US2122056A

US2122056A - Lap retruing machine

Info

Publication number: US2122056A
Application number: US89033A
Authority: US
Inventors: Robert S Duke
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-07-06
Filing date: 1936-07-06
Publication date: 1938-06-28
Anticipated expiration: 1955-06-28

Description

June 28, 1938. R. s. DUKE LAP RETRUING'MAGHINE Filed July 6, 1936 3 Sheets-Sheet 2 Juhe 28, 1938. R, a DUKE 2,122,056

LAP RETRUING" MACHINE Filed July 6, 1936 3 Sheets-Sheet 3 Patented June 28, 1938 UNITED STATES PATENT OFFICE This invention relates to a'lap re-truing machine.

It is an object of the invention to provide a machine of the character described and specially designed for reshaping the spherical or toric surface of the lap, such. as are used in lens grinding and polishing machines.

In the manufacture of lenses, such as optical lenses, a grinder is employed, one element of m which comprises a lap having a grinding surface which is of the curve of the desired surface of the lens to be ground. As a result of use the active surface of the lap,be it either convex or concave,

becomes misshapen from wear. It is an object of if this invention to provide a re-truing machine wherein the grinding lap may be restored to itsoriginal curve or curves.

' It is another object of the invention to provide a machine of the character described wherein the 20 misshapen lap may be mounted and which is equipped with an abrasivesurface arranged to .cooperatewith the lap and which is capable of the required adjustments to restore the active surface of the lap to the original curve or curves, the

range of adjustment being such that a worn lap of any original spherical or toric surface may be restored for further use in lens grinding and polishing.

With the above and other objects in view, the 30 invention has particular relation to certain novel features of construction, operation and arrangement of parts, an example of which is given in this specification and illustrated in the accompanying drawings, wherein:

Figure 1 shows a side elevation of the lap retruing machine partly in section.

Figure 2 shows a cross sectional view of the stand taken on the line 22 of Figure l.

Figure 3 shows a side view partly in section, 4 taken at right angles to the view shown in Figure 1.

Figure 4 shows a'plan view. I

Figure 5 shows a cross sectional View taken on the line 55 of Figure 3.

Figure 6 shows a fragmentary side view partly in section, showing a modified form of the machine, and 1 I Figure 7 shows a fragmentary sectional view taken at right angles to the form shown in Fig- 50 ure 6. I a

Referring now more particularly to the drawings, wherein like numerals of reference designate same parts in each of the figures, the numeral -l designates a suitable stand which is tubular in form and mounted on the base 2. Fitted within the upper end of the stand there is a chuck 3 which is splined therein against rotation by the key 4. The upper end of this chuck extends above the stand and is upwardly tapered and blank as at 5 to fit into the socket 6 of the lap 6a to be ground. The tapering portion of the chuck has a lateral key I which is received in the keyway 8 of the shank of the lap whereby the lap is held against turning on the chuck. An intermediate portion 9 of the chuck is externally threaded and an adjusting nut I0 is threaded thereon andabuts the upper end of the stand whereby the chuck and the lap thereon may be vertically adjusted.

Vertically slidable on the support I there is a clamp I l which is splined thereon by the spline I2. The free ends of the clamp l'l have the outwardly turned corresponding lugs l 3, l3. A clamp screw I4 is fitted through one of said lugs and has a threaded connection with the other and the outer end of this screw has the grips l5, whereby the screw may be. turned to contract or expand the clamp ll. Laterally offset from, but rigidly secured to, said clamp there is the upstanding arm l6 and mounted on the upper end .of this arm to pivot on a horizontal axis is the yoke IT. This yoke is mounted to pivot on the spindle l8 which is secured to the arm I6. One end of the yoke is formed into the counterweight l9 and secured to the other end of the yoke thereis a vertical guide 29. slidable on said guide and having a dovetailed connection therewith there is a wrist bearing 2| in right angular relation to the axis of the spindle [8.

A screw shaft 22 is mounted to swivel in a vertical bearing 23 at the upper end of the guide and this shaft 22 has a threaded connection with the wrist bearing 2! whereby said bearing 2| may be adjusted vertically. The guide 20 carries a gauge 24 and the wrist bearing 2! is equipped with a pointer 25 whereby the point of adjustment of the bearing 2| may be approximately ascertained. For finer, or more accurate, adjustments the upper end. of the bearing 23 is provided with a gauge 26 and the adjacent portion of the shaft 22 is provided with a mark 2'! to indicate the adjustment of the shaft. The shaft 23 is equipped with a handle 28 whereby it may be turned.

There is a crank arm 29 one end of which is formed into a wrist 30 which works in the bearing 2|. The other end of this arm is arranged opposite the arm l6 and has a sleeve 3! provided to receive the lower end of the upstanding standard 32. The standard is secured in said sleeve by means of suitable set screws 33. There is a file holder 34, one end of which is formed with a vertical bearing 35, preferably square in cross sectional contour, and which is vertically slidable on the standard 32. The file holder may be secured at any point of adjustment on the standard by means of the set screw 36 which has a threaded connection with the wall of the bearing 35 and whose inner end is adapted to bear against said standard. The outer end of the set screw 36 is equipped with a g ip 3! whereby said set screw may be turned. The other end of the holder 34 is downwardly turned and provided with a lengthwise groove forming a seat 38 wherein the file 39 may be seated and secured by set screws 4|] threaded through the wall of said seat.

On the standard 32 thereis" argauger4l for indicating the radius of the dioptriccurvature of the operative surface of the lap 6a and the bearing 35aha'sya :side window 42 which carries the transverse indicating line 43.

When'the surface of the lapbecomes misshapen as aresult of use'it maybe removed from the lens. grinding'machine and mounted on the chuck 3 as-shown in Figures 1 and 3. Before mounting the lap in place; however, the screw. I4 is loosened and the clamp: I I elevated so as to move the holder 34 andifile'sSQ elevated out of theway, and the screw I4 maybe then tightened to cause the clamp I lgto. grip the stand I so as to'hold the parts in elevated position. The lap 8a may then be-mounted in. place. 'The screw35 may then be released and the file holder 34 adjusted with respect to the gauge 4Ito give the desired radius of :dioptric curvature, that is, the base curve and the screw 36 then tightened up to securely fasten the file holder to the standard-32.

The wrist bearing H is now adjusted inaccordance-With the particular contour desired for the toric surface of the lap. If said-last mentioned bearing be adjusted into a common horizontal plane with the bearing of theyoke IT and the file 39 be operated over the surface of the lap and about said bearings, as axes, a segment of a spherical surface will be produced on the lap. If the wrist bearing 2! be adjusted'out of the horizontal plane of the-yoke bearing the surface producedby the file39-on the lap will be varied from atruespherical segment and will approach a cylindrical surface, the variation in the particular form of the toric-suriace produced depending upon the relative adjustment of the two axes.

The screw I4 is then loosened and the clamp l I lowered until the file rests on the surface of the lap to be operated upon. The set screw I4 is then tightened up to cause the clamp to grip the stand.

As'will be noted by-an inspection of Figures 1 and 3, a wide range of adjustments has been provided for, to the end that any desired curvature of the operative face of the lap 6a may be produced. During the progress of the work the nut III may be adjusted from time to time, to hold the lap closely to the work. When the lap has been ground to the desired contour'it may be removed from the chuck ready for use in" the lens grinder or polisher.

As shown the'operative face of the-lap 6a is convex. This will produce a concave face on the lensground thereon. If it be desired to produce a convex face onthe lens, it is of course necessary'thatthe operative face of the lap be concave as shown in Figure 6. v

As shown in Figures-6 and '7 the-holder 34a is I provided with a socket 44 to receive the shank of the adjusting nut lUa. This nut is retained in the holder by means of the transverse pins 45 which are fitted through the annular groove 46 around said shank. The chuck 3a is threaded through the nut Illa. and the lower end of this chuck is tapered as at a to fit in the socket of the lap 61). The tapering portion of the chuck Bot has a lateral key I which is received by the keyway 8 of the shank of the lap 6b whereby said lap=is--held against turningon the chuck. The

lap. Bbhas a concave operative face 41.

In this form there is a fork 48 having a spindle :48a which is keyed in the upper end of the stand I, as shown in Figure 6, and mounted in the fork there is a-file, or other abrading member 39a. Thisfile39a is of a general cylindrical contour and it is provided with the end spindles 49 which are'mounted' to rotate in the bearings formed in the .arms of the fork 48. These spindles are held against rotation by the set screws 53, 5B. The surface of the abrading member 39a has the contour of a spherical segment and as the abrading surface becomes worn the member 39a may be .partiallyt-turnedifrom time to time by loosening the set screws 55!]. and upon making the adjustment again: tightening them up.

The weight [9 hereinabove referred to has been provided for'balancing the adjusting and grind- .ing'mechanism, hereinabove described, about the axis of the spindle I8.

" What I claim is:

13A: machine of the character described com- .prisingacstan'd a yoke mounted onthe stand to pivot ona horizontal axis, a standard, means for supporting the standard to pivot about a horizontal axis :onthe yoke, said supporting means being vertically adjustable, awork holder on the stand, a fileholder vertically. adjustable on the standard, .a file on the file holder adapted to contact: the work, means for fixing the fileholder at any. point of adjustment on the standard.

20A machinefof the character described comprising a stand, a vertically adjustable arm on ;the stand, means .for fixing the arm at any selected point of adjustment, a yoke mounted to :pivot ona'horizontal axis on the arm, a vertically adjustable bearing on the yoke,-means'for adjusting said bearing relative to said axis,v a standard support having a wrist mounted to pivot insaid bearing, an upstanding standard on saidsupport, a work holder on the standadapted toreceive and support the work to be operated on, a file holder,: means for fixing the file holder at any selected point of adjustment on the standard, :a "file on the holder in contact with the work.

'3.' Agrinding machine comprising astand, a yoke mountedon the stand to pivot on a horizontal axis, astandard, means for supporting the standard to pivot about a horizontal axis on the yoke, said supporting means being vertically adjustable, a work holder onthe stand, a file holder vertically-adjustable on the standard, a file on the file holder adapted to contactthe work, means for fixing the file holder at any point of adjustmento-n the standard-and means for adjusting the work on the stand.

4. A machine of the characterdescribed comprising a'stand', anarm adjustable longitudinally with respect to the stand, means for fixing the armat anyselected point of adjustment, a'yoke 'mounted-topivot on the arm on an axis at approximately right angles to the axis of the stand, a bearing on theyoke adjustable at approximately right angles to 'the axis on which the yoke pivots, means for adjusting said bearing relative to said last mentioned axis, a standard support having a wrist mounted to pivot in said bearing, an upstanding standard on the support, a work holder on the stand adapted to receive and support the workto be operated on, a file holder, means for fixing the file holder at any selected point of adjustment on the standard and a file on the holder in contact with the work.

5. A lap re-truing machine comprising a stand, an arm adjustable longitudinally with respect to the stand, means for securing the arm at a selected point of adjustment, a yoke mounted to pivot on the arm on an axis at approximately 15 right angles to the axis of the stand, a bearing on the yoke adjustable at approximately right angles to the axis on which the yoke pivots, means for adjusting said bearing relative to said last mentioned axis, a standard support having a wrist mounted to pivot in said bearing, an upstanding standard on said support, a work holder adapted to' receive and support the work to be operated on, a file holder and a file thereon, one of said holders being located on the stand and the other being located on the standard and' means for fixing one of said holders at a selected point of adjustment on its support with the file in contact with the work.

ROBERT S. DUKE.