US3399496A

US3399496A - Machine for generating toric surfaces

Info

Publication number: US3399496A
Application number: US455232A
Authority: US
Inventors: Cary M Hodson
Original assignee: Textron Inc
Current assignee: Textron Inc
Priority date: 1965-05-12
Filing date: 1965-05-12
Publication date: 1968-09-03
Anticipated expiration: 1985-09-03
Also published as: DE1752466A1

Description

Sept. 3, 1968 c. M. HODSON MACHINE FOR GENERATING TORIC SURFACES 7 Sheets-Sheet 1 Filed May 12, 1965 INVENTOR. CARY M. HODSON f S ATTOFTQNEYS Sept. 3, 1968 C. M. HODSON MACHINE FOR GENERATING TORIC SURFACES Filed May 12, 1965 (\l 5? LL.

7 Sheets-Sheet 2 Sept. 3, 1968 c; M. HODSON I MACHINE FOR GENERATING TORIC SURFACES 7 Sheets-Sheet 5 Filed May 12, 1965 AK -2 93 W mm 2 5 v9 09 a. m! 3w I I- I 31 mm 3 N9 P w! I I I I I I I d d l I 37 @vL oE I n 1. mm mm? mm? mm? NNP v 0Q. m3 041 J AME.

p 3, 1968 c. M. HODSON 3,399,496

I MACHINE FOR GENERATING TORIC SURFACES I Filed May 12, 1965 7 Sheets-Sheet 4 V 1, i l A VII/II IJJLVlI/IA Fig. 6

Sept. 3, 1968 c. M. HODSON MACHINE FOR GENERATING TORIC SURFACES Filed ma 12, 1965 7 Sheets-Sheet 5 Sept. 3, 1968 c. M. HODSON MACHINE FOR GENERATING TORIC SURFACES '7 Sheets-Sheet 6 Filed May 12, 1965 LS-2 x CR 4 c 1OCRA-1 1OCRA 4 R R C m 4 1 M 1 \1 I \l 1 1 5 3 R R 9 C m C m w 1 3 Q 5 4 R HI 1 C C I I] 5 P .A J m 2| R 1 pm CA C 6 P 1 M m A 3 #m m R 2 c 1 m m 5 2 .H-I m a 19 c m 9 8 P 1968 c. M. HODSON 3,399,496

MACHINE FOR GENERATING TORIC SURFACES Filed May 12, 1965 7 Sheets-Sheet '7 1OCRB-1 LS-l qoc I I I 2CR-3 3CR-2 United States Patent 3,399,496 MACHINE FOR GENERATDIG TORIC SURFACES Cary M. Hodson, New Vienna, Ohio, assignor, by mesne assignments, to Textron Inc., Providence, R1, a corporation of Rhode Island Filed May 12, 1965, Ser. No. 455,232 Claims. (Cl. 51-124) ABSTRACT OF THE DISCLOSURE In this generator, the work is swung about an axis perpendicular to the tool axis. The work holder is mounted on an upper slide that is adjustable angularly by a trunnion about an axis perpendicular to the tool axis. This trunnion is mounted on an intermediate slide carried by a lower trunnion adjustable about an axis parallel to the axis of the first trunnion. Separate motors drive the two trunnions and the two slides. Manually adjustable controls determine the positioning of lower trunnion and intermediate slide. Signals from feedback resolvers connected to these two parts determine their precise positioning. A member secured to the base holds the upper slide fixed relative to the base while intermediate slide is being adjusted.

This invention relates to machines for generating toric surfaces and especially to machines for grinding ophthalmic lenses to produce toric surfaces thereon.

A toric surface is a surface which has two distinct circular arc curves in mutually perpendicular reference planes that pass through the surface in directions normal to the curvature thereof. One of these curves is sometimes referred to as the base curve and this term will be used herein. The other curve is referred to usually as either the cross curve or the cylinder curve, the former being the term to be used herein. In the field of optics, these curvatures are expressed in terms of diopters, the diopter values of a lens being derived as the value of the reciprocals of the focal lengths of a lens in meters. The base curve is by normal practice the larger radius curve or the curve of smaller diopter value and the cross curve is of a smaller radius and therefore of a larger diopter value. In certain special cases the curvatures can be the same in which event the lens will be spheric rather than toric, but it is understood that in using the term toric surface, these special cases are also included.

The usual method for generating toric surfaces is to move a lens blank relative to a cutting tool through an arcuate path in which it contacts against a portion of an annular cutting surface on the tool. For example, in grinding a lens, a cup shaped wheel is used having an annular surface of arcuate cross section against which the lens blank is moved while being swung around an arcuate path that passes by the annular edge of the wheel. The lens is held so that its lens axis, that is the line centrally through the lens and normal to the curvatures thereof formed by the intersection of the planes in which base and cross curves are referenced, is held normal to the arcuate path. The radial distance in the base curve reference plane from the axis of swing to the point of tangency of the lens with the annular cutting surface is determinative of the base curve. The cross curve is determined by the diameter of the annular cutting surface, normally a constant, and the angle between the lens axis and the axis of rotation of the cutting tool when the lens axis passes through the center of arcuate section of curvature of the annular cutting surface. The surface so generated can be either concave or convex and this is dependent upon which side of the cutting surface of the tool it is that the axis of swing in the base curve refer- 3,399,496 Patented Sept. 3, 1968 ice ence plane is located. A good discussion of the generation of these toric lenses is found in U.S. Patent 2,589,- 488, issued Mar. 18, 1952, on an application by W. D. Fowler.

Toric surface generators are most commonly used in optical shops where ophthalmic lenses are ground in accordance with prescriptions. Seldom are two lenses of the same shape ground in succession and it is therefore common to find that each grinding machine or curve generator is cutting only a fraction of the time during a working day since each workpiece requires a change in set-up. This also means that the machine operator spends a high proportion of his time setting up his machine. The complicated arrangement of machine slides and adjustable members together with the clamps for securing relatively adjustable members together in adjusted positions after adjustment that have been known and used heretofore do not readily lend themselves to automatic operation and therefore the grinding of lenses has not yet been satisfactorily automated although these operations with their high proportion of set-up time are the type from which the most benefit can be derived by automation.

It is therefore an object of this invention to provide a toric surface generating machine which is readily adapted for automatic and power operation.

It is also an object of this invention to provide a toric surface generator by which adjustment for cross and base curves can be accomplished accurately by power driven mechanisms.

Yet another object of this invention is to provide a compact machine requiring very little space but having a relatively wide range of adjustment.

Another object of this invention is the provision of a completely automated toric surface generator.

It is also an object of this invention to provide a toric surface generator in which data can be preset and thereafter used in an automatic cycle to set-up the machine and to generate a toric surface in accordance with the preset data.

A further object of this invention is to reduce the amount of time required of the operator for set-up and subsequent use of a toric surface generating machine to free the operator for multiple machine control.

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

Briefly, this invention provides a toric surface generating machine in which a work holding member and tool are relatively swung about an axis that is perpendicular to the axis of rotation of the tool. The tool has an annular cutting surface and the relative swing of the work holder and tool causes a workpiece mounted on the tool holder to be moved around an arcuate path in contact with the annular cutting surface. The axis of relative rotation of the work holding member and tool is positionable in coordinate directions so as to provide both base and cross curve adjustments, the construction being such that powered movements are easily achieved. Therefore, present input data stores are includ-able in the mechanism to provide signal outputs representative of the coordinate position of the axis of work holder swing. Motors are operated in response to these signals to make the coordinate adjustments for setup and when the machine is in its set-up condition, a further power source is provided to swing the work holder about its axis. A clear understanding of the invention can be obtained from the following detailed description in which reference is made to the attached drawings wherein:

FIG. 1 is a front elevational view, partly in section, of a toric lens grinding machine constructed in accordance with this invention.

FIG. 2 is a sectional view of the machine of FIG. 1 as viewed from line 2--2 thereof.

FIG. 3 is a sectional view of the machine taken along line 33 of FIG. 2.

FIG. 4 is a section of the machine as viewed from line 44 of FIG. 3.

FIGS. 5 and 6 are section views of FIG. 3 taken along lines 5-5 and 6-6, respectively, thereof.

FIG. 7 is a section of the mechanism as viewed along the line 7--7 of FIG. 1.

FIG. 8 is a section view of the portion of the mechanism shown in FIG. 7 as viewed on line 8-8.

FIG. 9 is a section of a portion of the mechanism as viewed on line 99 of FIG. 1.

FIG. 10 is a section of the machine taken along line 1010 of FIG. 3.

FIG. 11 is a partial view in elevation of a control panel included in the base of the machine shown in FIG. 1.

FIG. 12 is a section view of the portion of the control panel shown in FIG. 11 and taken along line 12-12.

FIGS. 13a and 13b are schematic electrical control circuit diagrams for operation of the machine shown in the above listed figures.

FIG, 14 is a partial view of a lens thickness dial as viewed from line 14-14 of FIG. 4.

The overall layout and configuration of a lens grinding machine constructed in accordance with this invention is shown in FIG. 1. The machine includes a base member 15 which houses and supports the various elements of the mechanism. A spindle motor M-5 is attached atop the base 15 and when energized, operates to rotate a grinding wheel spindle mechanism 17 (FIG. 2) to which it is connected by a drive belt 18 and which is enclosed in a spindle housing 19 also received on top of the base 15. The spindle housing 19 has a work enclosure 20 attached at one end and in which the cup shaped grinding wheel 21. (FIG. 3) is enclosed. The grinding wheel 21 is fixed in the end of the spindle mechanism 17 enclosed in the housing 19 and is rotated at a high rate of speed by the motor M-5 on an axis fixed relative to the base 15. The enclosure 20 is required since cutting fluids are used during a grinding operation and since glass lenses are normally ground with diamond abrasive. The enclosure 20 isolates the fluid and grinding swarf both for machine and operator protection. Grinding wheel spindles and work enclosures for lens grinding operations are well known and any of the specific structures common in the art can be adapted for use on the base 15 in the positions of the

units

19 and 20. The previously cited

Patent

2,5 89,- 488 shows and describes a satisfactory spindle and work enclosure mechanism. Therefore further detail of these units will not be undertaken herein except where necessary in connection with other mechanisms to be described in following passages herein.

Lenses to be ground are mounted on a work holding unit 22 that extends into the enclosure 20 where the lens blank 23 (FIGS. 2, 3) is held in a position adjacent to the grinding wheel 21. The work holding unit 22 is supported on an upper or work slide 24 which in turn is supported on an upper trunnion member 25. The upper trunnion 25 is supported on an intermediate slide 26 for rotation on an axis that extends in a direction perpendicular to the direction of the fixed axis of rotation of the spindle 17 and grinding wheel 21. The intermediate slide 26 is supported in turn on a lower trunnion 27 that is rotatably supported on the base 15. This describes generally the machine arrangement and the major units of the machine. The details of machine construction and its manner of operation are included in the description to follow.

The lower trunnion 27 is mounted directly on the base of the machine as shown in FIG. 1. The lower trunnion includes a spindle 28 extending downward therefrom and fixed securely thereto by machine screws 29, there being only one shown for simplicity. The spindle 28 extends into a housing 30 that is fixed in place in the base 15 by machine screws 31 to form an integral part of the base 15. A pair of tapered roller bearings 32, 33 are received in the housing 30 and these support the spindle 28 and trunnion 27 for rotation on the base at a fixed location, this axis of rotation being parallel to the axis of rotation of the upper trunnion 25 to be described in detail later herein. A motor M-l is supported in the base 15 on a fixed mounting bracket 35 to provide power for rotation or angular movement of the lower trunnion 27 on the base 15. The motor M-1 is connected by means of a gearing unit 36 and shaft 37 to a geared speed reducer unit 38. The reducer unit 38 has an output shaft 39 including a coupling element 40 by which it is connected directly to the lower end of the spindle 28. Thus, the motor M-l is connected to furnish power for angular movement of the lower trunnion 27 on the base 15. The shaft 39 of the reducer unit 38 has an electrical resolver 41 connected to its end opposite the spindle 28 to provide an electrical signal that is a direct analog of the angular position of the shaft 39 and spindle 28 in a well known manner.

The intermediate slide 26 is supported on the lower trunnion 27 for movement relative thereto in a direction transverse to the axis of angular movement of the trunnion 27. The structure permitting this movement is shown in FIGS. 1, 3 and 4. A pair of round

bar slide ways

42, 43 are supported directly on the trunnion 27 and are held in their relative parallel positions by screws 44. The

ways

42, 43 extend in a direction perpendicular to the axis of the trunnion 27. The intermediate slide has a set of four sliding feet 45-48 that extend downward and over the

slide ways

42, 43 and each of these feet includes an arcuate shoe 49 held in place by

screws

50, 51, such as is shown for the foot 45, FIG. 4, and these shoes 49 provide a wear resistant sliding surface to contact against the

ways

42, 43. The intermediate slide 27 has a motor M-3 supported thereon and this motor M-3 drives a lead screw 53 through engagement of a pair of

bevel gears

54, 55 in a gear box 56, these gears being fixed on the motor output shaft 57 and the screw 53, respectively. The screw 53 is engaged through a nut 58 that is secured to the bottom of the slide 27 between the

feet

46, 48 so that as the motor M3 is energized to rotate the screw 53, the intermediate slide 26 is moved along the

ways

42, 43.

An electrical resolver 59, FIG. 9, is provided in the mechanism to produce an analog signal representative of the position of the slide 26 along the

ways

42, 43. A worm shaft 60 extends from the end of the screw 53 and through a gear box 61 attached at one end of the slide 26. The shaft 60 carries a worm 62 that engages with a gear 63 which is fixed onto the rotor shaft 64 of the resolver 59. The resolver 59 is fixed in place in the gear box 61 by screws 52. Therefore when the lead screw 53 .is rotated to move the slide 26, the resolver rotor shaft 64 will be turned correspondingly to alter the resolver analog output signal by an amount proportional to the extent of movement of the slide 26.

The upper trunnion 25 is supported directly by the intermediate slide 26, the structure'being shown best in FIGS. 3 and 4. The upper trunnion 25 is rotatably supported on the slide 26 by means of a large angular contact ball bearing 65 embraced therebetween. A stub shaft 66 is centrally located on the bottom of the trunnion 25 and secured in'place by screws 67. The lower end of the shaft 66 is received in a tapered roller bearing 68 held in place between the shaft 66 and the slide 26 by a nut 69 threaded onto the shaft 66. A worm gear member 70 is also received on the shaft 66 and axially located in the proper position by jack-screws 71. The gear member 70 is rotatable relative to the shaft 66, not being keyed thereto in any manner. The worm gear 70 does have a pin 72, FIGS. 5, 6, fixed therein and which extends upward into a recess 73 in the upper trunnion 25. The pin 72 is embraced between adjusting

screws

74, 75 threaded into

plungers

76, 77 slidably held in the upper trunnion and urged toward the pin 72 by

springs

78, 79, respectively. This construction provides a firm but resilient driving connection from the worm gear and the upper trunnion '25.

The worm gear 70 is engaged by a worm 80, FIGS. 3, 4, that is fixed on a shaft 81 rotatably supported in the intermediate slide 26 for rotation by

bearings

82, 83, and 84. The shaft 81 is connected through a coupling sleeve 85 to the output shaft 86 of a geared motor unit M-2. The resilient connection between the worm gear 70 and upper trunnion 25 described previously is provided in the machine to prevent sudden shock from the upper trunnions engagement with a fixed stop limiting the arc of grinding motion from damaging the geared motor unit M-2. The shaft 81 is adapted at its one end 88 for drive by a crank (not shown) upon release of the sleeve 85 from the shaft 81, the release being effected by removal of a set screw 89.

The upper slide 24 is slidably received on the .upper trunnion 25 to allow relative movement of these two members along a direction in a plane perpendicular to the axes of the lower and

upper trunnions

27 and 25. The upper slide 24 has a pair of

round bar ways

90, 91 fixed on its lower side and these are embraced in upper foot members 9295, FIGS. 1, 3, 4 and 7, that are secured to the upper slide 24 in a manner similar to that by which the

ways

42, 43 are secured to the lower trunnion 27. Each of the feet 92-95, for example the foot 92, FIG. 4, has an arcuate bushing 96 held in place by

screws

97, 98 around the way to provide a wear resistant surface for sliding contact. The upper slide also has a toothed rack 99 formed along one side, FIGS. 1, 7 which is engaged by a pinion 100 that is fixed on the end of a shaft 101. The shaft 101 is journaled in bearings 102, 103held in a brake housing portion 104 of the upper trunnion 25. The shaft 101 extends into an electric brake unit 105 fixed in the housing 104 that is operable to stop and prevent rotation of the shaft 101 in a conventional manner. This, in effect, fixes the upper slide 24 and upper trunnion 25 to prevent relative movement along the

ways

90, 91.

The brake housing 104 is also furnished with a manually operated brake to control the rotation of the shaft 101. The manual brake is shown best in FIG. 8 and is comprised of a collar 106 that is received over the shaft 101 between the bearings 102 and 103. There is a key 107 between the shaft 101 and collar 106 so that the two rotate in unison. A bore 108 extends through the housing 104 in a direction transverse to the shaft 101 and a portion of the collar 106 is exposed in the bore 108 where it is contacted by a pair of braking nuts. 109, that are slidable in the bore 108. The nuts are internally threaded but of opposite hands and a screw 111, having two threads of opposite hands, is engaged through the

nuts

109, 110. The thread in the nut 109 is larger in diameter than that in the nut 110 to permit assembly. The screw 111 is journaled for rotation in a bushing 112 fixed in the housing 104 by a set screw 113. A knurled ring 114 is pinned onto the exposed end of the screw 111 to provide a convenient means for turning the screw and a slot 115 is also provided for engagement by other manual driving means should this be required or necessary. It can be seen that rotation of the screw 111 in one direction will draw the nuts 109,110 forcefully against the collar 106 to stop its rotation while rotation of the screw 111 in the other direction will move the

nuts

109, 110 away from the collar 106 and permits its unimpaired rotation. Thus it is that the shaft 101, pinion 100 and rack 99 provide means for securely locking the upper slide 24 in place along the

ways

90, 91.

The work holding unit 22 shown best in FIGS. 3 and 4, is received on top of the upper slide and is movable in a fixed stroke movement toward and away from the grinding wheel to eliminate and provide, alterna'tely, a

clearance between the wheel 21 and lens blank 23. A pair of

round bar ways

116, 117 are fixed on top of the upper slide 24 parallel to the

ways

90, 91 on the under side of that slide. A set of feet 118-121 are attached beneath the main housing member 122 of the work holding fixture 22. The feet'118-121 are similar to the other b'arway engaging feet described previously and each includes an arcuate way engaging bushing 123 held in place by

screws

124, 125. The unit 22 is moved along the

ways

116, 117 by a reversible electric geared motor M4 that is fixed to a bracket 127, FIG. 4, extending laterally out from the side thereof. The motor M-4 rotates a coupling unit 128 that is shown in section in FIG. 2. It is comprised of an inner cone 129 and an outer cone 130 held together by pressure of a spring 131. This is in effect a friction clutch. The outer cone has a pin 132 fixed therein at an eccentric location and the pin 132 is received in a slot 133 extending vertically along the side of the housing 122.

As the coupling unit 128 is rotated one way and the other, the movement of the eccentric pin 132 causes the unit 22 to be moved one way and the other along the

ways

116, 117. The forward position, or grinding position of the unit 22 is determined by a positive stop 134 fixed to the slide 24 between the

ways

116, 117, FIGS. 3, 4. The positive stop 134 is engaged by a dog 135 depending fro-m the housing 122 when the unit 22 is moved toward the grinding wheel 21. The positive stop 134 includes a plunger 136 that is moved out toward the dog 135 by a spring 137. This plunger 136 is moved into the stop 134 when engaged by the dog 135 to compress the spring 137. This provides a cushioning effect on the mechanism to prevent damage to the gears of the motor M-4 which might otherwise occur if the motor were suddenly caused to engage a rigid stop. The friction clutch provided by the inner and

outer cones

129, 130 further provides protection for the motor M-4.

The work chucking mechanism is supported in the unit 22 and is provided with adjustability independent of the movement of the unit 22 along the

ways

116, 117 to facilitate setting for a desired lens thickness. The chucking mechanism includes a rigid ram 138 that is supported in a bushing 139 and held in place by set screws 140, 141, FIG. 3. The bushing 139 is slidably received through a bore 142 in the housing 122 for axial movement only and is biased away from the grinding wheel 21 by a spring 143 that is compressed between the housing 122 and a flange member 144 secured onto the rearward end of the ram 138 by screws 145. The bushing 139 has a pair of

transverse slots

146, 147 and these are engaged by

pins

148, 149 of a forked yoke 150. The yoke 150 is supported on a pin 151 in the housing and swings thereon about an axis perpendicular to the longitudinal axis of the ram 138. The yoke 150 includes an arm 152, FIG. 2, in which a nut 153 is pivotally supported and the nut is threadly engaged by a screw 154. The screw 154 extends from a crank mechanism 155 that is rotatably supported in a fixed position in the housing 122. Therefore, as the crank 155 and screw 154 are rotated, the yoke 150 is caused to swing and the

pins

148, 149 cause the bushing 139 to move axially within the housing 122. The purpose of the spring 143 is to provide a constant force tending to move the ram 138 away from the wheel 21 and thereby maintain the backlash in the mechanical system in a corresponding constant condition.

The end of the ram 138 toward the wheel 21 is adapted to hold the lens blank 23 during the grinding operation. The blank 23 is mounted on a blocking unit 156 that is cast directly upon the back of the lens blank 23. The block 156 fits snugly into a bushing 157 that is fixed in place in the ram 138 and the bushing. 157 is provided with

appropriate seals

158, 159 so that an air tight closing of the end of the ram is effected. A vacuum line 160 is connected at the rear of the ram 138, FIG. 2, to produce a low pressure within the ram 138 that holds the 7 block 156 in place. The block 156 also has a small center hole through to. the lens blank 23 and a probe 161 extends through it to engage against the back of the lens blank 23. The probe 161 ,is held against the lens 23 by a spring 162, FIG. 2 and also extends out from therea r of the ram 138 through a plug 163 where it is contacted by the sensor 164 of a dial indicator 165 mounted on a bracket 166 attached to the housing 122. The function of the dial indicator 165 will be explained more fullylater herein.

The upper slide 24 is movable on the

ways

90, 91 but this relative movement takes place asa result of the shifting of the intermediate trunnion 25 and. the intermediate slide 26 in unison between the lowervvays 42, 43 andthe

upper ways

90, 91. The upper slide 24 is held in a fixed position relative to the base 15 while the shifting of the' intermediate slide 26 and upper trunnion is accomplished. For this purpose, an arm 167 rigidly fixed to the base 15 is provided and the arm extends outward over the upper slide 24 and below the work enclosure 20, FIGS. 1, 3 and 7. The arm 167 carries a depending member 168 that extends downward from the arm 167 toward the slide 24. The lower end of the depending member 168 carries a stud 169 that is closely embraced in a slot 170 in a turn-table member 171. The turn-table 171 is rotatably received in needle bearings 172 that are supported directly in the upper slide 24. The upper slide 24 is provided with a pair of

plungers

173, 174, FIG. 10, that are engaged against a pair of

pins

175, 176, respectively, which are fixed in the turn-table 171. Each of the

plungers

173, 174 is urged toward the

pins

175, 176 by means of a spring 177, 178, respectively. As long as the turntable 171 is oriented to be transverse to the

ways

90, 91 of the upper slide 24, the forces acting on the turn-table from the Springs 177, 178 are balanced and the turntable 171 tends to remain stationary in the upper slide 24.

The positioning of the upper trunnion 25 and intermediate slide 26 is normally performed when the

upper ways

90, 91 are parallel to the

lower ways

42, 43 and while these ways are in axial alignment with the axis of the grinding wheel spindle 17. Therefore the arm 167 restrains the upper slide with the slot 170 transverse to those ways as described. However, the upper trunnion axis of rotation is in most cases not in line with the axis of rotation of the turn-table 171. Therefore, as the upper slide 24 is swung with the upper trunnion 25-, the stud 169 will trace an arcuate path with respect to the upper slide 24. To permit this and since the arm 167 and stud 169 are rigid with the base 15, the turn-table 171 isrotated against the centering force of the spring 177, 178. At the same time, the stud 169 is moved along the slot 170. The extremes of swinging movement of the upper slide 24 with the upper trunnion 26 for any given position of the upper trunnion below the upper slide are determined by fixed stops 179, 180 at the ends of the slot. The purpose of the yieldable drive to the upper trunnion through the

springs

78, 79, FIG. 6, previously described, is to prevent damage to the geared motor drive thereto when the stops 179, 180 are engaged by the depending stud 169. The turn-table 171 carries an enclosure 181 through which the member 168 and stud 1 69 extend and which extends over the length of the slot 170. The enclosure 181 provides a mounting surface to which a pair of limit switches LS-4, LS- are attached and positioned for operation by the member 168 when that member is at one end or the other of the slot 170. The signals produced by these switches LS-4, LS-S are used in controlling the automatic machine cycle which will be described later herein. Since the turn-table 171 is located at a position below the grinding station of the machine, it has been provided with a cover plate 184 that is supported from the member 168. A hearing 185 is provided between the plate 184 and the member 168 to provide free relative rotary movement of the plate 184 with respect to the member 168. A flexible pleated boot 186 8 is connected between the plate 184 and the upper slide 24 to provide a complete enclosure around and over the turn-table 171. The bearing is required between the member 168 and plate 184 since the angle of the arm 167 relative to the upper slide 24 changes during a swing of the upper slide 24 in a grinding operation and a drag would otherwise result through twisting of the boot 186. i The. grinding machine described is arranged to facilitate completely automatic operation to grind a lens in accordance with preset information. In FIG. 11 there is shown apartial view of the electrical control cabinet 187 that is attached to the base 15 of the machine. The cabinet 187 includes two

dials

188, 189 for presetting the desired cross curve and base curve specifications in diopters. The dial mechanisms are shown in cross section in FIG. 12, each being the same as the other in arrangement andoperation. The dial 188 is fixed on the end of a shaft 190 that is rotatably received through a bushing 191.'The bushing 191 is fixed in a stiffening plate 192 that is fixed in place in the cabinet 187 by screws 193, shown slightly out of position in FIG. 12. The axial position of the shaft 190 is maintained by a nut 194 that is turned onto the shaft and against a bearing 195 that in turn is held against the plate 192 and bushing 191. The inner end of the shaft 190 is journaled in a bushing 196 fixed in a rear support plate 197. A pinion 198 is fixed on the shaft 190 and it meshes with a gear 199 that is in turn fixed on the rotor shaft 200 of an electrical resolver 201. The gear 199 is a backlash free gear comprised of two halves biased 'by a yieldable means such as a spring (not shown) to relatively counter rotate. Gears of this type are Well known in the instrument gear art. The resolver 201 produces an electrical signal output that is directly proportiona] to the angular position of the dial 188 The dial 189 is similarly connected to another resolver 202'which produces an electrical output proportional to the angular position of that dial 189.

The signals from the

resolvers

201, 202 are connected electrically in servo control loops that determine the positioning of the lower trunnion 27 and the intermediate slide 26, respectively. The final positioning of these two members is determined through a comparison of the signals from the

command resolvers

201, 202, respectively, against the signals from the feedback resolvers 41 (FIG. 1) and 59 (FIG. 9) previously described in accordance with conventional servo-mechanism practice. The

dials

188 and 189 are each calibrated in two directions from a zero reference to produce movement of the appropriate members controlled thereby to positionswhere the machine described will be set to grind a lens having cross and base curves in accordance with the angular position of the dial relative to a scribed reference mark on the face of a

ring

203, 204, respectively, fixed onto the cabinet around the

dials

188, 189. The lens will be convex or concave inaccordance with the one of the two scales of each dial used in setting the machine. The convex and concavescales are indicated as PLUS and MINUS, respectively, on the

dials

188, 189. .I The base curve of a lens as generated by the machine is a result of the swing of the upper slide 24 with the upper trunnion 25 and is purely arcuate. Therefore there is no error introduced as a result of any approximation in that curve. Therefore the ring 204 has a single fixed reference zeroymark thereon. The cross curve is an approximation, however, since the efiective diameter of the wheel 21 always is the same and the different cross curve radii are produced by varying the approach of the lens blank around the cutting edge. This gives a close approximation but the true'curve is elliptical ratherthan circular. The result is a small error such as is discussed in some detail in the previously cited patent. The ring 203 is provided with two scales to provide a convenient means to offset of the zero reference one way and the other in accordance with the base curve diopter setting and the direction (plus or minus) of that curve. These corrective scales are shown in FIG. 11 and are labelled therein for clarity. In setting the dial 188 to produce a selected cross curve, the appropriate diopter index mark in the dial 188 would be positioned opposite to the corrective scale mark, plus or minus, corresponding to the setting made on the base curve dial 189. The resulting lens would be more nearly correct with a minimized elliptical error and less corrective lapping of the lens will be required in the post grinding treatment. The relative spacing of the corrective indicia is obtained by plotting the actual curves obtained and the ideal curves and scaling the correction in accordance with the difference.

The lens thickness is adjusted by use of the crank 155 and dial indicator 165 which have been described previously. The dial portion associated with the crank 155 is shown enlarged in FIG. 14. A stationary thickness dial 205 is attached to the side of the housing 122 and is provided with two marked scales calibrated in millimeters, one for lenses having a plus curvature and one for lenses having a minus curvature. The back side of each lens blanks has a known spherical curvature and the crank 155 is provided with a dial 206 which has markings representative of the range of curvatures of the blanks to be ground. In setting the crank to a desired lens thickness, the crank 155 is rotated until the mark on the dial representing the curvature of the back face of the particular lens blank is in alignment with the desired thickness marking on the dial 205. The dial indicator 165 should read zero at this time, but since the crank mechanism is not as precise as desirable, the crank 155 may require additional small adjustment until the indicator is at its zeroed condition. The normal range of lens thicknesses requires multiple rotations of the pointer in the dial indicator 165 and therefore the crank mechanism serves as a revolution counter and rough positioning system but final accuracy is dependent upon the dial indicator 165.

The machine is provided with an automatic cycle control system. The

dials

188 and 189 can be preset for a prescribed lens while the machine is in operation on another lens. The thickness crank 155 cannot be preset however. When the machine has completed its cycle on the presently chucked lens, it stops. The operator removes that lens and places the next lens in the ram 138. The

dials

188 and 189 have been present for this next lens. The thickness adjustment, if a change is required, can be made now. The operator then initiates the automatic cycle. The upper and

lower trunnions

25, 27 are swung to align the

ways

90, 91 and 42, 43 parallel. The intermediate slide 26 is then shifted to a position corresponding to thte setting of the base curve dial 189. After this is completed, the lower trunnion is swunk in accordance with the setting of the dial 188. When this is completed, the machine is ready to grind. The operator initiates the grinding cycle and the work holding unit 22 is advanced toward the wheel 21. The upper trunnion 25 is then swung to move the blank 23 past the wheel in a feed and grinding movement. After this, unit 22 is then retracted and the cycle is complete and the ground lens can be removed. The automatic cycle can be repeated with new settings that have been dialed into the system during the actual grinding operation.

The circuit for the control of the machine to produce the described cycle is shown schematically in FIGS. 13a, 13b. The circuit employs sevent limit switches LS1 through LS-7 as signal feedback units to provide various function signals from the machine. The switch LS-1 shown in FIG. 1 is mounted on the base below the lower trunnion 27 where it is engaged by dogs (not shown) when the trunnion 27 is swung in either direction to the limit of its swing. The switches LS2 and LS-3 are each mounted on side of the intermediate slide 25 and are located on opposite sides of that slide. The switch LS-2 is shown in FIG. 1 and it is operated whenever the upper trunnion 25 is swung to a position that is counterclockwise from the position in which the

upper ways

90, 91 are parallel with the

lower ways

42, 43. The switch is not operated when the

upper ways

90, 91 are swung clockwise due to a clearance 207 formed under the upper trunnion 25 where the switch LS2 is in contact. The other switch LS-3 (not shown in FIG. 1) is similarly mounted on the back side of the slide 26 but is operated whenever the

ways

90, 91 are swung clockwise from parallel position (as viewed in FIG. 2). The switches LS-4 and LS-S are mounted, as described previously, on the cover 181 over the slot 170 in the turn-table 171 (FIG. 7). These switches LS-4, LS-S are operated whenever the upper slide 24 and upper trunnion 25 are swung to their full counter-clockwise and clockwise positions, respectively. The other switches LS-6, LS7 are mounted, as shown in FIG. 3, on the upper slide 24 and are engaged and operated by the dog when the work slide unit 22 is retracted and advanced, respectively.

In describing the circuit of FIGS. 13a, 13b, a cycle of operation will be followed through to detail the relationships of the various circuit elements and their sequence of operation. It is initially assumed that a new set of prescription values have been recorded by selected positioning of the

dials

188 and 189 and that the previous cycle has ended with the work holding fixture 22 in its retracted position. There is an error signal at the intermediate slide error amplifier 208 and when such an error exists a signal is applied through a conductor 209 to energize the relay 11CR. Similarly an error is present in the lower trunnion error amplifier 210 and a signal is connected to a conductor 211 to energize the relay 13CR. Since the work holder 22 is retracted, the limit switch LS-6 is operated and the relay 6CR is also energized. At this point, the machine operator has chucked a new lens blank 23 in the ram 138 and has set a selector switch 18W in the regular grind position shown which will produce a clockwise rotation of the upper trunnion 25 in the grind portion of the cycle. The machine operator now presses a set switch 2SW momentarily and a pair of relays IOCRA and ltlCRB are energized through contacts 6CR-2 and 13CR-1 or 11CR'1, all of which are now closed. (Note, contacts of relays correspond in designation to the respective relays with a suffix number to identify particular contacts.) A latch is closed parallel to the switch 2SW through contacts 10CRA-6 to hold the relays 10CRA, IOCRB energized upon release of the switch 2SW. The upper trunnion 25 and lower trunnion 27 must correspond in angular position prior to movement of the intermediate slide 26. If it is assumed that the previous cycle was regular, the upper trunnion is in a position clockwise from the desired parallel position and the limit switch LS-3 is closed and the relay 3CR is energized. Since the relay 11CR is energized as described, the contacts 11CR-3 are closed and a circuit is complete from the switch 2SW through contacts 11CR-3, 3CR-1, 10CRA-5 and normally closed contacts M2CW-1 of a relay M2CW. (Contacts that are normally closed, that is closed when the relay is deenergized, are shown throughout like the contacts MZCW-l.) The relays M2CCW and 12CR are energized at this time and the contacts M2CCW-3 are closed and the contacts M2CCW- 2 are opened. The contacts M2CW-2 are closed and the motor M-2 is connected to swing the upper trunnion counter-clockwise toward the parallel position. Since the relay 6CR is energized, the feed rate control voltage control unit 212 is connected to the motor M-2 for rapid operation through contacts 6CR-3, 12CR-1 and 6CR-5. This causes the motor M-2 to operate at its fastest rate to move the upper trunnion toward its parallel position.

If the upper trunnion 25 is positioned counter-clockwise from the parallel position, the limit switch LS-2 is closed and the relay 2CR is energized. The relays MZCW and 12CR are then energized through a circuit including the contacts 2CR-2, 10CRA-3 and MZCCW-l. The

1 1 motor M-2 is then energized through the contacts M2CW3 and MZCCW-Z to cause a reversed drive of the trunnion in the clockwise direction toward the parallel position.

When the upper. trunnion 25 reaches its parallel position, the switches LS2 and LS3 are both open and the relays 2CR and 3CR are both deenergized. The relays MZCCW and 12CR are deenergized (also M2CW if it is energized instead of MZCCW). The upper trunnion 25 then stops at or near the parallel position. The yieldable drive connection to the upper trunnion, previously described, will allow for a slight misalignment. The intermediate slide error amplifier 208 is then connected by way of relay contacts 3CR-2, 2CR-3 and CRB2 to output a signal to one or the other of the relays M3L or M3R through contacts M3R-1 or M3L-1, respectively. The relay energized depends upon the direction of movement of the slide 26 required to null the signal from the amplifier 208. The slide 26 is then driven by the motor M-3 which is energized either through the contacts M3L-3 and M3R-2 or M3R-3 and M3L-2. When the error amplifier 208 is nulled and the intermediate slide is positioned, the relay 11CR is deenergized. It should be noted at this point, that the brake 105 is reset when the relay 11CR is deenergized, the contacts 11CR-4 being closed. It should also be pointed out that if either of the relays 2CR or SCR is energized, the contacts 2CR-4 and 3CR-3 are closed and the brake 105 remains set. Therefore the upper trunnion must be in its parallel position before the brake 105 can be released to permit movement of the intermediate slide 26. The contacts 10CRB-7 provide a holding circuit for the brake 105 after completion of the automatic setting of the machine.

Simultaneous with the movement of the upper trunnion 25 to its parallel position and movement of the intermediate slide 26 to its proper position, the lower trunnion 27 is swung to its proper position in accordance with the setting of the cross curve dial 188. The error signal in the amplifier 210 produces a signal that is connected to one or the other of direction control relays MlCCW and MlCW whenever the relay contacts lflCRB-l are closed. Which of these relays is to be connected for energizing is dependent upon the direction of movement of the lower trunnion 27 required to null the error signal in the amplifier 210. The closing of the contacts MICW along with normally closed contacts M1CCW-2 energizes the motor to operate and swing the trunnion clockwise. If the contacts M1CCW3 are closed in combination with normally closed contacts MlCW-3, the energization is in the reverse sense and the trunnion 27 is swung counterclockwise until the amplifier output is nulled. This can be occurring with movement of the upper trunnion 25 and intermediate slide since these members are supported on the lower trunnion 27 and are moved relative thereto. When the lower trunnion 27 is in the preselected position, the output of the amplifier 210 is nulled and the relay 13CR is deenergized.

'The machine at this time is set for grinding except for swinging the upper trunnion to an extreme position from which the grinding operation will proceed. The positioning of the intermediate slide 26 has resulted in the deenergization of the relay 11CR and therefore the contacts 11CR-2 are now closed. With the selector 1SW as shown, the relays MZCCW and 120R are energized through the contacts 4CR-4, 10CRA-5 and M2CW-1. The motor M-2 is again energized as before to swing the upper trunnion counter-clockwise. When the upper trunnion has swung to its counter-clockwise limit, the switch LS-4 is closed and the relay 4CR is energized. The circuit to the relays M2CCW and 12CR is opened and the motor M-2 stops. The contacts 4CR-3 are opened and the last parallel circuit to the relays 10CRA and IOCRB is opened and these are deenergized.

If the selector switch 18W is in the back grind position,

12 the upper trunnion 25 will be swung to its extreme clockwise position to complete the set-prior to grinding. The contacts SCR-6 and SCR-5 are then used in the same manner as the contacts 4CR4 and 4CR-3 but to energize and deenergize the motor control relay M2CW and the set-up relays 10CRA and 10CRB. The limit switch LS5 will be closed to energize the relay SCR instead of the relay 4CR when the set-up is complete.

The machine operator now momentarily closes the switch 3SW and the relay M5-1 is energized. The contacts of MR-l close in a parallel latch circuit to bypass the switch 3SW. The relay MSR also has contacts (not shown) which close to energize the spindle motor M-5. At this same time, the relay M4F is energized through the limit switch LS7 and contacts 9CR-1 and M4-1. The limit switch LS7 is the switch which signals that the work holding unit 22 is advanced. Contacts of the relay M4F (not shown) are connected so that the motor M-4 is now energized and the work holder is advanced. When the work holder 22 moves away from its retracted position to its advanced position, the relay 8CR is energized through contacts of the switch LS-7 and the relay contacts 4CR-1 which are closed at this time in a normal grinding operation, that is a swing of the upper trunnion 25 from the counter-clockwise extreme in a clockwise direction. The contacts SCR-1 close to latch the relay 8CR energized and the contacts 8CR-2 close and complete a circuit through the contacts SCR-2, 10CRA2 and M2CCW-1 to energize the relays M2CW and 12CR. The motor M2 is energized as before except the selector switch 4SW is connected to select a speed of grinding operation since the relay 6CR is deenergized and the contacts 6CR-4 and 6CR-6 are closed and the contacts 6CR-5 are open. The grinding continues until the trunnion 25 has swung to its most clockwise position where the switch LS-S is closed and the relay SCR is energized. The contacts SCR-2 open and the relays M2CW and 12CR are deenergized. The contacts 5CR-3 are also closed and a circuit is completed to the relay M4R through contacts 6CR-1 and M4F-1. The relay M4R operates contacts (not shown) which reverse the operation of the motor M-4 to retract the work holding unit 22.

In the event that a back grinding cycle has been selected instead of the regular cycle described, the relay SCR is energized at the end of the automatic set-up and the relay 9CR is then energized after advancement of the work holding unit, that relay being energized through the contacts 5CR1 and 4CR2. The relay 9CR is latched energized through its contacts 9CR2. Also, the relays M2CCW and 12CR are energized through the contacts 9CR-2 and 10CRA-4 and MZCW-l. When the grind is complete, the limit switch LS4 is closed and the relay 4CR is energized to open the contacts 4CR-2 and to deenergize the relay 9CR and stop the machine. When the relay 9CR is deenergized, the contacts 9CR-2 open and the relays MZCCW and 12CR are deenergized. When the relay 9CR is deenergized, the contacts 9CR-3 are closed and the relay M4R is then energized through the normally open contacts 2CR-1 and the normally closed contacts 6CR-1 and M4F-1. The relay 2CR has become energized during the grinding operation with the swing of the upper trunnion 25 from its clockwise extreme to its counter-clockwise extreme. The motor M-4 is then energized to retract the work holding unit 22 and when it is fully back, the limit switch LS-6 is operated and the relay 6CR is energized. The contacts 6CR-1 open and the relay M4R is deenergized the machine now stops and does not function again until the set switch 2SW is again depressed.

: The control circuit is arranged such that when a regular grinding cycle is selected, that is with the switch ISW in the. position shown, the cycle relay SCR is latched energized through its own contacts SCR-1 and remains energized until the master stop switch SSW is depressed to interrupt automatic operation. The depressing of the switch SSW also energizes the retract relay M4R ifthe work holding unit 22 is advanced at this time. With the relay 80R energized its contacts 8CR-3 are closed and at the end of the normal grind the trunnion 25 is in its full clockwise position and the limit switch LS-S is operated to energize the relay SCR. Therefore the contacts 5CR-4 are also closed, and as soon as the unit 22 is retracted, the retract signal relay 6CR is energized to close the contacts 6CR-2. Therefore a circuit parallel across the switch 2SW is completed and the set-up cycle is automatically initiated and proceeds as described previously herein except for initiation which does not now require the switch ZSW to be closed. The stop switch SSW also has contacts which interrupt the set-up cycle if the switch SSW should be depressed during set-up rather than grind.

From the foregoing detailed description it can be seen that a fully automated lens grinder has been provided. The machine can be pre-set so that when oen cycle is complete, it immediately automatically arranges itself for the next cycle. The mechanism is compact and provides for a unique cooperation between the various elements. It also provides a convenient mechanism for selecting lens thickness and further provides for the reduction of elliptical error.

What is claimed is:

1. A toric surface generator comprising:

(a) a base,

(b) a tool having an annular cutting surface,

(c) means for supporting and rotating said tool on an axis fixed relative to said base,

(d) a work slide,

(e) means for supporting and swinging said work slide on an axis of rotation perpendicular to the axis of 7 tool rotation,

(f) means for shifting the work slide angularly in a plane perpendicular to the axis of rotation thereof to move said work slide axis of rotation in an arcuate V path having a'predetermined radius to a selected angular position relative to the axis of tool rotation,

(g) means for selectively adjusting the predetermined radius of the arcuate path of movement of the axis of rotation of said work slide,

(h) means for holding said work slide fixed relative to said base while the adjustment of said radius is being effected, and

(i) means for holding a workpiece on said work slide to contact said annular cutting surface and to swing thereagainst when said work slide is swung about the axis of rotation thereof.

' 2. A toric surface generator comprising:

(a) a base,

(b) a tool having an annular cutting surface,

(c) means for supporting and rotating said tool on a fixed axis relative to said base,

(d) a work slide,

(e) means for supporting and swinging said work slide on an axis of rotation perpendicular to the axis of tool rotation,

(f) means for shifting the work slide angularly in a plane perpendicular to the axis of rotation thereof to move said work slide axis of rotation in an arcuate path having a predetermined radius to a selected angular position relative to the axis of tool rotation,

(g) means for selectively adjusting the predetermined radiusof the arcuate path of movement of the axis of rotation of said work slide,

(h) means for holding said work slide'fixed relative to said base while the adjustment of said radius is being 1 effected, i

(i) means for holding a workpiece on said work slide to swing against said annular cutting surface when said work slide is swung about the axis of rotation thereof, and

. V (j) means for adjusting the depth of penetration of said annular cutting surface into the workpiece on said work slide.

3. A toric surface generator comprising:

(a) a base,

(b) a tool having an annular cutting surface,

(d) a work slide,

(e) means for supporting and swinging said work slide onan axis of rotation perpendicular to the axis of tool rotation,

(f) means for moving said work slide axis of rotation in the direction of said axis of tool rotation to a selected position therealong,

(g) means for holding said work slide in a fixed position relative to said base when the axis of rotation thereof is moved in the direction of the axis of tool rotation,

(h) means for angularly shifting said work slide and the axis of rotation thereof about a fixed axis parallel to the work slide axis of rotation to a selected position after movement of said work slide axis along the axis of tool rotation, and

4. A toric surface generator comprising:

(a) a base,

(b) a tool having an annular cutting surface,

(d) an intermediate member,

(e) means for attaching said intermediate member to said base to swing on a fixed axis perpendicular to the axis of rotation of said tool,

(f) a work slide,

(g) means for supporting said work slide on said intermediate member for angular movement on an axis parallel to the axis of swing of said intermediate member,

(h) means for positioning the axis of angular movement of said work slide at a selected distance from the axis of swing of said intermediate member,

(i) means for maintaining said work slide in a fixed position relative to said base when the axis of angular movement of said work slide is being moved,

(3') means for swinging said intermediate member to a selected angular position on said base,

(k) means for angularly moving said work slide about said axis thereof, and

(1) means for holding a workpiece on said work slide to contact said annular cutting surface during angular movement of said work slide.

5. A toric surface generator comprising:

(a) a base,

(b) a tool having an annular cutting surface,

(0) means for supporting and rotating said tool on an axis fixed relative to said base,

(d) an intermediate member,

(f) a work slide,

(g) means for supporting said work slide on said intermediate member for angular movement on an axis in said intermediate member parallel to the fixed'axis of swing thereof,

(h) means for moving said intermediate slide to shift the axis of angular movement of said work slide to a selected position spaced from the fixed axis of swing of said intermediate slide,

(i) means for holding said work slide in a fixed position relative to said base when said intermediate slide is moved,

(j) means for swinging said intermediate slide on said fixed axis thereof to angularly position said intermediate slide and shift the axis of angular move- 15 ment of said work slide to a selected angular position around the fixed axis of said intermediate slide,

(k) means for holding a workpiece on said work slide and adjacent to said cutting tool, and

(1) means for swinging said work slide on said axis of angular movement thereof in said intermediate member for movement past said annular cutting surface in an arcuate path to carry the workpiece held thereon into contact with said annular cutting surface.

6. A toric surface generator comprising:

(a) a base,

(b) a tool having an annular cutting surface,

((1) a work slide,

(e) an intermediate slide,

(f) means for connecting said work slide onto said intermediate slide for rotation on an axis therein perpendicular to the axis of rotation of said tool and for transverse movement relative to said axis of work slide rotation,

(g) means for connecting said intermediate slide onto said base for rotation on a fixed axis parallel to said axis of work slide rotation and for transverse movement relative thereto,

(h) means for shifting said intermediate slide transversely on said base to a selected location,

(i) means for holding said work slide in a fixed position relative to said base when said intermediate slide is shifted transversely on said base to effect a corresponding transverse shift of said axis of work slide rotation relative to said work slide,

(j) means for angularly swinging said intermediate slide on said base to a selected angular position relative thereto to effect a corresponding angular positioning of said axis of work slide rotation around the fixed axis of intermediate slide rotation, and

(k) means for swinging said work slide on said axis thereof in said intermediate slide for movement in an arcuate path past said annular cutting surface.

7. A toric surface generator comprising:

(a) a base,

(b) a tool having an annular cutting surface,

(d) a work slide,

(e) an intermediate slide,

(h) a first motor connected to said intermediate slide and operable when energized to move said intermediate slide transversely relative to said base,

(i) means for holding said work slide in a fixed position relative to said base when said intermediate slide is moved transversely,

(j) a second motor connected to said intermediate slide and operable when energized to swing said intermediate slide around said fixed axis of rotation thereof,

(k) a third motor connected to said work slide and operable when energized to swing said work slide around the axis of rotation thereof, and

(1) means for selectively energizing said motors in a predetermined sequence to adjust the position of said axis of work slide rotation and to swing said work slide past said annular cutting surface in a selected arcuate path.

S. A-toric surface generator comprising:

' (0) means for supporting and rotating said tool on an axis fixed relative to said base,

(d) a first trunnion member received on said base for rotation on a fixed axis perpendicular to the axis of rotation of said tool,

(e) an intermediate slide,

(f) means for supporting said intermediate slide on the first trunnion member for bidirectional movement thereacross perpendicular to the axis of rotation thereof,

(g) a second trunnion member received on said inter mediate slide for rotation on an a'xis'parallel to the axis of rotation of said first trunnion member,

(h) a work slide, 7

(i) means for supporting said work slide on the second trunnion member for bidirectional movement relative thereto perpendicular to the axis of rotation thereof,

(j) means for moving ,said intermediate slide to shift the axes of said first and second trunnion members to a selected spacing,

(k) means for holding. said work slide in a fixed position relative to said base when said intermediate slide is moved,

(1) means for swinging said first trunnion member to angularly orient said intermediate slide in a selected relationship with the axis of rotation of said tool,

(111) means for swinging said second trunnion member to move said workslide past said annular cutting surface in an arcuate path dependent upon the selected distance between the axes of rotation of said first and second trunnion members and the selected angular orientation of said intermediate slide, and

(11) means for supporting a workpiece on said work slide to contact the annular cutting surface during a position of the swing of said second trunnion.

9. A toric surface generator comprising:

(a) a base,

(b) a tool having anannular cutting surface,

(d) a first trunnion member received on said base for rotation on a fixed axis perpendicularto the axis of rotation of said tool,

(e) an intermediate slide,

(f) means for supporting said intermediate slide on the first trunnion member for bidirectional movement thereacross perpendicular to the axis of rotation thereof, a

(g) a second trunnion member received on said intermediate slide for rotation on an axis parallel to the axis of rotation of said first trunnion member,

(h) a work slide,

(i) means for supporting the work slide on the second trunnion member for bidirectional movement relative thereto perpendicular to the axis of rotation thereof,

(j) means for moving said intermediate slide to shift the axes of saidfirst and second trunnion member to a selected spacing.

(k) means for holding said work slide in a fixed position relative to said base when said intermediate slide is moved, t

(1) means for swinging said first 'trunniongmember to angularly orient said intermediate slide in a selected relationship with the axis of rotation of said tool,

(m) means for swinging said second trunnion member to move said workslide past said annular cutting surface in an arcuate path,

(n) means'for supporting'a workpiece from a rearward side thereof on said work slide to contact the annular cutting surface at a forward side of the workpiece a portion of the swing of said second trunnion,

() means for determining the location of the rearward side of the workpiece on said work slide, and

(p) means for shifting the workpiece on said workslide with reference to the indicated location of the rearward side thereof and relative to said tool to adjust the depth of penetration of said annular cutting surface into the workpiece on said workslide, thereby determining the thickness of said workpiece after generation of a toric surface on the forward side thereof.

10. A toric surface generator comprising:

- (a) a base,

(b) a tool having an annular cutting surface,

(d) a first trunnion member received on said base for rotation on a fixed axis perpendicular to the axis of tool rotation,

(e) an intermediate slide,

(h) a work slide,

(j) a first motor on said first trunnion member and connected to said intermediate slide for movement thereof on said first trunnion member,

(k) a second motor in said base and connected to said first trunnion member for angular movement thereof,

(1) means for energizing said first motor to shift said intermediate slide and the axis of said second trunnion member to a selected distance from the axis of said first trunnion member,

(m) means for maintaining said work slide in a fixed position relative to said base when said intermediate slide is shifted on said first trunnion member,

(11) means for energizing said second motor to selectively adjust the angular position of said first trunnion member and swing said intermediate slide to a selected angular position,

(0) a third motor on said intermediate slide and connected to said second trunnion for rotation thereof, and

(p) means for energizing said third motor to swing said second trunnion and carry said work slide in an arcuate path past the annular cutting surface of said tool after said first trunnion and intermediate slide are selectively positioned.

11. A toric surface generator comprising:

(a) a tool having an annular cutting surface,

(b) means for rotating said tool on a predetermined axis extending centrally through the tool,

(c) a work holder,

(d) means for supporting said tool and work holder adjacent to one another and for relatively swinging said tool and work holder about an axis perpendicular to the predetermined axis of rotation of said tool,

(e) means for shifting the axis of relative swing of said tool and work holder angularly and rectilinearly in a direction radial of the axis of angular shift in a plane perpendicular to the axis of relative swing,

(f) means for producing signals representative of a predetermined coordinate location of said axis of relative swing,

(g) means for'energizing said means for shifting said axis of relative swing in accordance with said signals to move said axis of relative swing to said predetermined coordinate location, and

(h) means for swinging said work holder and tool relatively when the axis of relative swing thereof is in said predetermined coordinate location to move said workholder in an arcuate path past said annular cutting surface.

12. A toric surface generator comprising:

(a) a tool having an annular cutting surface with fixed dimensions,

(c) a work holder,

(e) a pair of electrical means, each means being presettable relative to a reference position to produce a signal representing a coordinate location of said axis of relative swing,

(f) means for shifting the axis of relative swing of said tool and workholder angularly and radially of the axis of angular shift in a plane perpendicular to the axis of relative swing in response to the signals produced by said electrical means, and

(g) means for offsetting the reference position of one of said electrical means a predetermined amount scaled in accordance with the presetting of the other electrical means to modify the signal output from said one electrical means to partially compensate for an elliptical error resulting from the fixed dimension of said cutting tool annular surface.

13. A toric surface generator comprising:

(a) a tool having an annular cutting surface,

(c) a work slide,

((1) means for supporting said tool and work holder adjacent to one another and for relatively swinging said tool and work slide about an axis perpendicular to the predetermined axis of rotation of said tool,

(e) means for shifting the axis of relative swinging of said tool and work holder in coordinate directions angularly and radially of the axis of angular shift in a plane perpendicular to the axis of relative swing,

(g) means for energizing said means for shifting said axis of relative swing in accordance with said signals to move said axis of relative swing to said predetermined coordinate location,

(h) means for holding a workpiece on said work slide to swing against said annular cutting surface when said work slide is swung about the axis of rotation thereof,

(i) means for adjusting the depth of penetration of said annular cutting surface into the workpiece on said work slide, and

(j) means for swinging said workslide and tool relatively when the axis of relative swing thereof is in said predetermined coordinate location to move the workpiece held thereon in an arcuate path of contact with said annular cutting surface.

14. A toric surface generator comprising:

(a) a tool having an annular cutting surface,

(c) a work holder,

(d) means for supporting said tool and work holder adjacent to one another and for relatively swinging 19 said tool and work holder about an axis perpendicular to the predetermined axis of rotation of said tool,

(e) a presettable base curve store adapted to record base curve data,

(f) a presettable cross curve store adapted to record cross curve data,

(g) means responsive to said base curve store for shifting the axis of relative rotation of said tool and work holder to a predetermined position along the axis of rotation of said tool corresponding to the data recorded in said base curve store, and

(h) means responsive to said cross curve store for shifting the axis of relative rotation of said tool and work holder angularly about an axis parallel to the axis of relative rotation of said tool and work holder to a predetermined position laterally offset from the axis of rotation of said tool and corresponding to the data recorded in said cross curve store.

15. A toric surface generator comprising:

(a) a tool having a cutting surface with a fixed annular shape,

(c) a work holder,

((1) means for supporting said tool and work holder adjacent to one another and for relatively swinging said tool and work holder about an axis perpendicular to the predetermined axis of rotation of said tool,

(6) a base curve store having a dial presettable relative to a reference position to record base curve data,

(f) a cross curve store having a dial presettable relative to a reference position to record cross curve data,

(g) means for offsetting the reference position of said cross curve store dial in accordance with the presetting of the base curve store dial to compensate for an elliptical error resulting from the fixed annular shape of the cutting tool,

(h) means responsive to said base curve store for shifting the axis of relative rotation of said tool and work holder rectilinearly to a predetermined position along the axis of rotation of said tool corresponding to the data recorded in said base curve store, and

(i) means responsive to said cross curve store for shifting the axis of relative rotation of said tool and work holder angularly to a predetermined location laterally offset from the axis of rotation of said tool and corresponding to the data recorded in said cross curve store.

16. A toric surface geenrator comprising:

(a) a tool having an annular cutting surface,

(b) a work holder,

(c) means for supporting said tool for rotation on a predetermined aXis and adjacent to said work holder,

(d) means for supporting said work holder including (1) a trunnion and (2) a compound slide mechanism supporting said trunnion for rotation on an axis perpendicular to the predetermined axis of rotation of said tool,

(e) a presettable base curve store adapted to record base curve data,

(f) a presettable cross curve store adapted to record cross curve data,

(g) a pair of motors, each motor operatively connected to said compound slide mechanism,

(h) a first control circuit responsive to said base curve store to operate one of said motors to move said trunnion along the axis of rotation of said tool to a position corresponding to data recorded in said base curve store,

(i) a second control circuit responsive to said cross curve store to operate the other of said motors to move said trunnion in a direction transverse to the 20 axis of rotation of said tool to a position corresponding to data recorded in said cross curve store, and (j) means for holding said tool and work holder in a fixed relative position when said one motor is operated to move said trunnion along the axis of rotation of said tool. 17. A toric surface generator comprising: (a) a base,

(b) a tool having an annular cutting surface,

(d) a work slide,

(f) a presettable base curve store adapted to record base curve data and produce an output signal proportional thereto,

(g) a presettable cross curve store adapted to record base curve data and produce an output signal proportional thereto,

(h) means for shifting said work slide angularly in a plane perpendicular to the, axis of rotation thereof in response to said signal from said cross curve store to move said work slide axis of rotation in an arcuate path having a predetermined radius to a corresponding lateral position relative to the axis of tool rotation,

(i) means for adjusting the predetermined radius of the arcuate path of the axis of rotation of said work slide to a magnitude corresponding to said signal from the base curve store and in response thereto,

(j) means for holding said work slide fixed relative to said base while the adjustment of said radius is being effected, and

(k) means for holding a workpiece on said work slide to contact said annular cutting surface and to swing thereagainst when said work slide is swung about the axis of rotation thereof.

18. A generator for producing a toric surface having selected base and cross curve characteristics comprising:

(a) a base,

(b) a tool having an annular cutting surface,

(d) an intermediate member,

(f) a work slide,

(h) a base curve store adapted to produce an output signal representative of the selected base curve,

(i) a cross curve store adapted to produce an output signal representative of the selected cross curve, (j) means for linearly positioning the axis of angular movement of said work slide at a distance from the axis of swing of said intermediate member corresponding to said signal from the base curve store,

(k) means for maintaining said work slide in a fixed position relative to said base when said axis of angular movement of said work slide is moved,

(1) means for swinging said intermediate member to an angular position on said base corresponding to said signal from the cross curve store, and

(m) means for moving said work slide about the axis of angular movement thereof when said intermediate member is angularly positioned and said axis of angular movement of the work slide is linearly positioned.

19. A toric surface generator comprising:

(a) a base,

(b) a tool having an annular cutting surface,

((1) a work slide,

(e) an intermediate slide,

(f) means for connecting said work slide onto said intermediate slide to rotate on an axis therein perpendicular to the axis of rotation of said tool and for transverse movement relative to said axis of work slide rotation,

(h) means for producing electrical signals representative of a predetermined coordinate location of said axis of work slide rotation,

(i) means for shifting said intermediate slide transversely on said base to a location corresponding to one of said electrical signals,

(j) means for holding said Work slide in a fixed position relative to said base when said intermediate slide is shifted transversely on said base to efifect a corresponding transverse shift of said axis of work slide rotation relative to said work slide,

(k) means for angularly swinging said intermediate slide on said base to an angular position corresponding to another of said electrical signals to position said axis of Work slide rotation around the fixed axis of intermediate slide rotation, and

(1) means for swinging said work slide on said axis of rotation thereof in said intermediate slide for movement in an arcuate path past said annular cutting surface after said axis of work slide rotation is positioned in said predetermined coordinate location.

20. A toric surface generator comp-rising a base,

a tool having an annular cutting surface,

means for supporting and rotating said tool on an axis fixed relative to said base,

a work holder,

a first rectilinearly movable slide on which the work holder is mounted,

a support member on which said slide is movable,

a second rectilinearly movable slide on which said support member is adjustable angularly about an axis perpendicular to the axis of the tool,

a second support member on which said second slide is movable, said second support member being adjustable on the base angularly about an axis parallel to the axis of adjustment of the first support member,

separate motors for rotating said first and second support members and for reciprocating said first and second slide, respectively,

means for holding said first slide in a fixed position relative to said base when said second slide is adjusted, and

means for controlling the movements of said second slide and second support member comprising a manually presettable control for producing an output signal controlling the operation of the motor for driving said second support member,

a manually presettable control for producing an output signal controlling the operation of the motor for driving said second slide, and

signal producing means connected to said second support member and to said second slide, respectively, for producing feedback signals upon movement of said second support and said second slide, respectively, and means for comparing the signals produced by the last-named signal-producing means with the signals produced by the two presetlable controls, respectively, to determine precisely the positions of said second support means and said second slide, respectively.

References Cited UNITED STATES PATENTS HAROLD D. WHlTEHEAD, Primary Examinerx