US 1001410 A
Description (OCR text may contain errors)
W. H. JOHNSON. MACHINE FOR GRINDING LENSES.
- APPLICATION FILED JAN.Z8.1911. 1,001,410.
Patented Aug. 22, 1911 IIIIIIIXIII w I H. JOHNSON; MACHINE FOR GRINDING LENSES. APPLIUATIORI'ILED JAN. 28, 1911.
Patented Aug. 22; 1911.
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WALTER H. JOHNSON, F EST 1 KBUlt'Z. MASSACHUEEUITS, ASSIGNOP. OF ONE-HALL TO CHARLES T. SAUL, O11 W'ALTl-IAM, MASSACHUSETTS.
MACHINE FOR GRINDING LENSES.
To all whom it may concern:
Be known that 1 WAi'xrnn ll. donation, a citizen of the United Staten. residing a test Rortbury, in the county o t Hutlolk and State of hilassaehusetts. have invented new and useful improvements in l\l-.iehines t'or GrindingLenses, of which the .t'ollowing a specification. This invention relates to machines grinding lenses.
The olfect of the invention to provide for a machine which will grind any kind of cylinder lens, toric or plain. and which will grind the convex or concave t'ares oi? lcnscs with very slight change in the parts.
The object of the machine is further to provide a machine which can be operated quickly and easily by comparatively inc:- perieneed and cheap operators.
in ju'iachines oil the character set l'orth it is very desirable that the grinding element should pass over the surface of the lens to he ground in a variety of paths, none ot which are duplicates of each other. To accomplish this result, the machine o'l' this invention is so constructed and operated that. the grinding element which moves over the surface (it the lens, or the lens itself when it is .n'iovtajl over the surface oi the work holder. has an iinleterminatc movement. inn parted lll8l1tt)-llltlii is. said tlotttt'tlt n iovc d and in another direction at an angle to the in one direction. by one mechanism Specification of Letters Patent.
.lirst by another mechanism, and these two:
n'wchanisms vary in their action relatively to each other, For the reason that one o1" them is driven by a slipping Frictional means, so that the two mechanisms are constantly changing in their relative times of movement and consequently the grinding element which is driven by these mechanisms moves in a resultant path which constantly varies and which cannot be predetermined, or, in-other words, is indeterminate, because of the fact that one of these mechanisms is driven by a slipping frictional means, and said means will slip according to the amount of resistance encountered at certain times by the moving grindingelement.
The invention consists in the combination and arrangement of parts set forth in the following. specification and particularly pointed out in the claims thereof.
Referring to' the drawings: Figure 1' is a plan View of my improved lens grinding Patented Aug. 22, 19M.
Application filed January 28, 1911. Serial No. (305,157.
machine. Fig. ".3 a side elevation viewed in the dirw-tion ol' the arrow n. Fig. l. and shown partly in section. l ig. it is a front elevation viewed from the right of l igis. l and illustrating the grimling members and work holder arranged to grind the concave side ot a lens. l ig. -l is a plan View of the grinding members and work holder, with the guide For preventing the gi'iiuling member t'roni rotating about its medium axial line in section. .l"ig. 5 is 'l'ront elevation viewed in the same direction as Fig. 11. illustrating the naichine with the grind ing nu-inbrr adapted to grind the convex side oi a lens. the same being shown partly in section. Fig. (3 is a front, elevation of a moditicd Form of means For preventing the movable grinding member from rotating about its median axial line. Fig. 7 is-a side elevation of the parts illustrated in Fig. (3 as viewed from the left of said Fig. (l.
Like numerals refer to like parts through out thr'scvcral views of the drawings.
in the drawings, id is the frame of the machine and It the main driving shaft journal d to rotate in a suitable bearing driving pulley i3 is fastened to the shaft- 2 and ionrnaled upon said shaft is a loose pulley t 1. another pulley '15 is fastened to th sha it it and has projecting from its lace and hot thereto a cranlepin 16. The crankpin il is connected by a crank-rod 17 to a slide it; by means of a pivotal connecting bolt ll), said crank rod 17 is movable laterally thereof on the crank pin it). The slide ,ltw' is guided in ways 20 Formed in a slide it which consists of a block 29 tastened to rods 23, 23. the rods 23% being adapted to slide in hearings 94., 94- formed on the standard which is a part of the frame of the machine.
A, reciprta'atory motion is imparted to the slide 21 by a. cam 26 loosely mounted to 1o tate upon the shaft. 11, and driven by a belt 27. This helt 537 is an endless belt and extends lrom the pulley 15 around idler guide pulleys 28, 30 and 31 and around the pulley 39 which is fast to the sum 26. To regulate the tension on the belt 27 the idler guide pulleys, via, the pulleys 3i and 29 are mounted upon a bracket which is adjustahly fastened by means of a bolt. 34 to the base 35 ol' the frame 10. The reciprocat'ory motion is imparted to the slide 21 from the cam 96 by acam lever 36 which is pivoted the other end thereof heingconnected by a pivotal stud 'l'O tothe block 22 which forms a portion of the slide 21, the whole of said slide consisting of the block 22, the cap )late fast thereto and the uide rods- The slide 18 has fastened to its front end a head 41. by means of a set-screw l2 and this head has slidably mounted therein a rod which has a. collar 4st fast thereto, said collar having a handle 44: fast thereto by means of which. it may be raised. interposed between said collar and the head 41 is a spring which encircles the rod 43 and tends t-o'hold said rod dowmvardly. The lower end of the rod 4-3 is rounded at 4:6 and fits into a recess 47 in the grinding clement 4-8 (Fi 2).
By reference to Figs. 2 and it will be seen that there are two elements 48 and 51 having opposed faces 53 and 52, respec tively one of said elements 48 constituting a grinding element and the other element 51 a work holder. The element 51 is convex upon its grinding surface 52 and has a lug 54c projecting downwardly therefrom into a recess 55 in the frame 10. Vt hen it is desired to grind the concave side of the lens 49, said. lens is interposed between the elements l8 and 51 and is fastened to the element 418 by means of a suitable cement,
In order 'to prevent the element 4:8 from irotatine' about the median axial line of the rod 43, or about a median axial'line extending substantially at right angles to the grinding surface of the element 51, a rod 56 is fastened to the grinding element 48 and projects therefrom toward th right (Fig. 3) into a slot 57 formed between the two K sides 58, 58 of a bracket 59 which is bent at right angles at'its upper'end and is preferably formed of. wire, the bracket 59 being fastened to the head 41 by a set screw 60. The rod 56 is extended to the left of the grinding element 48, as illustrated in Fig. 3, in order to enable the operator to conveniently and quickly lift the grinding element 48 away from the element 51 when it is desired to remove the lens from between the opposing faces of the ele ments 48 and 51 or to insert a new lens therebetween. This extension of the rod 56 to the left, Fig. 3, is also for the purpose of enabling the operator to remove the grinding element 48, with the lens attached thereto, and turn said grinding element around 180", thus reversing the positions of the right and left hand ends of the rod 56 and that portion which previously extended to the left of the grinding element 48 will then extend to the right of said grinding element-and into the slot 57 in the bracket 59.
in F 2 and the lens is illustrated as fastened to the uppergrinding element 48 and the convex grinding face 52 of the element 51 remains stationary, While the lens moved around by the mechanism hereinbefore described in the manner hereinafter more fully set forth. In Fig. 5, however, the grinding clement 1-8 is replaced by a grinding element 48' having a concave grind- A face 53' and the lens 49 is fastened by cement 50 to the element 51', which is ren'iorably fastened to the frame of the machine by means of a lug 54 which projects into the recess The rod 43 is'the same as in the form of my invention illustrated in Figs; 1 and 2; also the guiding bracket 59, and the element 48 are provided with rods 56 and 56 which perform the same functions as the rod 56 in the form of my invention illustrated in Fig. 3.
in Fi and '7 I have illustrated a modified means for preventing the lens from rotating around an axis substantially at right angles to its surface during the grindin operation, and referring to said Figs. 6 an 7 it will be seen that the element 5]. is supported on the frame of the machine as in the forms of my invent-ionv illustrated in l i s. 2 and 5, While the grinding element -1-8, which, in this particular form has the lens l9 fast thereto, is pivota'lly mounted .to rock upon the rounded end of the rod 43, as hereinbefore described, the element 48 having cars 61, 61 thereon which straddle ti -shaped rods 56, 56* which are fastened to a collar 62 which, in turn, is fastened to the rod The general operation of the machine hereinbefore specifically described is as 'follows. Considering, first, the-grinding of a lens on the concave face thereof and referring to Figs. 1, and 3, the operator attaches the lens 49 to the grinding element 48 by means of suitable cement as illustrated in Figs 2 and 3, and utilizes for the other element the part 51'. He places the part 5-1 in the position illustrated in Figs. 2 and 3 and covers the same with a suitable grinding material, then. raises the rod 43, by means of the handle 4-4, overcoming the action of the spring He then places the lens 49 attached to the grinding member 48 by the cement 50, beneath the rod 43 and lowers said rod until the rounded lower end 46 thereof enters the recess 4:? in the grinding He lowers the rod 43 and the element element 48 with the lens attached thereto, manipulating the rod to this end by means of the handle 44 and the grinding element 48 and lens by means of the handle or rod He then starts the machine by slipping the belt from the loose pulley 14 onto the tight pulley 13( The shaft 11 is then rotatedand this imparts a reciprocatory motion to the slide 18 from the front; to the back' of the machine, while the cam 32b will be rotated loosely upon the shaft; 16 by the belt. 27, and this will rock the cam lever 36 and.
through the link 38, the slide it. will he given a reciprocatvory motion at. an angle (in this case at, right angles) to the. direction of motion of the slide 18. The resultant motion imparted to the grinding clement to, due to the combined movements of the two slides 18 and it will move said grinding element in dilletrnt. directions around over the element 51., thus grinding the concave surface of the lens 'll) which is in contact with the grinding material upon the convex surface 52 of said elen'ient It is evident that the grinding element t9 and the lens attached thereto can tip in ditferent directions as it is moved around in a curvilinear path by the mechanism hereinbefore described. The distance, lic-iwever, to which said lens can be rocked about the median axial line of the rod 43 is limited by the rod 56 which projects into the slot 57 between the two sides 58, 58 ot the bracket 59. This rod can tip upwardly and down wardly, but limits the angle to which the element 48 can be rotated, together with the lens, about said median axial line.
It will be understood that the belt 27 is loose enough so that it a certain amount of resistance to the movement of the grinding element 48 and the lens attached thereto is encountered said belt will slip upon the pul leys and, therefore, the relative location of the cam 26 to the belt- 15 and to the crank pin 16 fast thereto will be changed and as soon as this occurs the path which the element stSwould otherwise have descrilaid will be changed. This change occurs according to the amount of resistance and the number of dill'erent times that a certain excess ot resistance, so to speak. occurs-during the grinding operation and, thcrc'tore, the resultant path imparted to the grinding element 48 and the lens attached thereto is indeterminate, and also it will be umlerstood that because of this slipping connection between the pulleys '15 and 32, the movcnwnt il'nparted to the grinding element is indeterminate movement, and, further that one of said elements, vim, in this embodiment ol my invention, the element 1-8, will be moved in a plurality of directions at an angle to each other relatively to the element 51.
It will be noted that the handle -l-l; has screw-threaded engagement with the collar 4i and, tln-u'e'fore. acts as a set-screw to l'asten the collar 44 to the rod 43. It it is, desired. therefore, to increase or diminish the tension upon the spring 45. it can be done by loosening the set'screw handle ll and moving the collar 4 t upwardly or downwardly, respectively, according as it is desired to inijzrease or diminish the tension upon the spring This. of course. results in increasing or diminishing the pressure of the lens against the grinding snrl'ace.
When it is desired to grind a convex surface on a lens, the parts illustrated in Fig. I)
are utilized. in this case the under side of the element to is made concave and the lens ll is fastened to the element a which may tune a convex upper sin-lace or not. as desired. The mechanism is the same as that i|lu.--;tratcd in Figs. l. .2 and 33 and in the operation of the machine in this embodiment of my invention the lens remains stationary. while the element 41'1" slides around upon its convex surl'acc. there being introduced between the grinding element 18' and the upper convex surface ol the lens, suitable grinding material.
in Figs. 13 and T the grinding element i8 is provided with cars which engage the U- shaped rods 56 and all, and thus said rods 56 and 5(3 allow the grinding element in to rock, together with the lens. as it is moved around upon the convex surface of the part 51". but do not allow said grinding clement l8 to rotate about the axis of the rod 423. In this embodiment of my invention. the othcr parts of the machine are the same as illus trated in Figs. l, '2 and 2Shereinbel'ore described.
, Having thus described myinvention, what l claim and desire by Letters Patent to secure, is:
l. A machine for grinding lenses having, in combination, two elements having opposcd surlaces one of said elements constituting a work holder and the otlu a grimling element. two slides. one mounted on the other, said slides adapted to s' dc re. 'ieclivcly at an angle to each other. one of said elements pivotally connected to one of said slides. a crank-pin, a crank rod com'iecting said crank-pin to one ol said slides and movable latcrally thereof on said crank-pin. a. cam. and mechanism operativcly connecting said cam to the other of said slides, and means 'l'orming a slipping frictional conncction between said crank-pin and cam.
J. machine for grinding lenses having, in combination. two elements havingopposed snrl'aces one of said elements constituting a work holder and the other a grinding element. two :lidcs. one mounted on the other. said slides adapted to slide respectively at an angle to each other. one of said elements pivotally connected to one ol said slides. a. pulley, a crank-pin fast thereto. a crank-rod connecting said crank-pin to one of said slides and mo\ able laterally thereof on said crank pin, a cam and mechanism operalively onnecting said cam to thi other ot said slides. a. pulley fast to said cam, and an eudless belt connecting said pulleys and adapted to slip thereon.
3. A machine for grinding lenseshaving, in combination, two elements having opposed surfaces one'of said elements constituting a Work holder and the other a grind ing element, two slides, one mounted on the other, said slides adapted to slide respectively at an angle to each other, one of said elements pivotally connected to one of said slides, a pulley, a crank-pin fast thereto, a crank-rod eonnecting'said crank-pin to one of said slides and movable laterally thereof on said crank-pin, a cam, mechanism operati'vely connecting said cam to the other of said slides, a pulley fast to said cam, an endless beltconnecting said-pulleys and adapted to slip thereo11,.and means to adjust the tension on said belt.
4. Armachine for grinding lenses having, in combination, two elements having opposed surfaces one of said elements constituting a work holder and the other a grinding element, two slides, one mounted on theother, said slides'adapted to slide respectively at an angle to each other, one ofsaid elements pivotally connected to one of said slides, a pulley, a crank-pin fast thereto, a
to guide said belt, one of said idler pulleysv being adjustable, whereby the tension on said belt may be varied and said belt allowed to slip.
In testimony whereof I have hereunto set my hand in presence of two subscribing Witnesses.
WALTER H. JOHNSON.
CHARLES S. GOODING, Louis A. Jones.