US1432093A - Grinding machine - Google Patents

Description

' W. TAYLOR` GRINDING`IVIACHINE. APPLlcAnoN FILED o`c.2s.1916.

19mm @en W9 31922,

9 SHEETS-SHEET l.

INVENTOR.

- v ATTONEY W.'TAYL0R.

GRINDING MACHINE.

APPLICATION FILED OCT. 2S, I9I6.

Patented @on 117,11922.v

9 SHEETS-SHED 2.

. www S @SS INNTOR.

W. N m T T A W. TAYLOR.

GHINDING MACHINE.

APPLICATION FILED ocT. 2a. 1916.

ILP-muted ome, 1179 11922.

9 SHEETS-SHEET 3.

NVENTOR. M ZV AoRNEY W. TAYLOR.

GRINDING MACHINE.

APPLICATION man ocT. 2a. 1916.

Mmmm

I N TOR.

W. TAYLUR.

GRINDING MACHINE.

APPLICATION FILED o'cT. 2s, I9Ie.

W. TAYLOR.

GRINDING MACHINE. I APIPLlcATloN FILED ocr. 2a, 1916.

Hamm Pante Oct. 117, E922.,

9 SHEETS-SHEET 6.` I

INVENTOR.

W.TAYLOR.

GRINDING MACHINE.

APPLICATION FILED ocT. 2a. 1916.

IPM/@ma @GI 17,1922.,

v9 SHEETS-SHEET I.

A/ ATTORNEY.

W. TAYLOR.

GRINDING MACHINE.

APPLICATION man ocr. 28. 191e.

Mmmm.

9 SHEETS-SHEET 8.

@ATTORNEY Patented 00E. i7, E922.

W- TAYLOR.

GRINDING MAcHmE.

. APPLICATION FILED OCT. 28| 1915. LQSQJQS. )Patml @et 'l'y 1922.,

9 SHEETS-sain s.

' I INVENTOR. www 7 BVM I7 4.5 ATTORNEY.

Y that at any time one or more of the spmdles Patented @et il?, 1922.

narran stares WXLLEAM TAYLR, 0F LEECESTER, ENGLAND.

GE'NDING MACHINE.

Application filed october 28., wit. Serial No. M.

To all whom t may concern:

Be it known that I, WILLIAM Terrien, a citizen of Great Britain, residing at llfelceslter, in the county of Leicestershire, England,

have invented certain new and useful lmprovements in Grinding Machines, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This invention relates to machines for performing grinding and similar operations, and contemplates particularly the provision of apparatus by 'which a number of similar objects may be operated upon rapidly, and preferably, as far as possible automatically. Certain features of the invention are applicable to grinding and like machinery generally, but the invention is intended chiey to provide apparatus for grinding lenses or other objects of glass and it is especially adapted to the grinding of the surfaces of lenses.

Among the objects of the invention are to provide apparatus of the character referred to, which will operate in a rapid and eco-l nomical manner, a plurality of operations preferably being carried on simultaneously; to provide apparatus which will require little attention on the partof the operator and which will be largely automatic in its operation; to provide mechanism which will grind lens surfaces with accuracy, Without depending upon the skill of the operator to produce such results; and to provide an apparatus'of such character that blanks which are not of uniform dimensions will be so operated upon as to`produce a uniform product.

A more specific object of this invention is to provide a glass dise and lens grinding machine in which a number-of work carrying spindles are mounted in a turret which, for the purpose of positioning and feeding the work to suitable power driven abrasive cutting or grinding tools, is advanced and retracted with respect to the tools and intermittently rotated to bring the work carrying spindles successively into proper operative position with respect to the tools, the extent of each successive rotation bein such will be retained in a position wherein a hnished disc or lens can be removed from its holder on a spindle and a fresh glass blank inserted. rlhus these operations can be performed while the grinding processes on -other lenses are proceeding, and also where means are provided for performing more than one operation on a lens or blank, the varlous operations can be carried on simultaneously on blanks in di'erent stages of completion. Saving of time and the maxi mum eihciency Iin the use of the machine are thus attained.

rllhe invention will be described as applied to a machine whose turret is fitted with, for eaample, three work spindles, and with the a1d of` the accompanying drawings in which z- Fig. 1 is a plan view of a glass disc grindlng machine embodying the invention;

Fig. 2 is a front elevation of the machine;

F igs 3 and d are side elevations viewed fromgthe right and left hand respectively, some portions being omitted;

Figs. 5 and 6 are elevations, viewed from the right and left hand respectively, of the turret and mechanism for operating it on a larger scale than Figs. 1 to d;

Fig. 6 is a front elevation of the turret rotatin mechanism sectioned on a vertical plane t rough the axis of the turret shaft 1b, and F igs. 6b and 6c are vertical sections taken on the lines Vlbb and VF--Vllc of Fig. 6 respectively; Figs. 7 and 8 are respectively right side and rear elevations of mechanism for the slow feed motion of the turret, Fig. 7 show- 8a a rear elevation sectioned on a vertical plane through the axis of the shaft 6a, of the slow feed mechanism, Fig. 7 showing the clutch pawl disengaged to permit the 'operation of the fast feed; Figs. 9 and 10 are details showing a work spindle mounted in the turret;-

Fig. 11 is a detail sectional view taken on line .Xl-Xl on Fig. l and Figs 12 and 13 are detailed views showing the chuck releasing means, Fig. 12 being a horizontal section on the line Xlll-Xlli of Fig. 13, and Fi. 13 a vertical section on the line Xlll- 'l of Fig. 12.

lin the drawings, 1 is the turret which is mounted on a shaft rotatable in a longitudinal. slide 2, and carries at three equidistant points in its Aface work s indles 3, 3a and 3b similarly constructed an adapted to be rothe disc which has been roughed thereby to-v tated by some suitable means. The axes of the work spindles, as shown, are parallel to and at equal distances from the axis of rotation of the turret. The spindles carry at their outer ends, in suitable chucks 3, (Figs. 3 and 9) the discs of glass 24 which 4are to be formed by grinding into lenses.

ln the positions of these spindles as shown in Figs. l and 2, the disc carried by the spindle 3b is ready to be operated on by an adjustably mounted abrasive Wheel 4l, which is here regarded as a roughing wheel and may be vset either to grind the centre of the disc so as to make it concave or to grind the outer edge of the disc so as to make its face roughly convex or bevelled.

rll`he disc carried by the spindle 3 is lin i position to be operated on by the adjustably mounted wheel 5, which is of cup form and provided with an annular grinding edge, and may be applied to grindon the face of the glass disc a spherical curve either convex or concave, and whose radius may be varied either by varying the diameter of the abrasive wheel or the angle at which its axis is inclined to the axis of the work spindle 3 or by varying both of these factors.

While these wheels are operating on discs in spindles 3 and 3b, the spindle 3a is in a position where the operator may remove the finished work and replace it by a fresh disc.

In order to advance thev turret and its work spindles toward the abrasive wheels to effect the grinding, the slide 2 is reciprocated at suitable times and speeds by a crank 6, (see Fig. l) and at each reciprocation the turret, iny the case of the machine herein shown, is rotated `on its shaft one third of a turn so as to bring the spindle 3 with the finished glass into the position 3, to carry the fresh disc to the .roughing wheel it, and

the finishing wheel 5.

rl`he machine comprises a bed 7 on legs 7, 7b, and 7, and carrying a pan 7d with upturned edges to catch liquid and detritus from the abrasive wheels, and having a weir 7V, (Figure l1) to retain the silt precipitated from the liquid and an outlet pipe 7x todrain the liquid away.

The bed is adapted to carry, as shown in Fig. 1, the various mechanisms now to be described for operating the work spindles, rotating the turret, advancing and withdrawing the turret and,work spindles to and from the abrasive Wheels at suitable speeds, and for setting and driving the roughing and finishing Wheels 4, 5.

Turret and work' spindles.

lasaoea Fach work spindle is hollow Land is rotatably mounted in bushes 3c and 3' 9 and l0), of which thefirst is convenlent y fixed by being-forced into the hole in the turret, and the other removably clamped by means of a screw a-nd nut 3" which is arranged to close a split part of the hub oontaining the bush. To lubricate the spindle bearings from Within, and carry the lubricant outward so as to prevent access of dirt, grease is supplied to the annular space between the bushes through radial holes 3f, and a chamber in the turret bore from alubricator, not shown, communicating with that chamber and placed so as to be accessi. ble from the back of the turret.

Each of the spindles 3, 3a and 3b is adapted to receive changeable split chucks 3h of the kind well known in connection with Watch machinery and lathes, these chucks being suitably bored and recessed according to the diameter and thickness of the glass discs to be held.

The chuck 3h is drawn into the conical mouth of the spindle 3 so as to grip the glass 90 disc, by the draw-in rspindle 3i which has fixed upon it a driving pulley 3j, in a chamber 3k of which is a compression spring 3l adapted to close the chuck by pulling out the draw-in spindle, which is attached to it in the well known manner bybeing screwed into the chuck at 3m. The strength of this spring is such that while it holds the glass securely in the chuck it does not crush it.

. In order to secure uniformityv in the thickness of the lenses, the overall lengths of the three spindles 31 and of the chucks 3h are made quite uniform, and during the grinding operationthe outer end of the draw-in spindle 3i is thrust by the corresponding abrasive wheel against an abutment, that is hereafter mentioned, and fixed onthe machine.

In order that a spindle 3 may be free endwise for this purpose while being unable to stray unduly, a retaining collar 3 (see Fig. 9) is fastened to the spindle by a screw 3, and a light compression spring 3P is provided to thrust against the collar 3, and a loose sleeve 3, so as to move the spindles 115 and 3i toward the fixed abutment aforesaid, and a suitable but limited end shake in the bearings is permitted by the space 3between the collar and the bush 3d.

Turret mounting.

'in bau uw he housing 2 rests in the ways by gravity alone. y

Keyed to the shaft 1b and clamped thereon by the nut 1g, Fig. 2, so as to take end shake out ofthe shaft bearings, is a three armed spider l, (see Fig. 6), whose function is to hold the turret against rotation in its three equidistant operative positions; and in order to provide for slight adjustment rotationally in such positions of the turret, the spider 1h is keyed to the shaft 1", as is shown especially in Fig. 6, by means of two thrust rods 1 and 11 which are adapted to thrust against diametrically disposed faces 1k and 1l of recesses formed in the shaft 1", the thrust rods being acted upon by screws 1m and 1, so that by unscrewing one and screwing up the other the spider 1h may be slightly rotated or securely held against rotation on the shaft 1b.

rlihe arms of the spider which position the turret are preferably formed as pieces of steel 1P, 1q and 1, hardened and ground, and held by bolts and nuts l, 1t and 1, in equidistant radial slots formed in the spider drum 1h.

The spider arms are adapted to engage in turn an abutment fixed on the bed 7, and which will be more particularly described hereafter.

Turret traverse mechanism.

'ln order to move the turrent 1 with its work spindles and work to and from the abrasive wheels, the housing 2 is made to reciprocate in its supporting ways 7". by

l' means of a crank 6, Figs. 1 and 2, which is carried at one end of a crank shaft 6a housed in'bearings 6b and 6c in a suitable frame 6d bolted upon 'the vcross member of the bed 7.

rllhe crank 6 has a pin 6e which actuates a block 6, Fig. 1, sliding between the sides of a vertical slot 6g in the rear side of thehousing 2. By this means rotation of the crank shaft 6a communicates a reciprocating motion to the sliding housing 2 and the turret associated with it.

Fast and slow feeds.

ishes (and the work dwells for a time) as the crank respectively approaches and passes its dead centre.

ln order to save time in operation it is desirable to provide means whereby this reciprocating motion ofthe turret while taking place at a suitable but variable slow speed during the actual grinding operation,

should at other times be as fast as is practicable to effect the withdrawal and exchange in position of the work spindles.

For rotating the crank shaft at variablespeeds for these purposes the following mechanism is used, and for convenience is"l formed as a self-contained unit on the frame 6d. lt is shown in elevation and part section in Figs. 1 and 5.

Upon a stud` 6h -fixed in the side of the frame 6d and .confined by a collar 6i is mounted a pulley 6j which has attached to it a sleeve 6kand a pinion 6.

The pulley is driven at a constant speed by a belt from any convenient source of power, and the pinion 6 drives a toothed wheel 6m keyed to a worm shaft 6 housed in bearings in the frame 6d and carrying between the bearings a worm 6, Fig. 5, which drives a worm wheel 6P, rotatably mounted on a hub 61 keyed to the crank shaft 6a and having a flange 6r against which the worm wheel 6P is thrust by a star shaped spring 6S through the medium of a plate 6t slidably keyed to the hub 61' and bearing against the other side of the worm wheel 611`so as to attach it frictionally to the crank shaft 6a. To enhance this friction the worm wheel 6lD may be faced with a ferodo ring 6 riveted to it.-

By these means the crank shaft 6 tends tobe driven at a fixed speed, and this speed is such as to withdraw the turret and the work spindles from the abrasive wheelsafter the completion of each grinding operation, and to return the same for the next operation as fast as is practicable in order to save time.

As the fresh discs vof glass then approach the abrasive wheels it is necessary to retard the speed of rotation of the crank shaft, and for this purpose a second worm wheel 8, Fig. 5, is rotatably mounted onthe crank shaft 6, and is driven by aworm 8b on a worm shaft 8c housed in bearings in the frame 61 and driven at speeds which may be varied by means of a band 8d and stepped cone pulleys 8e and 6y fixed to the shafts 8c and 6n respectively. (See Fig. 1.)

Suitable means are provided for tensioning the band 8d and those shown in the drawings comprise a weighted pulley 8f, Fig. 4, suspended by the band, which can be carried round a fixed idler pulley 8g to keep it clear of other mechanism.

The Worm' wheel 8a has a hub 8h, (Figs. 7 7a, .8, 8%) which is free to rotate both on 25 varied by sliding more or less over it a seg.-

Normally,y however, the pawl 8' is held.`

from so engaging the hub 8h by its tail end 8p lying withln an encircling casing 8, as

shown in Fig. 7, adjustably clamped by a bolt and its split hub 8r to a projecting part j .of one of the bearings of, and concentrie with, the crank shaft 6a in the frame 6d (Figs. l, 7, 8, 7, 81). ,Y

That part of the casing 8q which extends,

` as Fig. 8 shows, only half way across the tail end 8p of the pawl 8', has a gash or slot formed in it between the points 8 and 8t (Figs. 7, 7). i

The etl'ective'length of this gash mayA be ment 8 which is adjustably clamped to the casing 8l by the bolt 8" and the hand nut Vte 8w (Figs. 8, 11).

The worm wheel 6 and the crank shaft 6, with the clutch casing 85, normally rotate in the direction of the arrow in Fig. 7 and at the speed determined by the friction wheel 6 until the time when the crank has caused the workspindles to approach near to the abrasive wheels.

At such points, which may be varied by lsetting the segment 8 aforesaid, the end 8D of the clutch pawl 81 escapes from the end of the segment 8, passing into the above mentioned gash-or slot whereupon its cam part 8 engages the hub 8h of the worm' wheel 8, and, causing the friction wheel 6P to slip, compels the crank shaft to assume the slower rate of rotation of the worm wheel 8.

This slow rotation, and consequent lslow advancement of the work to the abrasive wheels, continues during the grinding operation until the `crank pin 6, having reached its centre andhaving advanced the work as far'as possible is ready to withdraw it. At this point the end SlT-of ytheclutch pawl 8*,

as is shown dotted in Fig. 7 encounters the.

end lof gash i8 in the casing 8q and the pawl is turned so that' the clutch is disengaged and f the crank shaft set free-to assume the higher rate of rotation proper to its friction driven worm wheel 6P. y

When lass discs of various'` thicknesses are to be ormed into similar lenses, the segment 8 must be set to suit the thickest discs to avoid crushing them or the abrasive wheels, and for such cases to avoid, the waste of time which would occur' when a thin glass is put into the machine .l 'make provision for rotating the crankshaft man ually by means of the pulley 8, Fi 7, attached to the end of the worm s aft 8, which.` may be turned bya weighted band 8y passing through orcelain eyes 7t and 7g, Fig. 5, in the bed and havlng a handle 8 (Fig. 2) by which the band maybe pulled so as to rotate the pulley 8, and thereby accelerate the motion of 'the crank shaft 6a. Upon releasing the handle 8z the band 85 slips over the pulley 8x without rotating it backwards.

In order to arrest withdrawal movement of the turret after each grinding operation, until lsuch time as the operator has-changed the work in the idle workspindle, l fix in the clutch casing 8j a radially projecting* pin 9. Fig. l, 5, 7 and 8, having a face 9, adapted to engage the end of a bar 9, rotjatab'ly joirnaled in the frame 6 and lin a bracket 9d at the vfront of the bed 7. Part of the rear end 'of the bar is cut away so that in the. position of rotation as shown in Fig. 5, the pin 9 can rotate past it, but when the bar is turned through a suitable angle of, for instance, about 30 degrees, the pin 9 is obstructed by it so as to prevent rotation of the crank at the time when .'the grinding operation is just completed.

ln order to limit the rotation of the bar 9c so that it may be placed in either of these two 'operative positions, and at the same time to prevent its withdrawal from its bearings, a disc shaped key 9h (Fig. 5) is fixed in the frame 6, and enters a slot cut in one side of the bar 9c of such size and position as to limit the rotation of the bar as aforesaid. The outer end of bar 9 has rotatabl upon it a handle 9 (Figs. 2 and 5)v confined by a'key 9t which engages a slot 9g in the side of the bar 9 in such a way that while' confined against endwise motion on the bar the handle 9e can rotate upon it through an an le of about 7() degrees, A

hen the handle 9a is lifted to the 4position shown in Fig. 5, its key 9t rotates the bar 9 until it encounters the key 9, and in this positionthe pin 9 is released so as to permit rotation of the crank/and withdrawal f j ofthe turret. l D

Projecting fromthe' front of the sliding housing 2 is a "in-25510 placed that upon,A H

', into the position shoiffvn in"F ig. 2, and in so;

-such withdrawa Aof the turret it encounters-'12@ falling' turns the bar. 99".;'into the position..

where itobstructs the passa of the pin ist.

9 and 'further .withdrawal-ot turret.

By these means, theopemtogfwho my b f attendin several machmesfis assured that the with awal movement of theturret will be arrested until he has changed the work 11:39

menaces and lifted the handle 9@ to its upright position.

Turret rotating' mea/na.

exterior upon which a collar lOlJ is rotatably' mounted (Figs. 2, 6, 6, 6", 6) and the nut and collar are confined against end shake by being lodged between the faces of a gash l0c in a bracket 10d fastened to the bed 7 (Fi 6B).

The bracket 10d has a cap lOa removably attached to confine the shaft 1* against littingor permit of its removal.

he nut l0a has cut in its periphery a number of longitudinal equidistant slots or teeth l0t adapted to engage a spring pawl y 10g pivoted at l0l1 to the collar 10b, so as to permit rotation of the nut Within the collar in one direction only (Figs. 6, 6, 6b).

The number of teeth l0i may e ual, or be a multiple of, the number o? work spindles in the turret.

'lhe collar 10b has in its periphery a notch 10i adapted to engage a spring urged pawl l1 pivoted to a shaft llajournalled in the base of the bracket 10d. (Figs. 6, 6b.)

Upon this shaft is a crank arm 1lb having a bevelled end llc adapted to engage, and be depressed by, a corresponding bevel on the end of each of the spider arms 1P, l1,1r when the spider is positioned for a grinding operation by encounterinr ari-abutment plate 11d, preferably of hardened steel; attached to the bed 7 (Figs. 6a, 6).

ln this operative position, one of the arms of the spider, for instance, arm l, is held against the abutment 11d by a spring urged bevelled lock piece l1", engaging the bevelled face lZ of the spider arm, 'the lock piece being attached to an arm llf pivoted at llg to a shaft journalled in the bracket iod (rig. e).

Cross pins 11h and lli fixed in the shafts 1la and l1g respectively have between them a helical tension spring lli, which tends to urge the pawl l1 and the lock piece 11i rotationally as aforesaid (Fig. 6b).

The action of this mechanism is as follows During each grinding operation, the tur'- ret with its work spindles is positioned rotationally by one of the spider arms, lr in the drawings, resting against the abutment 1ld under the action of the spring urged lock piece l1, which exerts a wedging action against the bevelled surface lz (Figs 6", 6c).

Upon the completion of the grinding operation, the pin 9 being treed from obstruction by the shalt 9, the crank withdraws the turret by sliding its housing 2 lengthwise, and during the iirst period of such withdrawal while such rotation of the turret is prevented by the abutment 1ldl the screw l0 moves endwise within the'nut, 10, which is thereby rotated in the direction of the arrow 101 and' carries with it the collar l0", which is suiciently held to it by the spring pawl 10g, until the collar reaches the position shown in Fi 6 where the pawl ll encounters the note llli and thereby prevents lurther rotation ot the collar.

During the remainder of the withdrawal of the turret the nut l0 is rotated within the collar l0b by the screw 10, such rotation being permitted by the pawl 10g.

Shortly before the w1thdrawal ot the turret is completed the spider arm l passes clear of one end of the abutment 11d and of the end llc of the crank arm 1lb, which thus sets tree the pawl ll to entier completely the notch l0 in the collar l0b (as shown in dotted lines in Fig. 6b) and lock it against rotation in either direction.

The turret with its housing 2 now commences to return under the action of the crank 6, but reverse rotation of the nut l0a being prevented by the pawls l0g and ll, t-he turret itself is compelled to rotate under the action of the screw 10, and does so during the first p-art of such reverse motion ot lld, an air or liquid check l2, (Fig. 6)

which may comprise a cylinder with a suitably leaky piston therein and a spring to lift the piston, is fixed in the bed of the machineso that the end l2 of the piston rod is pressed upon by the arm llf when this is encountered by the spider arm just before it reaches the abutment 11d, and thereby the energy of the rotating parts is absorbed without shock.,

Work spindle dri/ve.

ln order to rotate at suitable variable speeds the two work spindles, which during any grinding operation carry respectively the disc of glass being rough ground and the disc being inish ground, l fix upon one end of the constant speed worm shaft 6 a stepped cone pulley 13, Fig. 1, adapted to meente v positions, and which in the drive aband 13, whchin turn drives another stepped-cone pulley 13b on one end of a small countershaft 13c mounted on `an arm of the bracket 2h fastened to one end of the housing 2 ( Fi 2, 4 and 5).

The steppe cone pulleys 13 and 13b are preferably arranged to give a series of speeds progressing in geometric ratio, and may be exchanged'so asto extend the series.

1t is to be understood thatfli do not limit myself to the particular means described Ifor varying the speed of the counter shaft 13C.

Upon the other end of the countershaft 13c lf mount a pulley 13d adapted to drive a band 13f, which in turn drivesthe pulleys attached to 'the work spindles, which are respectively in the roughing and finishing ositions shown in the drawing are the spin le 3b and 3 and pulleys 3jl and 312.

Upon therotation of the turret, after the completion of each grinding operation, when the finished lens of the spindle 3- is transferred to the top position marked 3, its pulley passes out of range of the band 13t and ceases to be rotated, as is seen to be the case in Fig. 5'.

Clamped in holes in suitable bosses in the bracket 2h coaxially with the work spindles in the positions 3 and 3b are cylindrical fiatended abutments 2i and 2j (Figs. 1 and 2) respectively adapted as yaforesaid to take they end thrust of the grinding wheels on the said work spindles and secure uniformity in the thickness of thelenses ground.

Sliding in a counterbore hole in the bracket 2, coaxially with the idle Work spindle in the position 3a, is a spring urged plunger 2k (Figs. 2, 12, 13) with a head 2l adapted to be thrust by a spring 2m against y a diametrical flat face 2n formed by cutting a gash half way through one side of a shaft 2 journalled in a cross hole in the bracket 2h, and having a cranked lever 2P by which it may be rotated manually so as to thrust the plunger 2k against the tail end of the spindle 3i so as to open the chuck 3h and set free the finished lens, which is then replaced by a fresh disc (Figs. 5, 12, 13).

Rough. gw'awlng wheel. The abrasivel'wheel 4 (Figs. 1 and 2) which is used for the first rough grindlng operation, may conveniently be as indicated in the drawings of ordinary disc form and be mounted in the usual manner on a spindle 4a housed in suitable bearings 4" and 4, which may be provided with any wellknown v form of adjustment for wear, and have spherical exteriors so as to be self aligning, and be attached to bosses 4d and 4 on a carrier frame 4f adjustably mounted on the bed 7 of the machine.

In order to provide for setting the axis of the wheel 4 -to lie in the same plane as and to intersect the axis of the roughing work spindle 3", and thereby grind a cavity in the face of .the glass disc corresponding to the curve of the wheel 4, or to set the wheel above or below said position so that it may grind a bevel toward the outer edge of the face of the disc and prepare it for receiving convex curvature from. the finishing wheel; also in order to adjust the thickness of the lens and fon-Wear of the wheel, ll attach the carrier frame 4f to the front of the bed 7 so that it may slide on a vertical faced bracket, 4H attached to the bed, and be secured adjustably thereto by bolts 4h and 4*, the former of which passes through a vertical slot 41, Fig. 2, in the frame 4i and a horizontal slot 4k in the bracket 4g, whereby vertical and horizontal movement and adjustment of the wheel 4 is permitted.

1n order to effect such vertical adjustment, the bolt 41 fits freely in a hole in the carrier 4", and is confined in a vertical slot. 4l in the bracket 4g, wherein its head is free to move vertically, and in which it may be moved'by means of the screw and hand wheel 4m so as to move the carrier up or down.

In order to effect movement of the wheel in a more or less horizontal direction, the carrier 4t may be swung round the bolt 4i by meansof the adjustable stay 4, (Figs. 1 2, and 4) Which is shown as comprising a tubular member containing at one end spherical seatings 4 and 4P adapted to engage a vtion Serial No. 128,235 a radial step'or terrace may be formed on the glass.

The Vwheel 4 may be partially encircled by a guard 4", vand water is supplied to the wheel in the manner usual in grinding operations and by suitable piping, which, however, to save "confusion is not shown in the drawing.l A

Any suitable means for driving the wheel may be employed. As shown the shaft of the wheel has fixed to it a'pulley 4W over which passes a driving belt 4". The belt is carried down under guide pulleys 4y and 4Z (see 'Figures 1, 2 and 4) from which latter pulleys it passes over a driving Wheel, not shown, which may receive power from any suitable source. The pulleys 4y are mounted yon the carrier 4t so that they follow the adifieaoea position of the latter.

Finishing wheel.

ln the present embodiment of my invention l have shown the means for finishing the grinding of the lens surface as com rising a cup shaped wheel 5 provided wit an annular grinding edge. This cup shaped iinishing wheel 5 is mounted on shaft 5a (see Figures 1 2 and 3) which is journalled in self aligning bearings 5b and 5C, which are mounted on brackets projecting from a carringe' 5f, thev axis of rotation of said wheel being located inthe same hormontalv plane as the axis of the work spindle 3 supporting the work for the finishing operation. llhis carriage is mounted to reciprocate in a direction parallel to the shaft 5'l upon a guideway 5' `formed on a second carriage 5e. A hand screw 5g is provided to reciprocate the carriage 5f upon the carriage 5e. The carriage 5e is in turn mounted to. reciprocate on a guideway on the swivel head 51, hand screw 5h being provided to move the carriage. The direction of movement of the carriage 5 on the swivel head 5i is at right angles 'to the direction of movement of the carriage 5f upon the carriage 5e. rlhe swivel base 5l is rotatably mounted on an annular bearing 51 formed on the machine bed 7, and is adapted to be clamped in any desired angular position by a clamping screw 5. To facilitate theproper setting of the swivel head the latter isshown as provided with a graduated vscale 51, the desired marking on which may be placed opposite to a pointer 5, fixed to the machine bed 7. With the construction illustrated it will be seen that a universal mounting of the wheel 5 is provided so that the periphery of the latter may be brought into any desired relation to the face ot the work on the work spindle 3. The axis of the swivel 5 intersects the work spindle axis at or near the operative point ot the wheel so that the latter may be moved on its swivel without being displaced laterally on the work.

'The grinding wheel 5 is set with its axis of rotation in, or approximately in, a plane in which the axis of the work spindle 3 lies and the wheel is so set that as it rotates its annular grinding edge will sweep over the center of the glass disc carried by the work spindle 3. The axis of the grinding wheel 5 is set `at an angle to the work; spindle 3 so that there is ground on the face of the glass disc on the spindle 3 a portion of a sphere whose radius depends on the diam.- eter of the annular edge of the wheel and on the angular relation between the axis of the work spindle 3 and the axis of the grinding wheel, which angle is indicated by the graduated scale 5q and the pointer 5. By setting the axis of the grinding wheel at an angle at one side of the axis of the work spindle 3, a convex surface may be ground upon the glass disc, and by setting 1t at an angle at the other side. ot the axis or' the spindle 3, by swinging it upon the swivel 5i, a concave surtace may be ground upon the glass disc.,

'.lhe wheel 5 is preferably surrounded by a casing 5m 'secured to the carriage 5f by bolt and nut 5, and a; pipe 5 is provided for supplying water or other cooling agent to the wheel.. As illustrated, the pipe 5 discharges the water near the center ot thewheel fromV which position the water will be gradually ted out to the periphery by centrifugal action.

Means are rovided tor rotating the wheel 5 in any position in which itl may be set.

ln the construction illustrated these means v which passes a driving belt 14:.A The driving belt is carried over the guide pulleys 15 and 16 and then over a 'suitable driving pulley, not shown, then passin over guide pulleys 17 and 18, and back to ghe pulley 5. The pulleys 15, 16, 17 and 18 are movably mounted so as to maintain the belt in proper relation to the pulley 5D for any adjustment of the wheel 15. As shown a standard 20 rises from the machine ,bed 7 and has swivelled to its upper end a horizontally projecting,` arm 19, whichvcarries between its ends a stud 19a, and at its outer end a Second stud 21". Mounted on the stud 2lb is an arm 21, the outer end if which is downwardly turned and connected to a support- Operation.

The Wheels d and 5 are first adjusted in the manner set forth with relation to the work spindles 3" and 3, respectively, so that they will produce the desired cut" upon the lens blanks held in the chucks of these spindles. The machine is then started, the turret being, however, held stationary and in its advanced position by the rod 9, which engages the pin 9, the handle 9 being in its horizontal position as shown in Figures 1 and 2. The operator then moves the handle 2P up to open the chuck 3sa so as to permit the glass disc or lens blank to be inserted. After this has been done the operengage the pin 9, this permitting the shaftiro 651,4and the crank 6 to be rotated by the mechanism described, so as to draw back thel slide 2 and the turret 1. Thls movement causes the spider arm 1r to clear the stop l1d and also causes the screw 10 to rotate the nut 10a, as. already described. When the slide has reached `the rearward limit of this movement the continued rotation ofv the crank 6 starts to advance the turret and slide which, through the action of the screw 10 and nut 10, which is now held stationary, results first in the rotation of theturret. The rotation of the turret, however, brings the spider arm 11 into a position where it engages the stop 11", this preventing further rotation of the turret .and holding it in a'position where the glass disc, whichhas just been placed in the chuck on the spindle 3, is ready to be advanced `into contact with the roughing wheel 4:.'

' fast feed mechanism including the worm wheel 6P, but that during the latter part of the forward movement of the turret the slow feed mechanism, including the worm wheel 8, will come into play in the manner already described. This slow feed mechanis'm causes the worm to be advanced very radually towards the grinding wheel as t e actual grinding down of the glass takes place. Furthermore, as the turret approaches the forward limit of its movement it will be seen that the crank 6 is approaching its forward dead center, so that the advancement of the work becomes very adual and eventually ceases altogether, t is resulting in the work dwelling momentarily in its most advanced-position, which permits the grinding wheel to produce a good finish on the lens surface. In cases wherek the lens blank is thinner than normal, so that the slow feed mechanism comes into action before the surface of the glass disc reaches the grinding wheel, then the operator may pull on the handle 8z so as to operate the hand feed mechanism and ad- Vance the work rapidly, until it is brought to a position for the actual grinding to begin. The glass is then' fed forward slowly by the slow feed mechanism as before. As the slide 2 and turret are withdrawn the pin 2 engages the handle 9e and knocks the same into horizontal position so that further withdrawal and 'further rotation of the turret cannot take place until the operineaoea ator has removed the nished lens from the idle chuck and replaced it with a new blank and then moved the handle 9" back: to its vertical osition.

Each t1me the turret is withdrawn and r0- tated it will be seen that the lens blank, which has been rough ground by the wheel 4.- will be moved to a position where upon the next advancement of the turret it will be acted upon by the finishing wheel, at the same time that the newly' inserted blank is acted upon by the roughing wheel 4.

The work spindles opposite to the wheels 4 and 5 are continuously rotated by the band 13, while the third spindle which is having the finished lens removed and the new blank inserted, remains stationary. Each time the turret rotates, the pulley on the spindle carrying the finished lens is moved out of contact with the band while the pulley on the spindlev carrying the newly inserted blank 1s brought into drivingengagement with the band.

rom the foregoing it will be seen that I have provided va grinding mechanism, which is chiefly automatic in its action and in which the'operations of removing the completed work and inserting a new blank, of rough grinding a blank, and of finish grinding the surface of the work, are carried on simultaneously. The feeding of the work to the grinding wheels is automatic. The machine requires attention onthe part of the operator only for the insertion and removal of the work and for starting the machine, means being provided to prevent the operation of the turret before the finished lens has been taken out, and the new ,blank inserted. The machine is also adjustable so that vthe desired character of work can be produced.

By feeding the finishing wheel forward axially on the guideway 5cl as the wheel becomes worn I compensate such wear and 4 secure uniformity of thickness of the lenses without changing the radius of the curve ground upon them; and by feeding the work and the said wheel relatively toward one another in the direction of the work axis during each operation I keep the abrasive edge of the wheel at all-times crossing the lens axis and thereby promote both the durability of the wheel and accuracy of the surfaces formed on the lenses.

While I have described but one specific machine embodying my invention, which is particularly adapted for the grinding og lenses in accordance with the method whic I have set forth in my aforesaid application for patent, Serial No. 128,235, this description is to be understood merely as illustrative of one preferred embodiment of the principle of my invention, and 1, therefore, do not intend to limit myself to the particular structure described, but intend to iaeaoae set forth are adapted to grinding machines each of said operating in other ways than in accordance with my improved method referred to, and are applicable to machines for the production of other articles than lenses.

What l claim is:

1. ln grinding apparatus, the combination with operation performing means, of a turret carrying a' plurality of work spindles, means for intermittentl rotating the turret to bring the work spin les successively into operative axial position with relation to the operation performing means, Vand means comprising a shock absorbing-device for arresting the rotation of .the turret when said spindles are roperly positioned. 1 2. In grinding apparatus, the combinatie with operation performing means, of a tur- ,ret carying a plurality of work spindles,

means for producing relative approaching and separating movements between the turret and operation performing means, and means operated by such movement for intermittently rotating the turret to bring the 'work spindles' successively into operative-A axial position with relation to the operation performing means.

3. ln grinding apparatus, the combination with operation performing means, of a mem-A ber carrying a work spindle, means for intermittently moving said member to `bring the work spindle successively into operative axial relation with the operation performing means and into an idle position in which the work ma be attached to and removed from the spin le, and means comprising a shockabsorbing device for arresting the movement of said member as` the spindle approaches ositions.

4. In grin ing apparatus, the combination with operation performing means, of a turret carrying a plurality of work spindles, means for intermittently rotating the turret to bring the work spindles successively into operative axial position with relation to the operation performing means, and then into an idle position in which the work may be attached to and, removed from the spindles, and means comprising a shock absorbing device for arresting the rotation of the turret when said spindles are properly positioned.

5. ln grinding apparatus, the combination with operation performing means, of a turret carrying a plurality of work spindles,

means for intermittentl rotating the turret to bring the work spin les successively into operative axial position with relation to the operation performing means and then into an idle position in which the work may be attached to and removed from the spindles, means for rotating the spindles when in operative relation to the operation performing means, the spindles. when in said idle osition being disconnected from said spindle rotating means, and means comprising a shock absorbing device for arresting the rotation of the turretl when said spindles are properly positioned.

6. lin grinding apparatus, the combination of a plurality ofy means for performing different operations, a turret carrying a plurality of workA spindles,- means forproducing a relative approaching and separating movement between the turret and the operation performing means, means operated by such movement for intermittentl rotating the turret to bringt'he work spin les successively into operative axial position with relation to the successive operation means, and into an idle position where the work may be removed from and attached to lthe spindles, and means for rotating the spindles when in operative relation to the voperation performing means, said spindle rotating lmeans being inoperative with respect to the successive spindles when .such spindles respectively occupy said idle posi# tion. f

7. lin ding apparatus, the combination with operation performing means, of a turret carrying a plurality of work spindles, and means comprising coacting parts operperforming sav able by a relative movement between the same longitudinally of the turret to inter- .mittently rotate the .turret to bring the Work spindles successively into operative position with relation to the operation performing means.

8. In grindin a paratus, the combination of a grinding w ee means for rotatin said wheel, a turret, a plurality of work spindles rotatably supported by said turret, means for producing relative approaching and separating 'movements betweenv said spindles and grinding wheel, means for intermittently rotating said turret so as to bring said spindles successively into operative position with respect to said grinding wheel, means for rotating each of said spindles when in operative position, and means for setting the axes of said grinding wheel and of the adjacentspindle intoand out of a common plane.

9. ln grinding apparatus, the combination of a rough'grinding wheel, a finish grinding wheel, means for rotating said wheels, a turret carrying a-pluralit of work spindles, means for producing reliitive approaching 4,and separating movements between saidl spindles when in alient with said grind- `ing wheels, said spindle rotatin means `being inoperative to rotate said spindles when the latter occupy said idle position, lmeans for setting the axes of one of said grinding wheels and of the adjacent spindle into and out of a common plane, and means for setting the axes of the other grinding wheel and of the adjacent spindle at various angles to one another substantially -in one plane. 10. ln grinding apparatus, the combination of a grinding wheel, means for rotating said Wheel, a'turret, a plurality of work spindles rotatably supported thereby', means for producing relative approaching and,al separatlng movements between said spindles and grinding wheel, means for intermittently rotating said turretso as to bring said spindles successively into operative position with relation to said grinding wheel, means for rotating each of said spindles when in operative position, and means for setting the axes of the grinding Wheel and of the adjacent work spindle at various angles to one another substantially in one plane.

11. lln grinding apparatus, the combination of a rough grinding wheel, a finish grinding wheel, means or rotating said wheels, a turret, a plurality of work spindles rotatably supported thereby, means for producing relative approaching and separating movements between said turret and grinding Wheels, means for intermittently rotating said turret so as to bring said spindlessuccessivelyinto operative ositionmeans for rotating each of said spindles when in operative position, first with said rough grinding wheel and then with said finish grinding wheel, means for sett-ing the axes of said rough grinding wheel and the adjacent spindle into and out of a common plane, and means for setting the axes of said finish grinding wheel and of the adjacent spindle at various angles to one another substantially in one plane.i

12. In a spherical inding machine, the combination` of a word;r spindle, an annular grinding wheel arranged to operate across the face of the work carried by said spindle, and a' support for said grinding wheel adapted to retain the axis ofthe grinding wheel substantially in a common plane with the axis of the work and 'comprising a member adjustably pivoted about an axis perpendicular to said commonplane and a ymounting Jfor the grinding wheelu on said pivoted member including means or moving said grinding wheel erpendic-ularly to its axis in said common p ane.

13. In spherical grinding apparatus, the combination of a work spindle, a rotary grinding wheel arranged to operate by its rotation across the face of the work carried by said spindle, and means whereby the axes of the grinding wheel and the work rasante spindle may be set at various anglesv to each other substantially in one plane con ,sisting of a mounting pivoted upon an' axis at right angles to said plane and approximately intersecting the axis of said spindle at' the face of the work andY means for adjusting the mounting about the axis on which it is ivoted to change the radius of the spherically curved surface formed upon the work.

14C. ln grinding apparatus, rotatable worlr carrying4 means', a rotary grinding wheel adapted to work in continuous contact across the face and axis of the work, means for moving lthe wheel in the direction of its axis for setting it in adjusted position, and separate means for automatically causing a relative approaching feeding movement between the work and the wheel inthe direction of the axis of the work;

15. lln grinding apparatus, a work spindle and chuck' for the work, a rotary grinding wheel adapted to operate in. continuous contact across the face and axis of the work, means adapted to vary adjustably the mutual inclinatlon of the work spindle and ygrinding wheel axes, means for adjustably moving the ywheel in the direction of its axis to or from the work, and means for causing a relative approaching feedin movement between the work and the whee in the direction of the axis of the Work.

16. lin grinding apparatus, the combination of a work spindle, a grinding wheel arranged to operate substantially diametrically 4across the face of the work carried by said spindle, means for adjusting the relative position ofthe axes of the inding wheel and the work spindle for either convex or concave grinding and retaining said axes in fixed relation during a grinding operation, and means for causlng a relative approaching feeding movement between the work spindle and the grinding wheel at a decreasing rate.

17. Grinding apparatus, comprising means for rotating the work about an axls passing through the Surface to be ground, a grinding wheel rotary about an axis substantial y in one plane with and substantially intersecting the axis of the work, said wheel being formed and arranged to contactwith the ground surface of the work along a line extending from one side of said surface through the work axis, the grinding sur face of the wheel moving along said line by the rotation of the wheel, and means for first causing' a rapid relative approaching movement between the wheel and the work, then automatically causing a slow approaching movement, then maintaining said wheel x rasante automatic means for causing a relative approaching feeding movement between the work spindle and the grinding wheel which i is rapid at first and then automatically be comes slower, and manually operated means for temporarily increasing the rate of feed.

19. In spherical grinding a paratus, the combination of a work spin le, a rotary grinding wheel arranged to operate in continuous contact across the face and axis of the work carried by said spindle, the axes of the grinding wheel and the work spindle being set at an angle to one another and substantially in one plane for either convex or concave grinding, and automatic means for causing a relative approaching feeding movement between the work spindle and the grinding wheel at a decreasing rate.

20. In grinding apparatus, the combination of a work spindle, a grinding wheel adapted to operate substantially diametrically across the face of the work carried by Said sgindle, means for rotating said grinding W eel, means for adjusting the relative position of the aXesof the grinding wheel and work spindle for either convex or concave grinding and retaining said axes in fixed relation during a grinding operation, and means for causing an approaching feeding movement between the work spindle and the grinding wheel at a decreasing rate, said last named means including a crank and means for rotating the crank at different speeds.

21. In grinding apparatus, the combination of, a slide, a turret rotatably carried by said slide, a plurality of work spindles carried by said turret, a grinding wheel, means for rotating the same, means for rotating the turret to bring the spindles successively into operative position with relation to said grinding wheel and means for` reciprocating said slide at different speeds to advance the work spindles towards said grinding Wheel, and to retract the same therefrom.

22. In grinding apparatus, the combination of, a slide, a turret rotatably mounted on said slide, a plurality of work spindles carried by said turret, a grinding wheel, means for rotating the same, means for rotating the turret to. bring the work spindles successively into operative position with relation to said grinding wheel and means for reciprocating said slide rapidly and then slowly to advance said work-Jspindles towards said grinding wheel.

23. In grinding apparatus, the combina-v tion of operation performing means, a slide, a turret rotatably mounted on said slide, a plurality of work spindles carried by said turret and means for reciprocating said slide rapidly and then slowly to advance said work spindles towards said operation performing means, and hand feeding means for increasing the rate of advance of said slow feedin slide over the speed of movement which 24. In grinding apparatus, the combination of a slide, a turret rotatably mounted thereon, a plurality of work splndles car-- riedfby said turret, a grinding wheel, means for rotating thesame, means for rotating the turret to bring the work spindles successively into operative position with relation to said grinding wheel, a crank for reciprocating said slide to move said work spindles towards and from said grinding wheel, and a plurality of means for rotating said crank. one of said means operating to rotate said crank rapidly during the rst part of the movement of the turret towards the 'grinding wheel and during the ret'action of said turret and another of said crank rotating means operating to rotate said crank' slowly during the latter part of the movement of said turret towards said grinding wheel.

25. In grinding apparatus, the combination of operation performin means, work carrying means, a slide carrying one of said means and adapted to reciprocate to move when said second member is connected to said shaft. i t

26. In grinding apparatus, the combmation of operation performing means, a slide, a turret rotatably mounted on said slide, a plurality of work spindles mounted on said turret and adapted to be moved towards and away from said operation performing means by reciprocation of said slide, and means for reciprocating said slide at varying speeds, including a rotatable shaft and a plurality of driving gears mounted on said shaft one of which is in constant frictional engagement therewith, and means for intermittently connecting the other gear with said shaft, said frictional connection between said first gear and said shaft slipping to permit the speed of rotation of said second gear to control the speed of rotation of said shaft when said second gear is connected to the shaft.

27. In grinding apparatus, the combination of operation performing means, a slide, a turret rotatably mounted on said slide, a plurality of work spindles mounted on said turret and adapted to be moved towards and away from said operation performin means by reciprocation of said slide, an means

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