US1593212A - Lens-surfacing machine - Google Patents

Description

July 20 1926.A

E. HART LENS sURFAcING MACHINE Filed Oct. 2, I1920 4 Sheets-Sh'et l July 2o 1926. f 1,593,212

E. HART LENS SURFAC ING MACHINE Filed OCC- 2, 1920 4 Sheets-Sheet 2 July 20 1926.

E. HART LENS SURFACING MACHINE Filed OGL* 2, 1920 4 Sheets-Sheet 5 E. HART LENS sURFAcING MACHINE July 20 1926. 1,593,212

Filed Oct.. 2, 1920 4 Sheets-Sheet 4 BW gx Awww/EY Patented July 20, 1926.

UNITED STATES PATENT OFFICE.

EDWIN HART, OF ROCHESTER, NEW YORK. ASSIGN OR TO BAUSCH & LOMB OPTICAL COMPANY, or ROCHESTER, NEW

YORK, A CORPORATION OF NEW YORK.

LEN S-SURFACING MACHINE.

Application filed October 2, 1920. Serial No. 414,230.

My present invention rela-tes to grinding machinery and more particularly to machines for forming lenses and it has for its object to provide a simple, durable and efficlent machine of compact; proportions for surfacing lenses the improvements being directed in part toward providing means for diversifying to a high degree the path of thel lens block or the relative movement of the lens and the abrading or polishing surface with which it is in contact. ject of the invention is to provide an attachment for controlling the movements of the l lens block during Work on toric lensesand to these and other ends the invention resides in certain improvements and combinations of parts all as will be hereinafter more fully described the novel features being pointed out in-the claims at the end of the specification.

In the drawings:

Figure 1 is a side View oi a lens surfacing machine constructed' in accordance with and illustrating one embodiment of my invention;

Figure 2 is a front view thereof;

Figure 3 is a rear View;

Figure 4 is a top view;

Figure 5 is a fragmentary section yon the lines 5-5 and 5".,-5x of Figure 4;

Figure is a vertical central section taken in a plane extending from front to rear of the machine;

Figure 7 is a central vertical section with parts broken away, taken in a plane extendlng transversely of the machine;

Figure 8 is an enlarged horizontal section through the frame showinglin plan view the Figure 9 is an enlarged section :on the line 9 9 of' Figure 6;

Fi line tion; V y p V- Figure 11 is 'a'section on the'line 11+-11 ofF1gure6,and

Figure .12 is a section on the line`12+12 of. Figure 6. v

f" Similar reference numerals throughout the several views indicate the same parts.

The machine of the present embodiment of the invention is designed for use as' a surfacing and polishing machine and comprises a frame 1 having a hollow base or bed utl showing the parts in another posi- 2 and, above the latter, a head 3 in the form .,i

A further ob-lurc to which the rouge or ure 10 is a similar section on the same th of a gear case. v Referring first to the lower mechanism associated with the bed 2, there is mounted Within the latter in cone bearings 4 formed by set screws 5 a rock shaft 6 provided centrally with an enlargement 7 in which is.' mounted a tapered post 8. These parts extend upwardly through `an opening 9 in the base and the post 8 cariiies the cast iron or other detachable grinding shell 10 havingl the grinding face `11 of proper curvaabrasive is apaccording to well mown principles or the shell surface is covered with felt or flannel for polishing puroses. Beneath the shell on the enlargement i an annular tray 12 conceals the openin 9 plied to surface the lens and catches the drippings from the shell,

thus protecting the moving parts below. A rigid arm 13 shown in full lines in Figure 7 and in dotted lines in Figure 1, extends. rear- Wardly from the rock shaft 6 and is provided with a wrist pin bearing 14 and pin 15 connecting the arm to a vertically disposed eccentric rod 16 whereby the rock shaft 6 is operated to slowly oscillate the shell 10 in a front to rear direction for purposes hereinafter explained; Y A strap 17 at the upper end of the rod 16 (Figure 5) embraces an eccentric 18 on the main driving shaft 19 of the machine which shaft extends transversely through the head 3. It is itted with a driving pulley 20 enclosing clutch, mechanism and reducing mechanism for the eccentric (the latter being indirectly mounted on the shaft through the medium of a sleeve 21, Figure 5) controlled by exterior knurledI operating elements 22 and 23 but these details need tion.

The vlens block. or holder and the one in piece or lens L is the lusual button 24 to which the lens is .cemented and it isdriven by mechanism suspended from the head 3. In the under side of the latter is a vertical bearing 25 alined with the post 8 of the lower mechanism ard turning in this bearing is' a sleeve 26. A worm gear 27 integral with the sleeve or vfixed thereon takes the thrust against the upper end 28 of the bearingrwhile a cap nut 29 engages correspondingly at the lower end (Figure 6). A worm 30 extending transversely through the head' 3 drives the sleeve relatively slowly not be further explained as they form no part of the present inven e present instance, which carries the workl through the medium of the gear 27 and the worm as shown in Figure 7 is driven from the main shaft 19 through gears 31 and 32.

Extending eccentrically through the sleeve 26 and having its bearing therein 1s a spindle 33 that is also capable of belng reciprocated longitudinally7 for which purpose its driving connections include a key way 34 formed therein .and shdably engaged by a key 35 regulated by a set screw 36 in a disc 37 surrounding the upper end of the spindle and resting upon the upper end of the sleeve 26. A packed cap plate 38 overlying the. disc beneath an opening 39 in the cover 40 of the head 3 through which the spindle extends protects these and other bearing surfaces from dust'and dirt. Rotatably mounted on the sleeve 26 below the d'isc 37 and held in place by a collar 41 is a spiral gear 42 meshing with a spiral gea-r 43 on the main driving shaft 19. An upwardly extending pinv 44 on the gear 42 takes into a radial slot 45 in the disc 37 containing the key 35 and the spindle is thus driven by the disc from the gearing L)i2-43, the slot and pin connection taking care of the revolvin movement of the spindle due to its eccentricity in the driven sleeve 26 that is otherwise rotated as before described. There is thus given to the spindle both a. rotating and a revolving motion.

At its lower end the spindle carries a radially extending slotted dog 46, the spindle being bifurcated for the purpose and the dog being secured in the desired position by a bolt 47. Above it is an annular tray 48 pinned to the spindle at 49 to catch impurities that might otherwise drop upon the grinding surface from the bearings in the head. An offset finger V5() on the dog 26 engages in a socket member 51 havingv a'ball and socketI connection shown at 52 with the button 24 on which the lens L is carried. The dog 46 is adjusted to take care of buttons and shells of different sizes used for grinding lenses of diiferent sizes. It will be seen from the foregoing that the spindle 33 rotates at a relatively high 'speed while undergoing a revolving movement due to thellower speed of rotation of the sleeve 26 in which it iseccentrically carried` so that the` path of the lens on the finishing or polishing shell 10 is much diversified, giving a uniform grinding or polishing action, but in addition to this and to prevent waves in the polished surface beyond any possibility, I provide the slow rocking motion from the eccentric rod 16 for the shell 10.

The grinding pressure and that for holding the dog 46 in the socket member of the button is provided by a lever 53 mounted on top of the head 3 and turning on a shaft 54 which itself. is capable of turning in bearings arranged in brackets 55 on the head cover 40. The lever is connected to the spindle 33 by links 56, the lower ends of which are pivoted to a cross head 57 slidable transversely on the spindle beneath a cap 58 (Figure 2) to compensate for the eccentric motion of the spindle. By this means the spindle may be lifted to disengage the dog 46 for inspecting the work or to change or interchange the grinding parts. Downward pressure is communicated to the spindle in the reverse direction by a finger 59 on the under side of the lever 53 that bears upon the cap'58 at the upper end of the spindle. The normal grinding pressure is maintained by a spr-ing best shown in Figures 4 and 6 having anintermediate loop 60 bearing upon the lever 53 and its end portions wound about the shaft 54 and secured thereto by pins 61. Thus, rotating the shaft 54 increases or decreases the tension of the spring and hence the pressure and thisrotation is effected by a worm gear 62 driven by a worm 63 on a hand operated shaft 64 having a hearing at 65 and provided with a knurled thumb-piece.

In the present instance, I have shown the socket member 51 carried by and threaded in the arm 67 of what I term a toric attachment by 'means of which the button is guided in the two planes of curvature of a toric lens. The said arm is bifurcated. as shown at 68, and carries a wrist pin 69 by means of which it is mounted in a bearing 70 adjustably mounted for height on a rod 71 by means of a set screw 72. The lower end of the rod 71 is bifurcated at 73 to carry a wrist pin 74 having a bearing in a member 75 permitting the rod to rock laterally of the machine. The bearing 75 is itself carried by a relatively transverse rock sha-ft 76 extending transversely of the machine and supported in cone bearings provided by set screws 77 in the sides of the hase 2, as clearly shown in Figure 3 and this provides for a movement in a. front to rear direction. In other words. the arm 67 has a universal movement and may rock forwardly and rearwardly on one curve and transversely on the other.

A machine constructed in accordance with my invention is simple and compact. convenient to operate and adjust and gives highly uniform results on the grinding surface.

f I claimas my invention:

. 1. In a lens surfacing machine` the combination with anon-rotatable grinding shell, of a lens block cooperating therewith. means for imparting a planetary movement thereto upon the surface of theshell and means ,for pivotally oscillating the shell relatively to the orbital path of the lens block.

2. In a lens surfacing machine, the combination with a grinding shell and a rotary lens block cooperating therewith, means for imparting a. planetary movement thereto on the surface of the shell, of means for rellilil peatedly oscillating-the shell about an axis in a direction transverse to the axis of the lens block.

3. In a lens surfacing machine, the combinationwith a grinding shell, of a rotary lens block cooperating therewith, means for rotating and revolving the lens block 'on the surface of the shell, and means for pivotally oscillating the shell.

4. In a lens surfacing machine, the combi'- tion With a frame, a grinding shell pivotally mounted thereon for oscillating movement, and means for oscillating the same, of a lens block cooperating with the shell, a sleeve having bearings inthe frame, means for rovtating the sleeve, a shaft eccentrically mounted in the sleeve and adapted to rotate the lens block an'd means for driving the shaft.

5. In a lens surfacing machine, the combination with a frame, ar'otary sleeve having bearings therein and a rotary shaft eccentrically mounted in the sleeve, of a rock shaft, means for driving the same, ing lens block driven by the rotary shaft and cooperating with the shell.

6. ln a lenssuracing machine, the combination with a frame, a grinding shell mounted thereon, a lens block cooperating with the shell and a reciprocator'y and rotar shaft in the frame for driving the lens block, of an arm*4 operatively connected to the shaft to reciprocate the same and to press the lens block against the shell, a rock Shaft for said arm, a spring secured to the rocklshaft and bearing against thel arm and means for ad- 'u'stably rotating the rock the tension of the spring.

EDWIN HART.

agrint,y shell carried on the rock shaft and a"` shaft to change

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