US1454221A

US1454221A - Lens-grinding machine

Info

Publication number: US1454221A
Application number: US555383A
Authority: US
Inventors: Harry W Hill
Original assignee: American Optical Corp
Current assignee: American Optical Corp
Priority date: 1922-04-18
Filing date: 1922-04-18
Publication date: 1923-05-08
Anticipated expiration: 1940-05-08

Description

ay 8, 1923. 1,454,221 I H. w. HILL LENS GRINDING MACHINE Filed April 18, 1922 2 Sheets-Sheet 1 F/EI INVENTOR H. W H/LL AT ORNEYS May 8, 1923. 1,454,221

H. W. HILL LENS GRINDING MACHINE Filed April 18, 1922 2 Sheets-Sheet 2 INVENTOR H. W HIL L ATTORNEYS atented May 8, 1923.

NH E

REY W. HILL, OF SOUTHBRIDGE, MASSACHUSETTS, ASSIGNOR TO AMERICAN OPTICAL COMPANY, OF SOUTHBRIDGE, MASSACHUSETTS, A VOLUNTARY ASSO- CIATION' OF MASSACHUSETTS.

LENS-GRINDING MACHINE.

Application filed April 18, 1922. Serial No. 555,383.

To all whom it may concern:

Be it known that I, I'IARRY \V. HILL, a citizen of the United States, residing at Southbridge, in the county of Worcester and State of Massachusetts, have invented certain new and useful Improvements in Lens- Grinding Machines, of which the following is a specification.

This invention relates to new and useful improvements in grinding machines and more particularly to the provision of a new and novel machine for the grinding of toric lenses. The main object of the invention is the provision of a machine of simplified construction including a single driving member which if desired will produce the necessary variable motion for grinding and polishing toric lenses, particular emphasis being placed on the grinding of tone lenses as this is the most difficult lens to grind and polish satisfactorily.

Another object of the invention is the provision of a machine having a single can) serving to impart a progressively, variable reciprocating movement to produce a most satisfactory grinding motion to break up the general pathway so as to grlnd and polish the entire surface of the lens evenly.

With the above and other objects in view the invention consists in the novel features of construction, the combination and arrangement of parts herein-after more fully set forth, pointed out in the claims and shown in the accompanying drawings, 1n

which-- Figure I is a side elevation of a gr 1nd1ng machine constructed in accordance with my invention.

Figure II is a plan view.

Figure III is an enlarged plan illustrating the cam movement, and

Figure IV is a side elevation illustrating a slightly modified form of the machine.

In carrying out my invention I prefer to mount the same upon the supporting bench 1 having upright bearing standards 2 provided with bearings 3 at the upper end thereof. Mounted for rotation within the bearings 3 is the'main operating shaft 4 which extends beyond one of the bearings and has mounted thereon the lens blocks 5, said blocks being in the present instance as of circular form with a convex outer surface so that the concave side of the lens 6 may be readily mounted upon the blocks and secured thereon in the usual manner.

Extending upwardly from one of the bearings 3 are the spaced ears 7 and pivotally connected to these ears are the arms 8 of the bracket 9, said arms being mounted upon the p vot pins 10 to rovide for a loose swlngmg movement of t e bracket 9.

The horizontal arm 11 of the bracket 9 is provided at its outer end with a sleeve 12 and loosely mounted for movement in this sleeve is a rod 13 pivotally connected at its lower end to a closed arm 14, while mounted upon the upper end of the rod is a weight 15 which tends to normally press downwardly upon the rod 13 for the purpose of retainmg the laps 16 into enga ement with the surface of the lens 6. he laps 16 are loosely connected with the ends of the cross arms 14 as at 17 to provide for free swingmg movement of the laps 16 with respect to the movement of the arms 14.

In grlnding toric lenses it is necessary that a full even movement be imparted to the grmdmg lap so as to cover the entire surface of the lens 6 during the grinding and pollshmg operation and in order'to produce the proper movement for imparting a grindmg or polishing movement over the entire surface of the lens a barrel cam 18 is mounte'd upon the shaft 1 between the bearings 3, said cam being provided in its face with undulating progressively advancing groove 19, particular attention being directed to the fact that the groove 19 while being undulated progressively advancing from one side edge of the cam 18 to the other which imparts a variable reciprocating movement to the shaft 4 by having the stationary lug 20 vmoving within said groove. The lug 20 is secured to a bearing member 21 which in turn is rigidly connected to the base member or table 1.

In order to impart movement to the shaft 4 a pulley 22 is mounted upon the shaft and connected by means of a belt 23 to any suitable source of power whereby upon rotation of the pulley 22 the cam 18 will be rotated and thru its connection with the lug 20, which rides within the groove 19, a progressively variable reciprocating movement is im arted to the shaft 4 and as this shaft carries the lens blocks 5 the same movement will be imparted to the blocks whereby the grinding or polishing contact of the laps 16 will tend to cover the entire surface of the lens 6 so as to break up the grinding movement whereby the polishing of the lens surface will be equal thruout. In view of the fact that both the arms 14 and the laps 16 are mounted for pivotal or swinging movement the concave surfaces of the laps will comate with the convex face of the lens and provide for the proper grinding and polishing of the surface of the lens.

In Figure IV I have illustrated a slightly modified form of the invention wherein an additional pulley 24 is arranged between one of the bearing members 3 and the cam 18 and it will be noted from thisfigure that the pulley 22 is connected by means of the belt 23 to the main driving shaft 25 which has suitable pulleys 26 over which the belt 23 operates and the pulley 24 is connected by means of a belt 27 to one of the pulleys 26 whereby the

pulleys

22 and 24 will receive their power thru the rotation of the shaft 25.

The main driving shaft 25 is provided with a pulley 28 which may be'connected to any suitable source of power to impart movement to the shaft 25.

In the form illustrated in Figure IV the cam 18 and the pulley 24 are loosely mounted upon the shaft 4 while the pulley 22 is connected to the shaft to rotate the same.

' Connected to the shaft and arranged upon the outer face of the pulley 24 and the opposing face of the cam 18 are the collars 29 which limit the lateral movement of the pulley 24 and the cam 18 whereby as the lug 20' moves thru the groove 19 a progressively variable reciprocating movement will be imparted the shaft 4 while continued rotation of the shaft 4 is carried out thru the movement of the pulley 22.

Attention is now directed to the fact that the collar 30 upon which the cam 18 and the pulley 24 are mounted is rotating at a higher rate of speed than the shaft 4, in view of the fact that the pulley 24 is somewhat smaller than the pulley 22, while both of the pulleys receive their source of driving power ffom the same size pulley,

From the above it will be noted that by having the shaft 4.rotating at a slower rate of speed than the variable progressive cam 18 a further pathway will be defined upon the convex faces of the lens so as to break up the grinding or polishing movement upon each revolution of the blocks 5, thus assuring the fact that movement of the laps 6 will cover the entire surface of the lens and travel in a difierent pathway upon each revolution of the wheel 5 thus covering the entire surface of the lens in a variable pathfin the modified form of the invention shown in Figure IV the variable groove 19 1s the same as the preferred form of the inhigher rate of speed than the shaft 4' to positively produce a progressively variable movement of the grinding on polishing laps 'while passing over the surfaces of the lens.

In both forms of the invention it is preferred to have a receptacle 31 arranged beneath the lens blocks 5 so as to permit the lens to be moved thru the grinding or polishing material during the revolution so as to supply the faces of the lens with the proper amount of grinding or polishing material. A guide member 32 is mounted upon the

shafts

4 and 4 whereby to protect the bearings 3 from the grinding or polishing material which might be thrown from the blocks 5 during the revolution of the same.

From the above description taken in connection with the accompanying drawings it will be apparent that I have provided an improved machine for the grinding of toric lenses and wherein a single cam serves to impart a progressively varying reciprocating movement to produce the satisfactory grinding operation for breaking up the path of the grinding or polishing lap and producing a more satisfactorily finished lens.

What I claim is- 1. A machine of the class described in cluding rotatable lens blocks, lap members supported above the blocks and having contact with the lenses on said blocks and means the lens block whereby to whereby to impart a variable reciprocating movement to the lens blocks as and for the purpose set forth.

2. A machine of the class described including a driven shaft, lens blocks mounted upon one end of the shaft for rotation therewith, 1

and stationary means disposed within said groove whereby rotation of the cam will impart a progressively varying movement to the shaft as and for the purpose set forth.

3. A machine of the class described including a rotatable shaft, lens blocks supported upon one end thereof, lap members arranged above the blocks and contacting with the lens thereon. means for loosely supporting said lap members, a cam mounted upon the shaft having a progressively advancing groove in the face thereof, a stationary lug disposed within said groove and means for imparting rotary movement to the shaft and cam whereby the movement of the lug thru the groove will impart a progressively varying reciprocating movement to the shaft.

4. A machine of the class described including a rotatable shaft, lens blocks mount= ed upon said shaft and means whereby to the blocks and contacting with the lens impart a progressively varying reciprocatthereon and means whereby to impart a ing movement to said shaft as and for the progressively variably reciprocating movepurpose set forth. ment to the shaft as and for the purpose 5. A machine of the class described inset forth. eluding a rotatable shaft, lens blocks carried thereby, laps loosely mounted above HARRY W. HILL.