TURNER AND J. S. WILCOX, JR.

CROSS FEED MECHANISM FOR GRINDING MACHINES.

APPLICATION FILED lumzzl. I917.

1.,v3i29,860. Patented May 11,1920.

7SHEETSSHEET 5.

C. H. NORTON, A. TURNER AND J. S. WILCOX, In.

caoss FEED MECHANISM FOR GRINDING MACHINES.

APPLICATION FILED JUNE 27, I9I7.

Patented May 11, 1920.

7SHEETSSHEET 6 w y 2 QQ n w m ii MN h RN mw QQ a QNN I NwN N J .QNNI \I IIIII NNNIIII IIHIH IIMII I- QQN NNN wm www MN M .QN mw II.. 3W I O s S w m gIr C. H. NORTON, A. TURNER AND I. S. WILCOX, .IR.

CROSS FEED MECHANISM FOR GRINDING MACHINES.

Patented May 11, 1920.

APPLICATION FILED JUNE 2?. 1917.

UNITED STATES PATENT. OFFICE.

CHARLES H. NORTON, ALBERT TURNER, AND JOSEPH S. WILCOX, JR., 0 WORCESTER,

MASSACHUSETTS, ASSIGNORS, BY MESNE ASSIGNMENTS, TO NORTON COMPANY, OF WORCESTER, MASSACHUSETTS. A CORPORATION OF MASSACHUSETTS.

(moss-FEED MECHANISM FOR emnnme-macnmns.

" Application filed June 27,

H2 all whom atmay concern Be it known that we, CHARLES H. NORTON, ALBERT TURNER, and JOSEPH S. WILoox, J r., citizens of the United States, residing at Worcester, .in the county of Worcester and State of Massachusetts, have invented a new and useful Cross-Feed Mechanism for Grinding-Machines, of which the following is a specification.

This invention relates to a cross feed mechanism and is particularly designed for use in a cylindrical grinding machine.

For certain-types of grinding operations it is desirable to use wheels of relatively soft gradein which the bond between the cutting particles gives away readily and allows dulled, useless grains tobreak off, thereby presenting new and sharp surfaces in constant succession, as the cutting proceeds, and permitting a more rapid rate of action. However, due to the softness of the bond, if the wheel is fed toward the work too rapidly, there is a marked tendency for the fillets or corners of the wheel to break down, or for the wheel to become impaired in other ways. -When the feed is by hand and within the control of the operator, subject to his whims or carelessness, and is too slow at one time and then at another is too rapid to make up for lost'time, the net result is imperfect work or heavy wear and tear on the machineand the grinding wheel.

Furthermore, in the semi-automaticallyoperated grinding machines heretofore known, the wheel feed has been intermittent in operation, a ratchet and pawl feed being commonly used. In order to feed the wheel forward by pawl and ratchet it is necessary to move it rapidly during a portion of the grinding period and too deeply into the work, causing the wheel to be subjected to the strains of heavy grinding which grade ually diminishes as the material i cut away until the feed is again operatec and the cycle repeated. 7 1

In accordance withour invention, an absolutely uniform feed is provided during the grinding operation so that the wheel may be moved continuously at a predetermined rate and much slower than when fed intermittently 'toaccomplish the same re- Specification of Letters Patent;

Patented May 11, 1920.

1917; Serial No. 177,350.

anism for relative movement of' grinding wheel and work which will be entirely automatic in operation and which will feed the wheel into the work at a constant uniform and predetermined rate of cutting that is not subject to variation by the operator durmg a. given grinding operation after the wheel has been brought into cutting contact with the work. 'At the same time the, operator may decide which one of several uni-- form rates of speed shall be utilized, and he may manually control the mechanism to the extent of changingv from one speed to another'or stopping or reversing'the feed, although he cannot vary the rate momentarily and he cannot feed the work by hand during the grinding period, before an automatic feed stopping mechanism has been brought into action .Our broad invention consists, therefore, in the provision of-an exclusively automatic cross feeding mechanism particularly adapted for cylindrical grinding machines.

In grinding operations, particularly when performed upon rough castings or for ings, it is found desirable to provide three 'iferent predetermined feeds "including" a fast feed for bringing the wheel forward to a point adjacent the work, an intermediate feed .for use in grinding 'off irregular projections or fins upon the forging or casting, and a comparatively slow or fine feed for use when the grinding wheel begins to cut into the solid-body of the stock. Accordingly, an important feature of our invention relates to the provision of improved mechanism by which a plurality of predetermined rates of cross feed may be ob-' tained, these several rates'being under the selective control ,of the operator. .This. mechanism is entirely distinct from the provision cornmonly' made for a general increase or decrease in the speed of the entire cross-feeding mechanism as by a cone pulley on the driving shaft.

Another important feature of our invention relates to new and improved devices by which the cross feed may be thrown out of action at a fixed point predetermined with a very high degree of accuracy. 7

In the preferred form, this feature of our invention comprises a stop, a stop-engaging member mounted to permit a partial rotation, a clutch on the cross feed shaft, and positive geared connections from said clutch to said stop-engaging member. The clutch is normally held inoperative and adjustable automatic devices are provided for releasing the clutch'as the wheel approaches the finish of the cut. The stop-engaging mem ber then rotates until it engages the stop and positively holds the cross feed screw from further advance movement, this action being made possible by a friction connection between the drive shaft and the cross feed shaft.

A further feature of our invention relates to the provision of a device by which the cross feed may be readily adjusted for work of widely differing diameters, theadjustment being of an extremely simple nature.

Our invention further relates to certain arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

The preferred form of our invention is shown in the drawings, in which Figure 1 is a front elevation of a grinding machine with our improved cross feed mechanism embodied therein;

Fig. 2 is a sectional side elevation of the cross feed mechanism taken along the line 2-2 in Fig 1;

Fig. 3 is a front elevation of the shifting mechanism through which the operator conirols the changing and reversal of the fee Fig. 4 is.a top plan view of the feed changing and reversing handles, indicating. their several operative positions;

Fig. 5 is a sectional plan view taken along the line 55 in Fig. 3, and showing the cam and cam follower which control the slow and intermediate feeds, the parts being'set for slow feed;

Fig. 6 is a View similar to Fig. 5, but showing certain additional parts of the mechanism, set for intermediate feed;

Fig. 7 is a plan View of the cam and connections which control the fast feed of the grinding wheel, the parts being shown, however, as they appear during the slow feed of the wheel;

. Fig. 8 shows certain of the same parts in the position which they assume during the intermediate feed of the grinding wheel;

Fig. 9 shows the cam and cam follower .in the position to render the fast feed operative;

Fig. 10 is a vertical sectional elevation of the manually operated feed changing and reversing mechanism, taken along the line 1()-10 in Figs. 4 and 11;

Fig. 11 is a plan view of the reversing mechanism, partly in section, and taken along the line 1111'in Fig. 10;

Fig. 12 is a sectional side elevation of certain of the parts shown in Fig. 2, drawn on an enlarged scale;

Figs. 13 and 14 are face views of the two members of a clutch taken along the line 13-43 and 1-114 respectively in Fig. 12;

Fig. 15 is an enlarged side elevation, partly in section, of the device for automatically stopping the cross feed;

Fig. 16 is a front elevation of a portion of the device shown in Fig 15, and showing particularly the means for manually adjustin g the stop-engaging member Fig. 17 is a plan view of a portion of the mechanism through which the clutchis controlled which starts the automatic stopping device in operation;

Fig. 18 is a plan view of additional parts of the clutch control mechanism shown in Fig. 17;

Fig. 19 is a vertical sectional view of the parts shown in Fig. 18 taken substantially along the line 19-19 in said figure, and

Fig. 20 is a partial detail sectional view of the clutch-actuating sleeve.

Referring to the. drawings, we have shown our improved cross feeding mechanism as applied to a cylindrical grinding machine of a common type having a frame 10 upon which a work supporting table 11 is longitudinally movable. Work driving heads 12 are longitudinally adjustable upon the table 11 and suitable provision is made for rotating the work K (Fig. 2) supported thereby. These parts constitute no part of our present invention, and may be of any usual type.

The grinding wheel W is mounted on a wheel shaft 13 rotatable in bearings 14 and 15 in a cross feed carriage 16 slidable on suitable ways, not shown, formed on the rear portion of the frame 10. The grinding wheel may be driven by a belt 17 running on a driving pulley 18 secured to the shaft 13, or other suitable driving mechanism maybe utilized. i

The wheel carriage 16 (Fig. 2) is provided with a depending portion..19' to which is secured a half nut .20 which coiiperates with a cross screw 21 formed on a cross feed shaft 22 rotatable in a bearing 23 in the frame 10 and a bearing 24 in a frame member 10. A weight 25 is attached 'by,

a cord or chain 26 to the wheel carriage 16, normally drawing the carriageto the rear and taking up all backlash between the nut 20 and the feed screw 21.

A gear 27 (Fig. 12) is loosely mounted upon a sleeve 28 keyed to the shaft 22 and having an outwardly projecting flange 29 to which a ring 30 of friction material is secured. The gear 27 is pressed against the friction surface or ring 30 by an outer sleeve 31 keyed to the sleeve 28, but slidable thereon and having a flange 32 with a friction ring 33 engaging the side of the. gear 27 opposite to that engaged by the ring 30.

A spring 34 encircles the sleeve 28,between the end of the sleeve 31 and a. collar 35, said spring being effective to force the friction surfaces into driving en agement with the sides of the gear 27. T lie collar 35 is threaded upon the sleeve 28 and may be longitudinally adjusted thereon to vary the pressure of the'spring 34.

The gear 27 meshes with a gear 36 rotatable on a short shaft 37 fixed in a bracket I 38 on the frame member 10 The gear 36 meshes with a wide-faced pinion 40 formed on a clutch sleeve 41 loose on an intermediate shaft 42 and provided with clutch teeth upon each end thereof. The sleeve 41 is slidable on the shaft 42-by means of a yoke 43 (Fig. 7) which ismanually controlled by devices to be hereinafter described. The teeth 44 at the rear end of the sleeve 41 are adapted to engage similar clutch teeth 45 formed on a flanged collar 46 keyed to the intermediate shaft 42.

I The shaft 42'is rotatably mountedin bearings 47 and 48 in the frame member 10 and at its forward end is provided with a bevel gear 50 meshing continuously with corresponding bevel gears 51 and 52 (Fig. 11) each freely rotatable upon a clutch shaft 53 extending longitudinally of the machine and rotatable in bearings 54 and 55 (Fig. 11) and 56 (Fig. 3).

The shaft 53 is in alinement with a driving shaft 57 supported in fixed bearings 58 (Fig. 3) and 59 (Fig. 1). A cone pulley 60 may be secured to the driving shaft 57 and a belt shifting block 61 (Fig. 1) maybe slidably mounted upon the frame 10 for shifting a driving belt upon the cone pulley '60; The feeds of the entire cross' feed shaft 53. The driving shaft 57 is provided at its left-hand end, as viewed in Fig. 3, with a clutch collar 62 positioned for engagement with the teeth 63 of a slidable clutch collar 64 keyed to the clutch shaft 53. The

'collar 64 is controlled by a yoke 65 and other mechanism to be described. When the collar 64 is moved to its right-hand position.

with its teeth 63 engaging the clutch collar 62, there is a direct drive from the shaft 57 to the shaft 53, this arrangement giving the intermediate feed shown in Fig. 6, or the fast feed.

A pinion 66 (Fig. 3).is fixed to the shaft 57 and engages a gear 67 on a-shaft 68 and153 are connectedthrough the compound gears 66, 67, 70 and 71, and the slow or fine feed of the wheel carriage is thus secured.

The yoke 65 which determines the position of-the clutch 64 is mounted upon a rod 74 (Fig. 3) slidable in a bearing 75 and having secured to its opposite end a cam follower 76 (Fig. 6) embracing a cam 77 fixed to the lower end of an upright shaft 78 (Fig. 10) rotatable in a sleeve 79 which in turn is ro tatably mounted in fixed bearings 80 and 81 (F 1g.

A feed control handle'82 is keyed to the upper end of the. shaft 78 and the hub of the handle 82 is provided-with three notches 83 positioned for engagement by a spring plunger 84 mounted in a fixed support 85, the

plunger 84 serving to hold the handle 82 yieldingly in three different positions. When the handle is in the position indicated in full lines in Fig. 4 and marked Slow the posi- When the handle 82 is moved from the position marked Slow in Fig. 4 to that marked Intermediate the cam follower and. cam assume the relative positions shown in Fig. 6, thereby causing the clutch 64 to engage the clutch collar 62 and providing a direct drive at a higher speed from the shaft 57 to the shaft 53. y In order to complete the description of the means by which the several rates of feed are secured, it is necessary to further explain the driving connection between the 'widefaced pinion 40 and the intermediate shaft 42 previously described.

As stated; the clutch collar 41 (Fig. 12) is provided at its rear endwith clutch teeth 44 adapted for engagement with clutch teeth 45 on-a collar 46 fixed to the shaft 42. The clutch collar 41 is also provided with clutch teeth at its forward en 'l-adapted for engagement with corresponding teeth upon the hub 90 of an internal gear 91 freely rotatable about the axis of the shaft 42. An internal ring gear 92 is fixed in the frame member 10 concentric with the shaft 42 and adjcent to the side of the internal gear 91. A double pinion 93 is rotatably mounted upon an eccentric sleeve 94 fixed to the shaft 42 and rotatable therewith. The rotation of the shaft 42 and the eccentric sleeve 94 causes the pinion 93 to roll around on the inside of the internal gears 91 and 92. As the internal gears 91 and 92 differ by one or two teeth only, a differential effect is secured which results in a very slow continuous rotation of the gear 91.

Accordingly, for slow and intermediate feeds .the clutch collar 41 is moved into engagement with the hub 90 of the gear 91, such engagement resulting in relatively slow rotation of the gears 36 and 27. For fast feed, the clutch collar 41 is moved rearward into direct engagement with the shaft 42 and the differential-gearing becomes inoperative.

Such movements of the clutch collar 41 are secured through additional connections from the vertical shaft 78 previously mentioned. These connections include a cam 95 (Fig. 1.0) preferably integral with thecam 77, and keyed to the vertical shaft 78. The cam 95 cooperates with a cam follower 96 (Fig. 7) mounted on a rod 97 slidable at right angles to the rod 74 previously described, and having the clutch yoke 43 secured to its rear end.

- The relative positions of the cam 95 and cam follower 96 corresponding to the different positions of the handle 82 are clearly shown in Figs. 7, 8 and 9. In Figs. 7 and 8, corresponding to the slow and intermediate positions of the handle, it will be seen that the camfollower 96 engages concentric portions of the cam 95 and that in each position the cam follower. 96 and rod 97 are held in their extreme forward position, thus cans ingthe clutch sleeve 41 to engage the hub 90 of the internal gear 91, as shown in Fig. 7 ,and providing a differential reduction of speed between the shaft 42 and the pinion 40.

WVhen, however, the handle 82 is shifted from the intermediate to the fast position shown in Fig. 4, the cam follower 96, rod 97, and yoke 43 are moved rearwardly as shown in Fig. 9, and the clutch teeth 44 and 45 are engaged to give a direct drive between the shaft 42 and the pinion 40.

It will be noted also that during this last movement of the handle 82 the cam follower 7 6 remains in contact with concentric portions of the cam 77 as the cam turns in the direction of the arrow a in Fig. 6. The cam follower 7 6 therefore remains stationary with the clutch collar 64 engaging the clutch collar 62 fixed to the shaft 57. At fast feed, therefore, we

rovide a direct drive from the driving s aft 57 to the clutch shaft 53, and also from the intermediate shaft 42 to the friction gear 27.

WVe will .now describe the means for changing the driving connections between the shaft 53 and the shaft 42 toreverse the feed. A clutch collar 100 (Fig. 11) is keyed to the shaft 53 and is slidable thereon under the control of a yoke 101 into positions in which it engages clutch teeth upon the bevel gear 51 or the bevel gear 52. The yoke 101 is mounted on a rod 102 slidable in fixed bearings 103 and 104 and piv'otally connected at one end to an arm 105 forming a part of a cam follower 106. mounted on a stud 107 (Fig. 10) fixed in the frame member 10. The cam follower 106 engages a cam 108 (Figs. 10 and 11) keyed to the lower end of the sleeve 79. The position of this cam is determined by a hand lever 109 (Figs. 3 and 4) keyed to the upper end of the sleeve 79 and placed just below the handle 82 previously described.

The cam 108 and co6perating parts are shown in Fig. 11 in the position in which the clutch collar 100engages the bevel gear 52, thus turning the gear 50 and shaft 42 in the direction of the arrow, 7; in Fig. 11,

and moving the wheel carriage backward away from the work. The corresponding position of the handle 109 is that shown in dotted lines in Fig. 4, and marked Back. If the handle 109 is moved to the dotted line position marked Neutral in Fig. 4, the clutch collar 100will be positioned half-way between the two bevelgears 51 and 52, and will be out of engagement with both gears, thus putting the cross feed out of operation.

-Movement of the handle 109 to the full line position in Fig. 4 marked Forward en'- gages the clutch collar 100 with the bevel gear 51, driving the shaft 42 in the direction opposite to the arrow 1) and feeding the wheel carriage forward toward thework.

The handle 109 is provided with notches 110 coiiperating with a spring plunger 111 shown in dotted lines in Fig. 3 and effective to hold the handle yieldingly in any one of its three positions.

The mechanism thus far described enablesus to feed the wheel carriage forward or backward at any one of three different feeds,

fast, intermediate or slow, and it also enables us to 'stop or reverse the feed, thefeed changing, reversing and stopping mechanism being under the manual control of the operator. i

We will'now describe the mechanism for automatically stopping the cross feed at a predetermined point. gear 120 (Figs. 2 and 12) is freely rotatable upon a sleeve 1% (Figs. 12 and 20) slidably mounted on the forward end of the cross feed shaft 22 and provided with ke -ways 122 adapted to receive keys 123 ig. 13) pinned in corresponding key-ways in the shaft 22. A spring 124 encircles the shaft 22 and is secured thereon by a nut 125 and washer 126.

and being adapted to engage corresponding teeth on a flanged collar 130 (Figs. 12 and 14) keyed to the shaft 22. The ring 129 and collar 130 thus constitutea clutch which can be engaged only in a'single position. A ring 132 (Figs. 12 and 13) is fastened by screws to the right-hand end of the sleeve 121 and thus provides means for causing the gear 120 to move to the left to disengage the clutch when the sleeve 121 is moved in that direction.

Pawls 133 (Fig. 12) are mounted in the key-ways of the sleeve 121 and are pivoted to said sleeve by pins 134. The outer ends of the pawls 133 engage a grooved collar 135 slidable upon the sleeve 121 and positioned by a yoke 136 controlled by mechanism to be described. Flat springs 137 are secured in the key-ways of the shaft 22 and normally force the pawls 133 outwardly into position to engage overhanging portions of the keys 123, when the collar 135 is moved to the left (in- Fig. 12) by device's to be described. When the parts are in this position the pawls prevent movement of the sleeve 121 by the spring 124 to the right and therefore prevent engagement of the clutch members 129 and 130. The gear 120 is under these conditions free to rotate upon the sleeve 121.. v

The gear 120 meshes with a pinion 140 (Fig. 15) rotatable upon a stud 141'fixed in the frame member 10. A gear 142 is secured to the pinion 140 and meshes with a pinion 143 mounted on an arm 144 .freely movable for a part of a revolution on the outer end of the stud 141. When the stopping device is inoperative the weight of the arm 144 moves it normally to a depending position below the stud 141. The arm 144 has a surface 145 (Fig. 16) adapted to engage a'stop 146 formed on the end. of an arm 147 rigidly secured to a fixed portion of the frame.

The pinion 143 is formed on the end of a stud 148 slidable in a sleeve 149 and having a key-way150 cobperatingwith a pinkey 151 mountedin the sleeve. whereby relative angular movement of the P1111011- and sleeve is prevented. The sleeve 149 is freely rotatable in a hub 152 formed on the end of the arm 144. On the front end of the sleeve 149 is clamped an arm 153 having a hub 154 formed on the end thereof within which is slidable a spring-pressed plunger 155. The rear end of the plunger 155 is reduced in size and is adapted to enter any one of a concentric series of. holes 156 formed in the enlarged outer end of the arm'144. By withdrawing the plunger 155 from the holes 156 the armv 153 ma be rotatedcarrying with it the pinion 14 thus moving the arm 144 and its engaging surface'145 around the periphery of the gear 142, The holes 156 in the arm 144 are so spaced that the movement of the plunger 155 from one hole to the next adjacent hole will correspond to an advance of the grinding wheel amounting to one eighth of a thousandth of an 1I1Cll, correspondlng to a reduction of one fourth of a thousandth in the diameter of the work.

A spring 156 encircles the stud 148 with-.

in the sleeve 149 and maintains the pinion 143 in position to engage the gear 142. The stud 148 is extended beyond the front end of the sleeve 149 and is provided with a handle 158by which the pinion may be withdrawn when it is desired to securea more rapid adjustment of the arm 144 relatively to the gear 142.

It will now be clear that the arm 144 with its engaging surface 145' is adjustable feed shaft 22, such engagement ofthe surface 145 with thestop 146 positively limits advance movement of the feed screw and consequently of thewheel carriage. After the parts 145 and 146 are thus engaged the gear 27 on the shaft 22 continues to rotate until the operator stops or reverses the feed, such rotation being permitted b the friction drive between the gear 2? and the shaft 22.

While we have thus provided a very accurate device for stoppmg the feed of the grinding wheel it will be evident that the movement of the gear 142 and stop-engaging member 144 is limited to a portion of one revolution, corresponding to a much smaller portion of a revolution of the shaft 22. It is therefore impossible to effect any considerable feed of the wheel carriage after the the clutch members 129 and 130, to the cross gear 142 is connected with the shaft 22.111

and we therefore provide meansfor automatically engagin the clutch members 129 and 130 when the orward feed of the grinding wheel is substantially completed. This en aging means will now be described.

he yoke 136 (Fig. 12) which controls the sliding collar 135 is formed on the end of a lever 160 (Fig. 3) loosely mounted upon the vertical shaft 78 and having an arm 161 extending on the opposite side of said shaft. In the end of the arm 161 there is yieldingly mounted a plunger 162 (Fig. 17) encircled by a spring 163. The plunger 162 is alined with a rod 164 (Figs. 17 and 18) slidable in fixed bearings 165, 166 and 167, and provided at its rear end with rack teeth 168 meshing with'a pinion 169 rotatable in a fixed bearing 170 (Fig. 19) and meshing in turn with a gear 171 rotatable in a fixed bearing 172 adjacent the bearin 170. A worm gear 173 is secured to a sha t 174 having a bearing within. the hub of the gear 171 and meshes with the feed screw 21. The

gears 171 and 173 are provided with co'o'perating friction surfaces which are forced yieldingly together by a spring 175, as clearly shown in Fig. 19.

With these connections it will be evident that therack rod 164 will be advanced in timed relation with the wheel carriage until it engages the plunger 163 in the arm 161. Contlnued forward movement of the rack rod moves the lever 160 and yoke 136 to shift the sliding collar 135 (Fig. 12) thereby moving the engaging portions of the.-

pawls 133 inward and permitting the spring 124 to force the clutch member 129 toward the clutch member 130, and to enter driving relation therewith as soon as the irregularly spaced teeth of the two clutch members are properly alined, which alinement can occurat one point only in a revolution of the shaft 22. Thereafter the gear 142 and arm 144 will move in unison with the shaft 22 until: the stop 146 is engaged, and thereby prevents further rotation of the shaft 22, and the cross feed screw 21.

The spring 163 is of sufficient power to overcome wlthout compression the resistance of the flat springs 137 which hold the pawls 133 in engagement with the keys 123. and the friction between the gears 171 and .173 is materially stronger than the spring 163, so that the relative adjustment of these gears cannot be changed by pressure transmitted through the spring.

When a change is made to work of a larger diameter, it is necessary to advance the rod 164 so that it will engage the plunger 162 correspondingly earlier. For this 7 pose we provide a hand rod 180 (Fig. 17') I shdable in a fixed bearing 181 on the frame member 10 and also slidable in a collar 182 secured tothe rod 164. The hand rod'180 .is provided with a knob 183 at its forward purend and with check nuts 184- at its rear end. By grasping the knob 183 the hand rod may be pulled forward, carrying with it the rack rod 164, such movement being possible by overcoming the friction between the gears 171 and 173. When the rod 164 has been positioned to engage the clutch members 129 and 130 at approximately the desired point the final adjustment of the stopping mechanism is obtained by adjusting the arm 144around the gear 142 by the index mechanism previously described. It will be noted that the hand rod 180 is freely slid- .rev'olution of the cross feed shaft 22.

'It will be. understood that other well known forms of friction connections can be substituted between the lever 161 and the worm gear 173, it being merely necessary to provide a friction device of some form strong enough to overcome the springs 163 and 137.

.in Fig. 4 causes the adjusting screw 191 to engage and move the arm 161, overcoming the resistance of the spring 163. The yoke 136 is thus moved to withdraw the collar 135, compressing the spring 124 (Fig. 12) and permitting-the pawls 133 to'engage the overhanging portions. of the keys 123, by

which engagement the clutch members 129 and 130 are held out of engagement.

. The collar 182 on the rack rod 164 is positioned to engage the rear end of the bearing 165 as soon as the rack rod has moved the lever 160 sufiiciently to release the pawls 133 andthus permit engagement of the clutch members 129 and 130.

Having described the operation of the several parts in connection "with the detailed description therepf, it is thought that an extended statement .of the operation of our invention is unnecessary. It will be seen that we have provided forfast, intermediate and slow feed of the wheel carriage andgalso for reversal offeed at any speed,

, termined rate which is adapted to the particular grinding wheel with which the machine is equipped. The stopping mechanism is so designed that it will operatewith extreme positiveness and accuracy and the devices by which this mechanism may be set are exceedingly simple in operation.

In the usual operation of the machine upon rough forgings or castings, it is expected that the operator will advance the wheel at the fast feed until the wheel engages the irregular projections upon the work. He will then shift to the-intermediate feed, at which feed the wheel will be advanced until it engages the solid stock of the forging or .casting. A shift is then made to slow feed for the normal grinding operation which continues until automatically thrown out by the stopping mechanism. The operator then reverses the feed by the lever 109 and also shifts the feed lever 82 so that he may withdraw the wheel at high speed. The feeding operation is thus fully automatic while at the same time it is always under the control of the operator.

If, after the feed has been automatically thrown out by the'stopping mechanism, it is found desirable to grind off a further small amount, the pin 155 on the micrometer feed adjustment may be drawn out against the action of its spring and moved back one or more notches as desired, thus rotating the pinion 143 to move the arm.

144 backward relative to the stop. The grinding wheel may then be automatically fed forward a further slight amount until the stop 146 is again engaged. It will be observed, however, that this fine adjustment of the feed can be utilized only while the clutch members 129 and 130 are engaged.

Having thus described ,our invention, it will be evident that changes and modifications can be made therein by those skilled inthe art withoutdeparting from the spirit and scope of ourinvention as set forth in the claims, and we do not' wish to be otherwise limited to the details-herein-disclosed, but what we claim is 1 1. A cross feed mechanism for grinding machines comprising a-Wheel carriage, a

cross feed, shaft having driving conru'action therewith, automatic means for rotating 'said feed shaft, and manually-operated devices effective to control said automatic means, said automatic means constitut ng the sole feeding means for said wheelcarriage, and

being operable by power only.

2. A cross feed mechanism for grinding machines comprising a wheel carriage, au-

tomatic mechanism for feeding said carriage toward and from the work atany one of a plurality of definitely related speeds,

I andrmeans under the control of the operator to selectively determine the speed and direction of feed, said automatic mechanism const tuting the sole feeding means for. said wheel carriage, and being operable by power shaft, means including gearing by which i the speed relation of said driving shaft to said intermediate shaft may be definitely changed, means including additional gearing by which the speed relation ofsaid intermediate shaft to said cross feed shaft may be definitely changed, and manually-oper-' ated devices for controlling said feed changing means.

- A cross feed mechanism for grinding machines having, in combination, a wheel carriage, a cross feed shaft having driving connection therewith, a driving shaft,speed changing gearingbetween said driving shaft and said cross feed shaft including a differential gear drive for slow feed, and means to selectively control said gearing manually.

6. Across feed mechanism for grinding machines having, in combination, a wheel carriage, a cross feed shaft having driving connection therewith, a driving shaft, speed changing gearing between said driving shaft and said cross feed shaft including a differential gear drive for slow and intermediate feed and a lirect gear drive for fast feed,

I and manual means to selectively control the gear drive'from said intermediate shaft to said cross feed shaft.- an additional differential gear drive between saidlatter shafts, and manual means effective to controlsaid drives and render the same selectively operative.

8. A cross feed mechanism for grinding "machines having, inflcombination, a wheel carriage, a cross feed shaftqhaving driving connection therewith, a stop, a stop engag ing member, connections between said mem operation, and automatic means to release said clutch for engagement thereof as the wheel approaches the finish of its out.

10. A cross feed mechanism for grinding machines having, in combination, a wheel carriage, a cross feed shaft having driving connection therewith, feeding mechanism including a friction drive for said cross feed shaft, a stop, a stop engaging member, and

means to positively connect said member to said cross feed shaft, said friction drive permitting the stopping of said shaft upon engagement of said member and stop while said. feeding mechanism continues in motion.

11. A cross feed mechanism for grinding machines comprising a wheel carriage, a cross feed screw for said carriage, afriction drive for said feed screw, a rotatable stopping member, a fixed stop positioned for engagement bysaid member, and automatically controlled means for positively connecting said stopping member with said feed screw, said stopping member upon engagement with. said stop after apartial revolution of said member positively locking the feed screw against further advance movement.

12. A cross feed mechanism for grinding machines having, in combination, a wheel carriage, a cross feed shaft having driving connection. therewith, a fixed stop, a rotatable stop engaging member limited in movement by said stop to a portion of a revolution, aconnection between said member and said cross feed shaft including aclutch, and means to engage said clutch at one point only in a revolution of the cross feed shaft, said shaft being thereafter positively stopfid after a partial revolution of said mom 1'.

' 13. A cross feed'mechanism for'grinding machines having, in'eombination, a wheel carriage, a crow feed shaft having driving connection. therewith, a fixed stop, a movable stop engaging member, aconneetion between said member and saidcross'feed shaft including reduction gearing--and a clutch capable of engagement at one point only of 'a revolution,'and automatic means to engage said clutch as the grinding wheel approaches the of its cut'.

14. A cross feed mechanism for grinding machines having, in combination, a wheel carriage, a cross feed shaft having driving connection therewith, a stop, a stop engaging member, connections between said member and said cross feed shaft including a clutch, and means to engage said clutch automatically as the wheel approaches the finish of its out, said means including a clutch-engaging spring, devices normally rendering said spring inoperative, and means to move said devices to release said spring. I

15. A cross feed mechanism for'grinding machines having, in combination, a wheel carriage, a cross feed shaft having driving connection therewith, a stop, a stop engag- -'1ng member, connectlons between said memher and said cross feed shaft including a clutch, and means to engage said clutch automatically as the wheel approaches the finish of its out, said means including a clutchengaging spring, pawls normally rendering said spring inoperative, and means to move said pawls to release said spring, said latter means including a rack rod, a'pinion engagng said rod, and a friction drive from said cross feed shaft to said pinion. D

16. A cross feed mechanism for grinding machines having, in combination, a wheel carnage, a cross feed shaft havlng driving connection therewith, a stop, a stop engagmember', connections between said memher and said cross feed shaft including a clutch, and automatic means to engage said clutch as the wheel approaches the finish of its cut, said means including a yielding element permitting manual disengagement of said clutch without changing the adjustment of said automatic engaging device.

. 17. A cross feed mechanism for grinding machines having, in combination, a wheel carriage, a cross feed shaft having driving connection therewith, a stop, a stop engaging member, connections between said member and said cross feed shaft including a clutch, and automatic means to engage said clutch as the wheel approaches the finish of its out, said meansincluding a friction connection whereby adj u'stment may be readily made, and a spring plunger permitting out disturbing theadjustment of said friction connection.

18. A cross feed mechanism for grinding machines having, in combination, a 'wheel -manualdisengagement of said clutch withcarriage, a cross feed shaft having driving I connection therewith, a stop, a movable stop engaging member, -,a connection between said member and said cross feed shaft ineluding a clutch, means -to hold said clutch clutch simultaneously with the reversal of the feed.

19. A cross feed mechanism for grinding machines having, in combination, a wheel carriage, a cross feedshaft having driving connection therewith, a'fixed stop, a movable stop engaging member, a connection between said member and said cross feed shaft including a clutch, means to hold said clutch normally out of operation, automatic means to release said clutch for engagement thereof as the wheel approaches the finish of its cut, said means comprising a friction-driven actuating member, and manual means for overcoming the friction and advancing said member to adjust said releasing means for work of greater diameter.

20. In a grinding machine, a cross feed mechanism, a driving shaft, two separate devices for establishing predetermined speed relations between said shaft and mechanism, and a single hand-operated cam shaft controllin said two devices.

21. n a grinding machine, a cross mechanism including two separate speed changing devices, a hand-operated shaft, and two separate cams on said shaft controlling said two speed changing devices, each cam having a dwell portion and being inoperative while the other cam is operative,

whereby one speed changing'device will remain unchanged in condition while the other device is being thrown into or out of operation.

22. In a grinding machine, a cross feed mechanism, a driving shaft, two separate devices for establishing predetermined speed relations between said shaft and mechanism, a hand-operated cam shaft controlling said two devices, a reversing mechanism, and a second hand-operated element concentric with said cam shaft for controlling said reversin mechanism.

23. cross feed mechanism for grinding machines comprising a wheel carriage, a grinding wheel thereon, a support to position the work adjacent said wheel for grinding, and exclusively automatically actuated means to move said carriage and work relative to each other to feed the wheel into the work during a grinding operation.

24. A cross feed mechanism for grindin machines comprising a wheel carriage and a rinding wheel thereon, a support to SltlOIl the work adjacent said wheel, m anism to move said carriage and work relatively toward and from each other, a power shaft,--and driving connections between said shaft and said mechanism, said mechanism, said shaft and said connections constituting the sole feeding means and producing a continuous mechanical feeding action.

25. A- cross feed mechanism for machines comprising a wheel carriage, a

g i g heel thereon, a support t p051- feed I stop the carriage at .a and means to adjust t e relative positions tion the work adjacent the wheel,mechanically operated means to feed said carriage relative to the work at a uniform, constant rate to insure even grinding, and manually operated means effective to control the automatic means to change the rate without uously driven from said shaft to move said carriage and Work relative to each other to feed the wheel into the work at a constant, uniform rate of cutting during a grinding operation, and manually operated means for controlling the rate and direction of the cross feed operation but preventing manual feeding at will to produce a non-uniform grinding action.

27. A cross feed mechanism for grinding machines having, in combination, a wheel carriage, a cross feed shaft having driving connection therewith to move the carriage, driving, mechanism, two frictionally engaged relatively adjustable members actuated by said driving mechanism, and means controlled by one of said members to stop the carriage at a predetermined point depending on the adjusted relative positions of said members.

28. A cross feed mechanism for grindin machines having, in combination, a whee carriage, a cross feed shaft having drivingconnection therewith to move the carriage, a friction drive actuated by saidshaft, means controlled by said friction drive to redetermined point,

of the members of said drive to .vary the point of stoppage.

29. A cross'feed mechanism for grinding machines comprising a wheel carriage, a grinding wheel rotatably mounted thereon, a support to position the work adjacent said wheel, and automatically actuated means to move said carriage and work relative to each other whereb the work and wheel are moved toward each other during a grinding operation at a continuous uniform and predetermined rate.

30. A cross feed mechanism for grinding machines having, in combination, a wheel carriage, a cross feed shaft having driving 4 connection therewith, a stop, a stop engaging member, connections between said member and said cross feed shaft'and automatic means effective as the' wheel approaches the finish of its out to engage said 'connectlons and thereby move said member against said tomatica 1y as carriage, a cross feed shaft having driving connection therewith, a fixed stop, a stop engag'in member, and means operating au- 7 the grinding Wheel ap the movement of said member relative to the movement of said shaft.

In testimony whereof We have hereunto aflixed our signatures.

CHARLES H. NORTON. ALBERT TURNER. JOSEPH S. WILCOX, JR.

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