US2070733A

US2070733A - Lens grinding and polishing machine

Info

Publication number: US2070733A
Application number: US84835A
Authority: US
Inventors: Lowell L Houchin
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-06-12
Filing date: 1936-06-12
Publication date: 1937-02-16
Anticipated expiration: 1954-02-16

Description

Feb. 16, 1937. L. 1.. HOUCHIN LENS GRINDING AND POLISHING MACHINE Filed June 12, 1936 4 Sheets-Sheet 1 INVENTOR. Lowe Houcfim.

A TTORNEYS.

Feb. 16, 1937. 1.. HOUCHIN LENS GRINDING AND POLISHING MACHINE Filed June 12, 1936 4 Sheets-Sheet 2 LOWe// L How/7m.

A TTORNEYS.

Feb. 16, 1937. L. HOUCHIN LENS GRINDING AND POLISHING MACHINE Filed June 12, 1936 4 Sheets-Sheet 3 .0 R m s 0U Y m m E m W w w y YM B 0 0 M I 5 Feb. 16, 1937. HOUcHlN 2,070,733

LENS GRINDING AND POLISHING MACHINE Filed June 12, 1936 4 Sheets-Sheet 4 IN V EN TOR. Lon e L f/ouc/lm.

A TTORNEYS.

Patented Feb. 16, 1937 UNETED STATES PATENT oFFIcE 11 Claims.

My invention relates to a lens grinding and polishing machine. It has to do, more particularly, with a machine for grinding and polishing lenses which is provided with a lens holder and a lap holder movable relative to each other, means being provided for simultaneously moving one of the elements both transversely and longitudinally relative to the other and additional means being provided for imparting a third movement so as to. constantly change the path of movement and the extent of movement of one element relative to the other.

There have been a number of machines of the general type indicated above devised in the past. These machines usually embody a lap holder and a lens holder movable relative to each other. In order that the entire surface of the lens will be abraded by the lap, means is provided for moving one of the elements, usually the lens, relative to the other both transversely and longitudinally at the same time. However, in order to break up the lines of abrading and to reduce the chances of having inaccuracies in the finished lens, a third motion is usually employed. The third motion is accomplished by having additional means for moving the elements relative to each other so as to change the paths of travel of the movable elements during successive strokes and cycles of movement.

Although these prior art machines of the general type indicated have gone into extensive use, they are possessed of certain undesirable fea tures. One of the greatest disadvantages of these prior art machines resides in the fact that they are of a complicated structure and, therefore, are expensive to construct and maintain. They are usually provided with a number of parts which do not wear for any appreciable length of time. Another great disadvantage of such prior art machines resides in the fact that they are so constructed that the third motion provided for breaking up the lines of grinding does not break up the lines sufficiently or as often as would be desirable. These prior art machines have been possessed of other undesirable features.

One of the objects of my invention is to provide a lens grinding and polishing machine which is provided with a lens holder and a lap holder, means being provided for simultaneously moving such elements relative to each other in two directions at right angles to each other, and additional means being provided for imparting a third movement to such elements so as to constantly change the path of movement and the extent of movement of one element relative to the other in order to break up the lines of grinding to a greater extent and more often thanwith prior art machines and thereby obtain a more accurate surface on the lens.

Another object of my invention is to provide a machine of the type indicated which is of a very simple structure and is therefore inexpensive to construct and maintain and which is provided with a minimum number of parts which are subject to wear.

Another object of my invention is to provide a machine of the type indicated provided with means for bringing about three movements of the lens and lens-grinding lap relative to each other, such means being of such a nature that the three movements are independent of each other and, consequently, such movements may be controlled in such a manner that maximum breaking up of the lines of grinding will be obtained.

In its preferred form, my invention contemplates the provision of' a machine embodying a base or housing having a frame disposed therewithin for movement longitudinally thereof. This frame has a portion extending through the forward wall of the housing and this portion carries a table upon which a plurality of laps may be mounted. I provide means for reciprocating the frame longitudinally of the housing and this means is adjustable at will to vary the extent of the longitudinal movement of the lap table which is carried by this frame. A second frame is disposed within the housing and has a plurality of forwardly projecting arms which carry lens-holding members adjacent their forward ends. These lens-holding members are so arranged that the lenses will contact with the surface of the laps which are disposed adjacent the forward wall of the housing. The frame that carries the lens-holding members is so constructed and supported that it may be rocked transversely of the housing so that the lenses will be reciprocated transversely relative to the laps. I provide means which is adjustable at will to change the extent of this transverse movement. Thus, it will be understood that the transverse movement of the frame that carries the lensholding members and the longitudinal movement of the frame that carries the laps, which occur simultaneously, produces both transverse and longitudinal movement of the lenses relative to the laps. I also provide additional means for obtaining a third movement of the lenses relative to the laps so as to break up the lines of grinding. This means preferably comprises mechanism for imparting an additional transverse movement to the frame that carries the lens-holding mem-.

bers in order to constantly change the extent and the path of the transverse movement of the lenses relative to the laps. This machine is of such a type that the three movements are independent of each other and the speed of each movement may be selected so that maximum breaking up of the' lines of grinding will be accomplished.

The preferred embodiment of my invention is illustrated in the accompanying drawings wherein similar characters of reference designate corresponding parts and wherein:

Figure 1 is a perspective view of a complete machine made in accordance with the principles of myinvention.

Figure 2 is a view, mainly in section, showing the mechanism which normally maintains a lens in contact with a lap.

Figure 3 is a plan View of the machine with the top of the housing removed, showing the operating mechanism thereof.

Figure 4 is a view mainly in side elevation, the side of the housing being removed to show the operating mechanism. 7

Figure 5 is a perspective view showing the op erating mechanism of the machine.

Figure 6 is an end view of a bearing for supporting the frame that carries the lap tables.

' Figure '7 is a side view of the same bearing.

Figure 8 is a view, mainly in section, of a different bearing structure used in supporting the frame that carries the lap tables.

Figure 9 is a view partly in section and partly in perspective illustrating the lap tables and supporting structure.

Figure 10 is a perspective view of a lap which I preferably use on my machine.

Figure 11 is a section showing an eccentric ,for controlling! longitudinal movement of the frame that carries the lap tables.

- Figure 12 is a section of an eccentric that con-' trols transverse movement of the frame that carries the lens-holding members.

Figure 13 is a frontview of the lap tables and supporting structure illustrating how this structure may be vertically or longitudinally adjusted.

Figure 14 is a diagram illustrating the path of movement of a point on a lens relative to the lens-grinding lapwith which it contacts.

- Figure 15 is a similar view illustrating the path of movement of the point on the lens relative to the lens-grinding lap after the machine has been adjusted to obtain a greater transverse movement than that illustrated in Figure 14.

With reference to the drawings, and particularly to Figure 1, my machine is shown as comprising a housing I which is preferably of substantially box-like form and is preferably made of metal. This housing preferably has a hinged door. 2 at its top which is provided so that the operating mechanism of the machine may be reached for adjustment and other purposes.

Lap-carrier In the machine'illustrated I provide means for carrying two laps although it will be apparent that the machine may be modified to carry a single lap or any number of laps. I will first describe the structure which I provide for carrying the laps in such a manner that they may be reciprocated longitudinally of the housing.

This structure is illustrated best in Figure 5. As shown, it comprises two supporting blocks 3 which are integrally secured to a plate 3a,'which is secured to the bottom of the housing, and these blocks are disposed at the ends of the plate. These blocks are located adjacent the forward wall of the housing and adjacent the ends of the housing. At the rear ends of these blocks a longitudinally extending rod 4 is supported in spaced relation to the plate 3a. This rod will not move longitudinally. At the forward end of each of the blocks 3 is disposed a bearing housing 5. These bearing housings 5 contain bearings which support a longitudinally extending shaft 6 which is. supported in such a manner that it may be reciproto support the lap table. This member 8 has a' sleeve 9 formed thereon through which the shaft 8 extends. The member 8 is supported on the shaft in such a manner that it will not move longitudinally thereof. This member 8 extends forwardly through an opening or slot [0 formed in the forward wall of the housing as illustrated in Figure 4. The extreme forward edge of the member 8 has an upstanding support H formed thereon. This portion II is disposed outside of the housing and adjacent the forward wall thereof. It is provided with a pair of vertically extending open-ended slots l2.

The member 8 extends rearwardly to a point adjacent the rod 4. This member 8 at its extreme rear end carries a. bearing structure it which is provided for supporting the rear end of member 8 on therod 4 in such a manner that the member 8 may be moved longitudinally of the rod. The bearing structure 53 is illustrated best in Figure 8. It comprises a pair of grooved rollers I which are rotatably mounted, one of the rollers being disposed in front of the rod d and the other behind. Beneath the rod :3 a third roller (5 is rotatably mounted. This roller 15 has a flat surface which engages a flat surface it formed on the lower side of the rod 4. Thus it will be apparent'that this bearing structure will support the rear end of the member 8 on the rod 4 so that it may be moved longitudinally along the rod with a minimum of friction. The member 8 will be supported in such a manner that friction will be reduced to a minimum. The roller I5 will take the thrust caused by the weight on the extreme forward end of the member 8. The rollers I4 and the rollers I guide the movement of this structure and are so arranged that the member 8 may be moved longitudinally without vibration and with a minimum amount of friction.

Thus, it will be apparent that the member 8 may be moved longitudinally of the housing. The means for moving this member longitudinally of the housing will be described in detail hereinafter.

V The Zap tables and supporting structure The lap tablesand supporting structure are this support I! on the support H at the extremeforward end of the member 8. The bolts l9 will extend through the slots l8 in member H and through the slots l2 in the member I I. Thus, it will be apparent that themember' I! will be adjustably supported on the member I I. The member I! may be moved vertically or laterally relative to the member H (Figure 13) when bolts l9 are loosened, so that the member l1 may be properly positioned to properly locate the lap tables, and may be held in adjusted position merely by tightening the bolts IS.

The lap L which I preferably use on the machine is illustrated in Figure 10. It comprises a body portion having a flat lower surfacein which a notch 2i! is formed. The member I! supports a pair of lap tables 2| which project forwardly therefrom. The upper surface of each of these tables is substantially fiat but has a depression 22 formed therein in such a manner that an upstanding lug 23 is produced. This depression is formed mainly for the purpose of allowing the lap to rest on the outer edges only of the table in order to insure firm contact which will prevent rocking of the lap. The lug 23 projects above the surface of the table upon which the lap L will rest and is indicated best in Figure 4. The lug 23 will project into the notch 20 in the lower surface of lap L. The notch is just slightly wider than the diameter of the lug 23 so. that when the lug projects thereinto, the notch and lug will cooperate to prevent longitudinal movement of the lap on the table. However, because the notch is elongated, as indicated, transverse movement of the lap on the table will be permitted.

I provide means for clamping the lap in position in order to normally prevent movement of the lap on the table. This means comprises a lug 24 with a straight forward edge arranged so that the rear edge of the lap will contact therewith and a clamping member 25 adapted to contact with the forward edge of the lap so that it will be firmly gripped between the clamping member 25 and the lug 24. The clamping member 25 is pivoted at its lower end as at 26 between a pair of ears 2! formed on the lower and forward portion of the table 2i. The upper end of the clamping member 25 has a rearwardly projecting finger 28 adapted to engage the forward edge of the lap L as indicated in Figures 4 and 9. A screw 29 passes through the clamping member 23 intermediate its ends and is threaded into a bushing 33 disposed in an opening in the lap table 2!. The screw is free to rotate in the opening in the member 25 through which it extends. The outer end of the screw is enlarged to form a handle portion 31, the inner end of which engages the clamping member 25.

It will be apparent that in using this clamping device, the lap L is placed on the table with the notch 29 over the lug 23. Since the notch is of substantially the same width as the diameter of lug 23, longitudinal movement of the lap on the table will be precluded. The handle 3! of the screw may be turned until the finger 28 touches the forward edge of the lap L and forces the lap transversely of the table into firm contact with the lug 23. The lap will be tightly gripped between finger 28 and lug 24. The notch 23 and the cooperating lug 23 serve to initially properly position the lap longitudinally of the table 21 and the clamping means serves to position it properly transversely of the table.

I provide means for effectively lubricating each of the screws 29 in order to prevent binding thereof. It will be apparent that the moisture from the abrasive, which is usually in the form of a paste, would tend to rust the screws 29. How ever, I provide means for effectively lubricating the screws and thus eliminating any possibility of their rusting and binding.

This lubricating means comprises a reservoir 32 mounted on the member I! intermediate the two lap tables 2|. This member 32 has a cap 33 on, its upper end which may be opened to permit filling with a lubricant. The lower end of the reservoir 32 is open and communicates with a vertical passageway 33a which in turn communicates with a horizontally extending passageway 34. The passageway 34 extends from the bore in which one of the screws 29 is disposed to the bore where the other screw is disposed. Thus, the lubricant is fed to the rear end of each of the screws 29. It will be noted that the screws are downwardly and forwardly inclined. Consequently, the lubricant will flow downwardly and forwardly along the entire length of the screws. Thus, the screws will be lubricated throughout their lengths.

The depression 22 in the lap tables will tend to collect any moisture which might seep beneath the laps and, therefore, will prevent sticking of the laps on the lap tables because of rust. The bottom of the housing i extends forwardly as indicated in Figures 1, 3 and 4 to form a shelf la which will catch any abrasive that falls off the laps.

To prevent any abrasive from reaching the operating mechanism of the machine I provide a guard member 35 which is secured to the rear edge of the member I! as at 3B (Figure 4). The rear edge of this guard projects into a slot 31 formed in the forward wall of the housing. The guard 35 will move longitudinally with the lap tables and the rear edge will reciprocate in the slot 31. This guard will prevent abrasive from reaching the opening 20 through which the member 8 projects. However, it will be noted that the edges of the opening H] are inclined downwardly as indicated at 38 so that if any abrasive reaches this opening, there will be a tendency for it to drop forwardly rather than rearwardly through the opening.

Lens-carrier In this machine, I provide means for carrying two lenses although it will be apparent that the machine may be modified to carry any number of lenses and a corresponding number of laps. I will now describe the means which I provide for carrying the lenses in order that they may be moved transversely substantially at right angles to the movement of the laps.

The structure which carries the lens-holding members comprises a frame indicated generally by the numeral 39 which is mounted for rocking movement transversely of the housing. This frame 33 has a pair of depending legs 43 which are spaced longitudinally so that each of the legs 40 lies adjacent one of the blocks 3. The lower end of each of the legs 43 is pivotally mounted on a shaft 4| as at 42, there being a roller bearing disposed at this point to prevent wear. The shaft 4! extends longitudinally parallel to the shaft 6. Each end of the shaft is provided with a crank arm 43 which has one end keyed to the end of shaft 4| and has a pin 64 keyed to the other end which projects into an anti-friction bearing, such as a ball bearing disposed in a bearing support 45 which is mounted on the block 3. Thus, it will be apparent that an eccentric structure is provided at each end of the shaft 4|. I will designate each of these eccentric structures generally by the numeral 46. It will be apparent that when these eccentrics 46 are rotated, the lower ends of the legs 49 will be moved both forwardly and rearwardly and upwardly and'downwardly. In other words, thelegs 45 will move in vertical planes in a rotary path.

The frame 39 has a longitudinally extending portion 4'1 which connects the upper ends of the leg 48 together. a rearwardly extending Y-shaped portion 48. The rear end of this Y-shaped portion 48 is curved downwardly as at 49 and this curved portion is bifurcated. The extreme end of this portion 49 is connected to the lower end of a. link 59a by a ball bearing pivotal connection. The upper end of the link 5511 is connected to an eccentric structure illustrated generally by the reference character 50. This eccentric 50 is illustrated best in Figure 12. which is integrally formed with a shaft 52 that is mounted for rotation on supports 53a disposed adjacent the rear end of the housing. This member 52 is provided with a T slot 53 into which the headed end of a bolt 54 projects. This bolt 54 passes through an anti-friction self-aligning bearing structure 55 and is held in position by a nut 55 and a lock-nut 56a. The upper end of link 59a has a collar 51 which fits around the bearing 55. Thus, I provide means for pivotally connecting the rear end of member 48 to the eccentric structure 59. When this eccentric structure is rotated the frame 39 will be rocked about the pivot points 42.

Thus, the eccentric 50 will produce a transverse rocking movement of the frame 39. The coaxially arranged eccentrics 46 will produce a different and independent transverse rocking movement of the frame. The extent of the movement produced by the eccentric 50 may be varied by changing the position of the bolt 54 in the slot 53 in disk 5|. This bolt may be moved into alignment with the shaft 52 so that the eccentric 56 will be ineffective or may be moved outwardly to obtain movement of any desired extent. It may be held in adjusted position by tightening the nut 56 and lock nut 56a.

The frame 39 has a pair of arms 59 pivotally mounted thereon in such a manner that the arms may rock both longitudinally and transversely of the machine. These arms are adapted to carry lens-holding members. In order to mount these arms on the frame 39, the horizontal portion 41 of this frame is provided adjacent each end with a pair of upstanding supports which carry bearing housings 60. These bearing housings 69 have roller bearings disposed therein and receive stub shafts 6! (Figure 3) which project thereinto and which are integrally secured toa substantially rectangular member 62. The member 62 has a second set of stub shafts which project into ball bearings disposed in housings 63 (Figure 4) formed on the lower ends of depending portions 5 formed on the rear end of the member 59. The axes of the bearings in the housings 60 are disposed at right angles to the axes of the bearings in the housings 63. Thus, it will be apparent that each of the arms 59 will be free to rock about its axis and will also be free to swing in a vertical plane about the pivot points Bi.

The lens-carrying arms 59 project forwardly through slots 65 formed in the forward wall of the Connected to this portion 41 is n It comprises a disk-like member 5| housing. The portionof each arm 59 that extends out of'the housing is provided with a member 65 for carrying a lens'block. This member 55 may be of any suitable type but preferably embodies a member having a pair of depending pins 6'! that project into sockets formed in the upper surface of a block 58 to which is cemented or otherwise secured a lens L. The pins 61 will permit movement of thelens andthe lap relative to each other in both directions but will prevent rotation of thelens relative to the lap. Consequently, this will insure that the curvature of the lap will be imparted to the surface of the lens.

7 Means for maintaining the lap and Zens'm contact The means for maintaining the lap and lens in contact with each other firmly but resiliently is indicated best in Figures 1, 2 and 5. As illustrated, the forward portion of each arm 59 is downwardly turned as at 55 and then has a forwardly extending portion 19. is at a level substantially corresponding with the level where the lens L and the lap L contact with each other. upper surface which receives a point H formed on the extreme lower end of a rod 12. '52 extends upwardly and has its upper end slidably mounted in a sleeve or collar l3 on the outer end of a pivoted arm 54. A compression spring 15 surrounds the rod 52 and the upper end of this spring abuts a washer i6 disposedwithin the collar 13. The lower end of this spring bears against an enlargement H formed on 'therod E2 adjacent its lower end. Thus, it will be apparent that the spring l2 will function to force the forward end of the arm 59, that carries the lens, downwardly so that the lens will be in firm but resilient contact with the lap.

The arm i4 is pivoted at its rear end as at 18 to an upstanding support 79 which has its lower end rigidly mounted between a pair of upstanding lugs 85 formed on the top of the housing. When the lap and the lens are in contact with each other, the arm id will be in substantially the position illustrated in Figure 4. I provide latch mechanism for maintaining the arm 14 in operative position but which may be quickly operated in order to release the arm 14 to permit This portion 19 This portion Hi has a cup in its This rod The latch for controlling the movement of arm i4 is illustrated best in Figure 2. As shown,

this arm 14 is of hollow construction. It is pivoted to the member it? as at E8 as previously indicated. The upper end of the member 19 has an arcuate shaped ratchet portion 84 formed on the forward edge thereof. formed in its extreme upper end in which is disposed a compression spring 86. The upper end of this compression spring bears against the arm 14 as at 81', lugs being provided for preventing displacement of the end of the spring. It will be apparent that this spring 85 will normally tend to swing the arm 74 upwardly about the pivot point it.

A latch 83 is provided for cooperation with the ratchet 84 and is carried by the arm "M. The rear end of this latch 88 passes between guide It also has a socket 85' pins 89 disposed on the arm I4. The forward end of this latch 89 is pivoted to a trigger 90 as at 9|, the trigger being pivoted to the arm "14 as at 92. A compression spring 94 has its upper end disposed in a socket 95 formed in the arm 14 and its lower end in a socket formed in the upper surface of the trigger 90. The compression spring 94 normally tends to pivot the trigger 90' rearwardly about the pivot point SI and force the latch 83 rearwardly into cooperative relation with the ratchet 84. However, it will be apparent that if the trigger 90 is pulled forwardly, the latch 08 will be withdrawn from the ratchet and upward swinging movement of the arm 14 will be permitted, this upward move ment being produced by the spring 30 which will cause the arm I I to pivot about the point I8.

It will be apparent that this latch mechanism is disposed substantially entirely within the arm M. This latch mechanism will be automatically operative to hold the arm I4 in any position when it is swung downwardly. The spring 94 will tend to always maintain the latch 88 in contact with the ratchet. The compressive force exerted by the compression spring 15 will depend upon the extent to which the arm id is swung downwardly. This force may be varied merely by pressing downwardly on the outer end of the arm Id to cause it to swing further downwardly, the latch mechanism automatically looking it in position. To facilitate operation of the latch mechanism by means of the trigger 90 a hand grip 98 is provided on the forward end of the arm I4 in order that the trigger and the portion 99 may be gripped simultaneously.

When the machine is not in use, as indicated in Figure l, the latch mechanism will be released in order to permit automatic upward swinging of the arm 74 and, consequently, upward swinging of the arm 59 so that the lens may be removed. When the machine is to be used again the lens is positioned on the lap and the arm I4 is swung downwardly which will cause the arm 59 to be moved downwardly, the spring 15 exerting sufiicient force against the forward end of the arm 59 to hold the lap and the lens firmly but resiliently in contact. As previously stated, the force exerted by the spring 75 will depend upon the extent to which the forward end of the arm 74 is swung downwardly.

The fact that the point of application of the downward force by means of the rod 12 and spring 15 is substantially at the level of the point of contact of the lens and the lap makes it possible to grind strong plus lenses on the machine. A downward pull will be exerted on the lens rather than a downward thrust and this will make it possible to grind stronger plus lenses without danger of error.

In order to prevent any abrasive which might pass through the openings 05 from reaching the operating mechanism of the machine I provide a downwardly inclined guard member 9'! which has its upper edge secured to the forward wall of the housing and has its lower edge 98 upwardly turned. A similar guard 99 is secured to the frame 39 and extends in overlapping relationship to the guard 91. This guard 99 is downwardly and forwardly curved. It is of such width that it will always overlap the guard 91 regardless of the position of the frame 39.

Longitudinal movement As previously stated, the structure which carries the arms 59, that carry the laps, is free to move longitudinally of the machine and such movement will cause longitudinal movement of the laps relative to the lenses. The means for accomplishing this longitudinal movement is indicated best in Figures 3, 5 and 11.

This means comprises a longitudinally extending pitman I which is pivotally connected as at IOI to an upstanding member I02 disposed substantially midway between the forward and rear ends of the member 8. A ball bearing is preferably disposed at this pivot point. The other end of the pitman I00 is pivotally connected to a shaft E03, which is supported in a self-aligning ball bearing on the upper end of a support I04, by means of an eccentric indicated generally by the numeral I05.

The eccentric I is illustrated best in Figure 11. This eccentric comprises a disk I06 disposed e-ccentrically on the forward end of the shaft I03 and keyed thereon. A disklike member I01 is mounted on the member I06 and is free to rotate thereon being provided with a peripheral flange I08 that surrounds the member I06. This member I01 has a pivot pin I09 eccentrically disposed thereon which carries a self-aligning ball bearing structure III. Nuts IIO are threaded on the outer end of pin I09 to hold the bearing thereon. The end of the pitman has a collar II2 which surrounds this ball bearing structure. The disk I06 has a groove H3 in its periphery. Three members II4 project through the flange I08 of member I0! into the groove H3 and member I06. One of these members is an adjustable setscrew.

The shaft I03 and the pin I09 are usually out of alignment with each other. Consequently, when the shaft I03 is rotated, the member 8 will be moved longitudinally of the machine by means of the eccentric structure I05 and the pitman I00. The extent of the longitudinal movement may be varied by adjusting members I09 and I0! relative to each other. To do this the setscrew H4 is loosened and then the member ID! is rotated relative to the member I06. This will vary the position of the shaft I03 and the pin I09 relative to each other. Consequently, this will vary the extent of the lengthwise movement of the pitman I00. The shaft I03 and the pin I09 are so arranged that they may be brought into alignment if desired, so that there will be no lengthwise movement of the pitman I00 and, consequently, no longitudinal movement of the member 8.

Transverse movement As previously stated, the frame which carries the arms 59, that carry the lenses, is free to rock transversely of the machine and such rocking movement will cause transverse movement of the lenses relative to the laps. The means for accomplishing this transverse movement is illustrated best in Figures 5 and 12. As previously stated, this mechanism comprises the eccentric illustrated generally by the reference character 50 and the link 50a which pivotally connect the portion 49 of member 48 to the shaft 52.

When the shaft 52 is rotated, the eccentric 50 will rock the frame 39 about the pivot points 42. Consequently, due to this transverse rocking movement of the frame, the lenses will be caused to move transversely relative to the laps. The extent of the transverse movement will depend upon the position of the pivot bolt 54 relative to the center of the disk 5| and this may be varied whenever desired.

Third movement The means for accomplishing the third movement of the lap and lens relative to each other in order to break up the lines of grinding has been previously described. This means comprises the eccentric 46 which causes the frame 39 to move in a rotary path transversely of the machine. The longitudinal movement, the transverse movement, and the third movement, which also might be said to be a transverse movement, all occur simultaneously, as will be brought out more in detail hereinafter. All of thesemovements are independent of each other and the speed of each movement may be controlled independently of the speed of the others.

The third movement'which breaks up the line of grinding and which is'accomplished by means of the eccentric 46 will constantly vary the extent of the transverse movement produced by the eccentric 59. This is due to the fact that as the eccentric 59 causes the frame 39 to rock about the pivot point 42, the eccentrics 46 also rotate and cause the entire frame to'move bodily forwardly and rearwardly. Thus, the extent of transverse movement produced by the eccentric 50 is constantly varied.

. wall thereof.

The eccentrics 46 are rotated by means of a pulley H5 which is keyed to one of the stub shafts44 that is secured to a crank arm 43, the stub shaft extending through the bearing in the support 45. When thepulley H5 is rotated, the eccentrics 46 are rotated, both of them being rotated simultaneously because they are connected together by the shaft 4|.

' The driving means The driving means of the various parts of the machine is illustrated best in Figures 3, 4 and 5. For driving these various parts of the machine I provide electric motor II6.; This motor H6 is supported within the housing adjacent the rear This motor. may be controlled by means of a switch operated by a lever H1 (Figure 3) which extends through aslot H8'formed in one of the side walls of the housing. Motor H6 is provided with a drive shaft H9. This shaft has a pulley I keyed thereon which drives the pulley H5, which controls rotation of eccentrics 46, by means of a belt I2I. The pulley I29 and the pulley H5 are of substantially the same size so that the two eccentrics 46 will be driven at substantially the same speed as the drive shaft of the motor.

The drive shaft H9 has a second pulley I22 keyed thereon which is smaller than the pulley I20. This pulley I22 drives a'larger pulley I23 by means of a belt I24. The pulley I23 is keyed on the end of shaft 52 which drives the eccentric 59 provided for obtaining the transverse movement of the frame 39. It will be apparent that the eccentrics 46 will be driven faster than the eccentric 50. Consequently, the transverse movement accomplished by means of eccentric 50 will be slower than the third motion accomplished with the eccentrics 46. This results in the path of movement of the lens transversely of the lap, produced by eccentric 50, being changed several times, by means of eccentrics 46, during a single movement of the lens transversely of the lap from one edge thereof to the other. This insures that the lines of grinding will be broken up often and to a sufficient extent. The drive shaft of the motor projects through the side wall of the housing and on its outer end has a hand wheel I keyed thereto. This hand wheel I25 is provided so that the drive shaft I I 9 may be rotated marlually when the motor H6 is not running. Thismay be desirableto properly adjust the machine before operation thereof is started.

The drive shaft H9 of the motor also projects from the opposite side thereof. It drives a gear reduction unit I26. This gear reduction unit I26 is connected to the shaft I93 that drives the eccentric 65 which produces the longitudinal movementof the structure that carries the lap table. that the shaft Hi5 will be driven at a slower rate than the drive shaft. Thus, the longitudinal movement will also be at a slower rate than the third movement which is produced by means of the eccentrics 46. l

The operation In operation of the machine, the laps L are first mounted'on the lap tables in the manner described. The lens blocks carrying the lenses are disposed in cooperative relationwith the lap and the arms 59 are then lowered into operative position where the spring 15 will exert a downward force, causing the lenses to firmly contact with the laps. The arms 59 may be moved into operative position merely by swinging the arms 14 downwardly, the latch mechanism carried by the arms l4 serving to automatically lock these arms in operative position in order that the spring l5 will force the lenses in firm contact with the lap. The motor H6 may then be started by means of the switch lever Ill. This will cause the driving mechanism to function.

The eccentric I95 will be driven and will cause reciprocation cf the pitman I66. This will'in turn cause longitudinal movement of the member 8 which carries the laps. Consequently, the laps will be reciprocated longitudinally relative to the lenses. The laps will move back and forth in a horizontal plane.

At the same time the eccentric I65 is driven, the eccentric 56 is also driven. This causes rocking of the frame 39 about the pivot points 62 and thereby produces transverse movement of the lenses relative to the laps. During this transverse rocking of the frame 39, the arms 59 which carry the lenses will pivot about the pivot points 6i. Because of the longitudinal movement of the laps, the arms 59 will simultaneously pivot about the axes of the bearings in the housings 63. In other words, the arms 59 will rock in a vertical plane and will also rock about their own axes.

Thus, it will be apparent that the lenses and the laps are moved relative to each other simultaneously in two directions substantially at right angles to each other. However, simultaneously with such movements in both directions, a third movement is produced by means of the eccentrics 46 which are driven comparatively fast. These eccentrics produce a back and forth and up and down, in other words a rotary, movement of the frame 39. This causes a constant change in the path of movement of the lens and lap relative to each other since it varies the extent of the transverse movement producedby means of the eccentric 59. at a greater rate of speed than the eccentric 59, the path of movement of the lenses transversely of the laps will be changed several times during a single movement of the lenses transversely of the laps from one edge thereof to the other. This will insure that the lines of grinding will be broken up sufliciently to overcome any chance of error.

The gear reduction unit is provided sov Since the eccentrics 46 are rotated" As previously described, the extent of the longitudinal movement may be varied at will by adjusting the eccentric M5. The extent of the transverse movement may be adjusted at will by adjusting the eccentric 5%. In Figure 14, I illustrate the path of movement of a point on the lens relative to the lap, produced when the lens is mounted on my machine and the machine is operated. Figure is a similar view illustrating the path of movement when the pivot bolt 54 of the eccentric is adjusted farther away from the center in order to obtain a greater transverse movement.

One or" the important features of my invention lies in the fact that the three motions described are independent of each other. Ihus, the speed of each movement may be difierent from the speed of the others. Because of this, it is possible to select speeds in such a manner that the path of movement of the lens and the cooperating lap relative to each other is changed several times during a single stroke.

The fact that the relative longitudinal movement between the laps and the lenses is accomplished by moving the lap tables longitudinally rather than moving the lens-carrying members longitudinally is advantageous. ihe laps will be moved in a horizontal plane and Will not be moved arcuately. This results in smoother operation and less friction than when the longitudinal movement is accomplished by moving the lensholding members longitudinally and because of this, it is possible to grind stronger plus lenses without the usual difficulties.

It will be apparent from the above description that I have provided a machine having many desirable features. The machine is very simple yet very efiective for the purposes for which it is intended. Any of the pivot points or bearing points which might be subject to wear are provided With ball bearings. The machine is so constructed that the third movement provided therein is of such a nature that the lines of grinding are broken up to a greater extent and more often than with prior art machines.

Many other advantages will be apparent from the description and drawings and the following claims.

Having thus described my invention, what I claim is:

1. A lens grinding and polishing machine comprising a lap holder and a lens holder movable relative to each other, means for moving the lap holder in a straight line only in one direction relative to the lens holder, means for moving the lens holder in a straight line only relative to the lap holder in a different direction and at an angle to the line of movement of the lap holder, both of said means operating simultaneously, and means for automatically varying the movement in one direction produced by one of said preceding means,

2. A lens grinding and polishing machine comprising a lap holder and a lens holder movable relative to each other, means for reciprocating the lap holder in a straight line only relative to the lens holder in one direction, means for reciprocating the lens holder in a straight line only relative to the lap holder at an angle to the firstmentioned reciprocation, both of said means operating simultaneously, and additional means for automatically varying the extent of reciprocation produced by one of said preceding means, said last-named means being of such a nature that the path of movement of the lens holder and the lap holder relative to each other is changed several times during a single stroke.

3. A lens grinding and polishing machine comprising a lap holder and a lens holder movable relative to each other, means for moving the lap holder in a straight line only relative to the lens holder in one direction, said means including an eccentric, means for moving the lens holdor in a straight line only relative to the lap holder in a difierent direction at an angle to the line of movement of the lap holder, said means including an eccentric, and means for automatically varying the movement in one direction produced by one of the said preceding means, said lastnamed means including an eccentric.

4. A lens grinding and polishing machine comprising a lap holder and a lens holder movable relative to each other, means for moving the lap holder in a straight line only relative to the l ns holder in one direction, said means including an eccentric, means for moving the lens holder in a straight line only relative to the lap holder in a different direction at an angle to the line of movement of the lap holder, said means including an eccentric, means for automatically varying the movement in one direction produced by one of the said preceding means, said lastnamed means including an eccentric, and means for driving all of said eccentrics in such a manner that the lastnamed eccentric is driven at a higher rate of speed than the second-named eccentric.

5. A lens grinding and polishing machine comprising a lap holder and a lens holder movable relative to each other, means for moving the lap holder in a straight line only relative to the lens holder in one direction, said means including an ecentric, means for moving the lens holder in a straight line only relative to the lap holder in a different direction at an angle to the line of movement of the lap holder, said means including an eccentric, means for automatically varying the extent of movement produced by the means for moving the lens holder, said lastnamed means including an eccentric, and means for driving said eccentrics at different rates of speed.

6. A lens grinding and polishing machine comprising a frame which carries a lap holder, said frame being supported in such a manner that it may be moved longitudinally of the machine in a straight line only, means for moving said frame longitudinally of the machine, a second frame which carries a lens holder, said second frame being supported on the machine in such a manner that it may be rocked transversely thereof in a straight line only at an angle other than a straight angle relative to the line of movement of the first frame, means for rocking the second frame transversely of the machine, means for varying said transverse rocking movement, said means comprising an eccentric which carries said second frame and moves it bodily along the same line of movement produced by said second-named means, said second frame rocking about said eccentric during its transverse movement.

'7. A lens grinding and polishing machine comprising a frame which carries a lap holder, said frame being supported in such a manner that it may be moved longitudinally of the machine in a straight line only, means for moving said frame longitudinally of the machine, said lastnamed means being manually adjustable to vary the extent of the longitudinal movement, a second frame which carries a lens holder, said secnd frame being supported on the machine in such a manner that it may be rocked transversely thereof in a straight line only at an angle other than a straight angle relative to the line of movement of the first frame, means for rocking the second frame transversely of the machine, said means being manually adjustable to vary the extent of the transverse movement, and means for bodily moving the second frame transversely and automatically along the same line ofmovement produced by said second-named means during the transverse movement produced by said secondnamed means, said means comprising an eccentric which supports said frame and about which the frame rocks during its transverse movement.

8. A lens grinding and polishing machine comprising a frame which carries a lap holder, said frame being supported in such a manner that it may be moved longitudinally of the machine in a straight line only, means for moving said frame longitudinally of the machine, said means comprising a rotatable eccentric operatively connected to the frame, a second frame which carries a lens holder, said second frame being supported on the machine in such a manner that it may be rocked transversely thereof in a straight line only at an angle other than a straight angle relative to the line of movement of the first frame, means for-rocking the second frame transversely of the machine, said means comprising an eccentric operatively connected to the secondframe, and means for bodily moving the second frame transversely and automatically along the line of movement produced by said second-namedmeans during the transverse movement'produced by said second-named means, said means comprising a plurality of co-axially arranged eccentrics which,

carry said second frame and about which the frame rocks during its transverse movement.

9. In a lens grinding and polishing machine a lap support, a lens support, one of said supports being pivotally mounted so that it may be swung into and out of operative position relative to the -"other, means for holding said support in operative relation to the other, said means comprising a spring-operated plunger rod which contacts with said support, said plunger rod being mounted on a support which is pivoted for swinging movement in a vertical plane, said plunger rod and said last support being operatively connected in such a manner that as the support is swung downwardly the force exerted by the plunger rod increases, and an automatically operative latch mechanism for locking the support in any position to which it is swung to increase the effect of the plunger rod.

10. In a lens grinding and polishing machine, a lap support, a lens support, one of said supports being pivotally mounted so that it may be swung into and out of operative position relative to the other, means for holding said support in operative relation to the other, said means comprising a spring-operated plunger rod which contacts with said support, said plunger rod being mounted on a support which is pivoted for swinging movement in a vertical plane,,resilient means for normally swinging said support upwardly, said plunger rod and said last support being operatively connected in such a manner'that as the support is swung downwardly the force of the plunger rod increases, automatically operative ratchet and latch mechanism for locking the support in any position to which it is swung to increase the effect of the plunger rod, and manually operative means for releasing the latch and ratchet mechanism to permit said support to be swung upwardly automatically by said resilient means.

11. In a lens grinding and polishing machine, a lap support, a lens support, one of said supports being pivotally mounted so that it may be swung into and out of operative position relative to the other, means for holding said support in operative relation to the other, said means comprising a spring-operated plunger rod which contacts with said support, said plunger rod being mounted on a support which is pivoted on the machine for swinging movement in a vertical plane, resilient means for normally swinging said support upwardly, said plunger rod and said last support being operatively connected in such a manner that as the support is swung downwardly the force exerted by the plunger rod increases, a ratchet rigidly carried by the machine, a latch carried by the support, said latch being springpressed so that it always engages said ratchet, and a trigger for'releasing said latch from said ratchet.

LOWELL L. HOUCHIN.