US1988649A - Grinding or polishing machine - Google Patents

Description

Jan. 22, 1935. v c. E. EVANS I 1,

GRINDING 0R POLISHING MACHINE Filed April 18, 1932 HA5 ATTORNEYS.

IN VEN TOR.

Patented Jan. 22, 1935 orurnnriq or;

. q tlharles lt.Evans;iAurora,111.;

iApplica t'ibn April s, 1932, ,jS erialNo;.605,907

.:"I'his1invention .relatesto a maehine for grind-: ing or polishingssurfaces, and has for itsmain object-to provide anv improve machine of this character'for performing these operations onvarious types of'lenses, particularly spectacle lenses, and also on mirrors, reflectors, etc. Another object of. my invention isto provide an improved, machine of. this :character especially-adapted for. grindingor polishing spectacle lenses whose sur-. faces are not truly spherical, such as lenses shown and described in my co-pending. application Serial No.'-579,451', after' the surfaces of such lenses have been shapedto the: desired form bywa; previous grinding operati'oni A further object of my. invention is to; provide animproved grinding. or polishing member which will readily "adapt itself to; the surfaces of lenses of curvatures. different from that of said mmbenitself, and which is j' capable of imparting substantially uniform pressure over the'lens surface whilethejla'tter is being operatedupon. The inventionconsists in certain features and elements of construction, in combination," asherein shown and described, and as indicated by the claims. Figures and 2--are side elevationgand-iplan views res'pect-ively' -"of i an" elementary ,form of grinding or p'olishing machine embodyingglmy in-. vention; '1 I "I -'-:Fig'ure-3.is.as' ionthrougha n'iodii'led form 'of:grinding"or polishing member 1 i J Figure 4showsra'further modificatio of grinding or polishing member. 1 For 'p'urposes of illustration; 1; have. chosen" to embody my invention in a very; elementary form, may; be seen inthe drawing. .fsupportedjon the bench, A-, or other, suitable standard, isja vertically disposed drive shaft, B, journaled at its .lowerend in a bearing, C, andat its upper end in a, thrust bearin t D. I .Rigidily secured jt'o the lower ndfo'f the. shaft, B, immediatelyaboye the ,bearing, 'C, is a drive. wheel or pulley, E, aroundjwhic'his' trained a flexible belt, F, which may he understood toi beconnected to a suitable fsourcefp'f; power, (not shown) 'Rigidly secured to jtheupp'enend of the shaft, 3-, is amp-shaped support," G, "which" is formed at its bottom with 'a hub portion, G supported'on the upper end of the e'nd thrust bearing'D. Secured-in this .cupshaped support many suitable :manner' is my improved grinding or polishing member, 'H,'.-which in Figure 1 of'the'drawing-is'shownjas-of hol- :low spherical form, and which' may-be understood to contain fluid, that is, either gas'or liquid;

the outerqsurfacei of thesphericahniember, H,

being-formed of flexible materialsuch as rubber so as to render the surface of said member flexible; and resilient; l r esir d this ndin polishing m er may be of modified form,-.as indicated at;H in

Figure 3. In this construction themember is formed of a mass of resilientmaterial-such as sponge rubber, which meets the requirement of, a suitable support for a flexible andrresilientsun;

face. J L

' Secured on the upperportion. of said spherical grinding or-polishing member, H, inany suitable manner, as by adhesives,-is a pieceof material, ;I,- suchas-felt or other suitable substances: ,Itis the outer surface of this piece of; fabric', I, which is the; effective,- grinding or; polishing surface, when supplied" with the necessary. grindingbr polishingscompounds; suchas rougerj 11f desiredthis fabric may be anchoredinplace on the ,mem-;-, ber, H, by lacing it' to the'support,

Mounted on the top of the bench, A, adjacent saidgrinding element. is. a bracket, J towhich is connected for universal movementaa' hand-"lever, L; The universal connection between thelhand lever and the. bracket consists of a horizontally extendingpin, K,'to. the inner end of'which'the lever, 'L, is. .pivotallyl attached by means 'of *a transverse, horizontal pivot pin, K As may be seen in the drawing the. lever,iL," mayfber; rotated. about the-horizontal axis of the"pin, K, which issubstantiallyin'alignment with the c'enter of curvature of the outer surfacei'of .the grind ing or polishing member, H; the purpose ofthis arrangement will hereinafter beimade apparent. Adjustably threaded through a boss of the lever, L, substantially radial relation 'to..thei memb er, H, is a spindle, M, the lower end of which projects into a socket formed in the top ,of the member, P, .which'is similar to what is commercially known as a .fblocking body'and' which is 5 in fact the carrier/forthe lens indicated-vat Q.

It isto be understood that the lens, Q, is adhesive.- ly secured to the carrier, P, by any suitable known method. 4

It may be understood. that the lens; shown in the drawing, has a concave surface in contact 'withJthe grinding or polishing surface of .,the-- member, In the normal operation. of a. ma"- chineof; this character the shaft, B, rotates counter-clockwise, and the hand lever, --=L,-i s

faceof the lens, that is being qnera edilpc center of the member, H, permits moving the lens overft l'ie' surf ce of the member;- I I, in a triie spherida-l' are. When the lever, L, is" positicned with the lens, Q, substantially centered on the member, H, said lens'will tend to spin about the end of its spindle, M, at approximately thesame rate of speed as the surface spaor thatpa'it of said member, H, which is engaged therebyr And when said lever is shifted sidew ise, the dif ference in frictional pressures on diiierii't areas of the lens will cause the lens to spin at a van-7'; able speed resulting in slippage between the surface of the lefis jandthe' surface armament: be'r; H, positively causinggrin ihg or ishing of the lenssurface. To in ur'e against possibility o'f th carrier and the lens being accidentally disengaged mm the" spindle is'filt: ing in danger of'injury to the operator,-

well as breakage of the'l si'the' socket for the end of the spindle, the carri r block, P, is

Because of the flexibility of the surface of the g-ilhdln'g' (if-polishing lehieiitfl-l, with which the'lens is p esse into c'oiitaet, and the relatibn of t e point ortiie spindle, to this serrate; there is a' ten ency or tr eiei waid edge or the ntp the surface of the grinding or polishing:melnber;particularlywhen lens is rocked to'the 'iight-side 6f the ve r't'ieaicentr, and mi overcomingthis-'diificulty the lever, 'nj is termed with) a pair of lugs; R; in which is joi'ir' naleda roller, sgwhich'niay be understood to be mounted on antif'frlction bearings.- This rcller is dimensioned and positioned. to come'i'n contact with the upper flanged surrane of the? ienseaw ri'er,-P, and is adapted toexertpres'sureia't the rear edge of said blbck,-so that the'fo'rward edge of the lens will be held fromutobsevere. engagement with the surface-cf the grinding or':po1ishing"element,tH.'- i Y I By virtue: of the construction embodied: in'my. novel grinding and polishing :lementpit will .be appareritthat such aimeinb'er is adapted to .be used for grinding or polishing the surfaces of lenses having" quite a wide range of curvatures, preferably curvatures WI'IOSB, radii are greater than the *normal; radius"or curvature of said memberyi Itwill also be seen that such atgrinding or V polishing member may be conveniently employed for 'grindi-ngxor polishing the 'sinface of alens having a truly sphericalcurvaturie. It is alsoimanifest' that my: improved polishing member, H, having a flexible and resilient surface readily adapts itself advantageously for use with certain-commercial methods wherein it is desirable to grind or polish a number of lenses atone time; such as-where several lenses are supported on a common iblocking'b'ody for en gage'ment Iwith a-=single grindingor polishing member which is of'prop'er shape and size, It

may beeliuaiiy adaptable to a method-wherein severall'ehses are" secured to the iiinr wall of'a "IifiBIi lbel" surfaces "of 'S'Etld lenses engaged by a commonlap block: In the latter method it is to'be understobd that e ci'i'p th i to proper'relati-v'e motions-for obtaining the as Figure l and is formed with a vertical marginal was, U

A flexible diaphragm, V, is stretched overthe upper edges of said vertical wall, U of the suppbrt and has its marginal edges rigidly "secured to the wall, U by an encompassing band,- W. ,The bottom wall of the cup-shaped stipptirt'; U; rarities with a nipple, Y, which fmaybeilinderstood to be provided with the usual check valve for admitting gas into the sealed dfiaifiberf'foiihedby the clip suppcrt U, and ithe diaphragm V: Bytlie use of such a valve it'wi-ll be"dbvioiis "thatjthepres'sure withinthe contain-'- er' may be varieddesired but preferably it is s'u'ili'eieritts cause the diaphragm St'o' bulge out war-my, producing a" convexly curved resilientsurface; as seen in" the drawing. It may be undrstood that the flexible :dia-phia'gm may .be formed-ti a material whose characteristics are such as" permit it'to serve as' the effective grind er polishing sur'face; or a-tpiece of felt or other suitable material may be secured thereto iii the usual way; grinding or polishing ele-- ment of this character provides asubstantially flat grinding or polishing surface, which ispartieularly' well adapted? foruse imgrinding or polishi rigthe convex surface of alens. Under'certaih-conditionsit may ,be desirable to have the diaphragm, 4V, stretched straight across the bowl; U, withthe" pressure in-the bowl at substantially atmospheric pressure, .or perhapsbyreduc-ing the pressure inwthe bowl the diaphragm may be drawn downwardlyv to present a concave working surface. 5 vt 4;

Although I hav shown and-described an eleineii'tary embodiment: of my invention; it is manifest-that it'i's' capable of modification'and' re ar'rang'ement without departing from the spirit and scope thereof. I do not therefore wish-tube iifider's'tood iniifiting- "myself to the particular construction herei'rishown and described, except asindicated by the "appended claims.

11- hi grinding or polishing machine ineluding a iotafysj ippoit, a grinding or polishing member carried by said support; said member having a curved resilient" wall portion, adapted for conforming t the surface cf lens of differnt' curvature, a hinged support,a lens bldcli associated with said support and arranged to ac con'irnodate itself to a substantial range of "versai movement, said hinged conne'ction'o'f the support permitting disposing a' lens inp'roper relation to said me mber, and permitting' oscillation of the lens back-and-forth over said resilient grinding or polishing surface ofthe member, and meanscarried on said support and engageable with one edge of the block for rocking the opposite e'dge' of the lens outwardly with respect to saidim'mber. n I I 2'. In a lens grinding orp'olishii'ig machine inclu'din'g a'rotary support, a grinding or polishing hemb'erearriedby said support, said memb r having st'uives resilient wall portionya'dapted for conforming to the surface of a lens of different curvature, a hinged support, and a lens block associated with said support and arranged to accommodate itself to a substantial range of universal movement, said hinged connection of the support permitting disposing a lens in proper relation to said member, and permitting oscillation of the lens back-and-forth over said resilient grinding or polishing surface of the member, the axis of the hinged connection of the support which permits said back-and-forth oscillation, being approximately in alignment with the center about which said curved surface of the grinding and polishing member is generated.

3. In a grinding or polishing machine of the character described, a hinged support, a lens block associated with said support and arranged to accommodate itself to a substantial range of universal movement for permitting the lens to accommodate itself in proper relation to the grinding or polishing member, and means for limiting the movement of the lens block in cer- 10 tain directions.

' CHARLES E. EVANS.

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