US2380446A - Machine for generating curved surfaces - Google Patents

Description

July 31, 1945. w. J. JOYCE ET AL I 2,330,445

MACHINE FOR GENERATING CURVED SURFACES Filed May 21, 1945 2 Shets-Sheet 1 l3 INVENTOR WILLIAM JOYCE dACKSON 4*; 4 BY GEORGE July 31, 1945. w J JOYCE AL 2,380,446.

MACHINE FOR GENERATING CURVED SURFACES Filed May 21, 1943 2 Sheets-Sheet 2 IN VEN TOR WILLIAM J. JOYCE BY GEORGE W JACg'SON ZTTORNEY Patented July 31, 1945 UNITED STATES. PATENT OFFICE I zssosss Company, 1 Hana, a voluntary association of Ma-achasetts Application May 21, ms. semi No. mm

5 Claims. (01. 00-24) This invention relates to curve generating devices and has particular reference to an auxiliary attachment adapted for use with standard curve generating devices commonly known in the art as lap truing machines. for producing tools for generating curved surfaces on lenses and method of making the same.

The principal object of the invention is to provide an auxiliary attachment for lap truing machines adapted particularly to increase the curve generating range of such machines whereby surfaces of relatively long radii of curvatures beyond the range obtainable by'the inherent lap truing machines maybe obtained.

Another object of the invention is to provide an auxiliary attachment for standard lap truing machines which may be quickly and easily supported in operative position without altering the general initial operating characteristics of the lap truing machine.

Another object is to provide an auxiliary attachment readily attachable to a standard lap truing machine whereby the powerv generating parts of said machine are utilized to obtain the operative function 01' said auxiliary attachment.

Other objects and advantages of the invention will become apparent from the following description taken in connection with the accompanying drawings and it will be apparent that many changes may be made in the details of construction, arrangement of parts and methods shown surface curvatures which they were capable of producing with the limitations being primarily in weak orshallow curve generations,suchcurves beingcommonlyknownasthosehavingarelatively long radius of curvature. The reason for suchlimitationwasthatmachinesofthisnature areusedbylensdlspenserswhmin most instances, do business in oflice buildings whicharelimltedinarearequiringsuchmachinestcberestrictedastosise. 'Withoutthis limitation it would be possible to produce substantially all of the curve generations required. Inthepast,whenshallowcurvedlapswererequired, such laps were inmost instances obtained from optical manufacturers who have the facilities for producing them. 'Zfliiswas withaviewto enablingthecommereiallaptmingmachinesto bepracticalforsmailsbopuse'Althoughthe prior rt lap machines did not produce the full range of curvaturesoflaps requiredthey did produce some of the most essential cums generations. This, however, has been a decided handicaptolens dispcnsersastimehas beenlostinthepastinhavingtosendtotho factory for shallow curve laps when such laps were required.

and described-without departing from the spirit of theinvention as expressed in the accompanying claims. We, therefore. do not wish to be limited to the exact details of construction, arrangement of parts and methods shown and described as the preferred forms only have been given by way of illustration.

Referring to the drawings:

Fig. 1 is a perspective view of a standard lap truing machine showing the auxiliary attachment of the'invention in operative position.

Fig. 2 is a plan view of the device illustrated in Fla. 1;

Fig. 3 is a fragmentary side elevation of said device; and V Fig. iisafragmentaryenlargedsectionalview takeglasonlineL-loflrig.8.

Machines to which the device embodying the invention are applied are commonly known i the art as lap truing machines which are capabli of generating diiferent surface curvatures on laps used in forming curved surfaces on lenses. laptruingmachinesofthisnatureinthepsst. havebsen limited astothenumber-of diifercnt The present invention, therefore, is adapted particularly to overcome this difliculty through the provision of an auxiliary attachment through which the required shallow curve generations could be obtained particularly without requiring redesigning of the commercial lap truing machines already in use.

Referring more particularly to the drawings wherein like characters of reference designate like parts throughout the several views, in the figures there is illustrated one of the commonly known commercial lap truing machines. This lap truing machine comprises a base 8 having Spaced uprights I and I in which is pivotally supported. as illustrated at I and}, ayoke ll having a centrally located bearing ll thereon in eccentric relation with a line extending through the spaced bearings 8 and 0. The base I is provided with a slideway I! in which a slide plate It is mounted. ThisisbestshowninFlgJ. Theplate it is provided with a central hearing it in which the pivot projection ll of a plate member I. is rotatably supported. The plate member ll is, in turn, provided with a slideway ll to which a slide plate It is slidably connected. The slide plate II has the base" of an upright 2| pivotally secured thereto by a suitablv pivot member II. The plate member ltisproviued withaworm scar sector I! meshing with a worm gear 28.

of. The bearing 21 is adapted to support a lap,

which is to be surfaced. The bearing i I, in conventional use. is adapted to support the cutting tool for engaging the lap 28 when the yoke iliis reciprocated about its pivots 8 and 9. This causes the cutting tool to move in vertical strokes transversely of the face of the lap 28 and such motion is imparted to the yoke through a power driven disc 29 having a connecting rod eccentrically pivoted thereto as illustrated at 3|. The connecting rod 30 is connected with motion transfer lever means to the yoke iii which through rota tion of the disc 29 and the eccentric pivot 8! will cause the connecting rod 30 to operate said motion transfer .lever means 32 and cause the yoke iii to he reciprocated about its pivot members 8 and 9. The extent of said reciprocal movement is sufilcient to cause the cutting tool to traverse the entire width of the face of thelap 2B which is to be machined. Simultaneous to this function a power driven adjustable stroke awl 23 en a es the ratchet wheel 25 and advances said ratchet wheel an amount equal to the tooth dis lacement of the pawl. A suitable sprin ressed plunger 3| havin an en a ement ortion with teeth of th ratchet wheel is adapted to hold said ratchet wheel in advanced nosition. 'his causesthe ratchet wheel 25 to rotate and to. in turn. rotate the worm gear 23. The worm ear 22 which is in rneshed relation with the ear sector 22 will cause the support 20 to be swung in an are about the pivotal member I. The above causes the lap to move in a direction substantially normal to the path of movement of the reciprocatin cutting tool carried by the yoke in. This is merely eneral escription of a conventional lap truinq machin During such rotarv movement of the plate is he base I! of the upright 20 is locked in fixed r lation with the slide plate is bv any suitable means not shown.

It is to be understood that prior to causin he cutting tool to reciproca e tra nsversely of the face of the lap 28 and to simultaneousl cause sai lap to move in a ath substan allv normal .to t e a h of movement of he cuttin tool the lap and cuttin tool are initially adiusted relative to each other. that is. with respect to the center of the.

pivotal supports l5 and Band 9 respectively to.-

ob ain the curve generations desired.

It is also to be understood that thelap SllDnOrt 20 is initially adiusted in a sid wise direction an the lap. Again the above is merely descriptive of a conventional lap truing machine. The length assaue of the slidcway ll controls the limit of curvature as to long radius curve generation.

The above describes the forming of a concave surface on the lap 22. when it is desired to generate a convex curvature the lap is supported by the bearing H and the cutting. tool is supported by the bearing 21 causing the curvature opposite to the direction of the concave curvature described above to be generated.

The slide plate II is movable longitudinally of the slideway I! by a suitable conventional thread adjustment member 35. The slide member I: is movable longitudinally of the slideway l2 by a I similar conventional adjustable screw member II operated by'the hand lever 21.

The device embodying the invention, which is the form of auxiliary attachable parts, comprises an upright member 28 which may be detachably connected with the base I by any suitable means, such as bolts 39, as shown in Figs. 2 and 3. The upright 38 is provided with spaced openings 40 and II. The opening 40 is adapted to support a bar member 42 having a pivot coupling 43 adjacent one end thereof to which a hollow rod-like member 44 is pivotally attached, as indicated at 45. The hollow rod-like member has an additional rod-like portion 46 in telescopic'relation therewith, which additional rod-like member 48 is threadedly connected with the base I! of the up-' right 20, as shown at 41 in Fig. 3. A suitable clamp screw 48 is provided for locking the rod 46 in proper adjusted relation with the hollow rod-like member 44, and a suitable clamp screw 82 looks the bar-like member 42 in the opening or'bearing II.- It is to be, noted that the axis of the pivot is disposed substantiallyin a vertical direction so as to permit sidewise movement of the base it carry-' ing theuprlght 2U.

The-opening II is adapted to receive an adjustable bar member 49 having a bracket -mem,- ber 50 pivotally attached thereto as illustrated at 5]. The said bracket member is provided with spaced bearing members I2 intowhich spaced rod-like members 52 extend and which are locked therein by suitable set screws or the like to a bracket member 58, having a tool carrying head or holder 51 formed integrally therewith and in which a suitable cutting tool or the like 58 is secured. The head or holder 57 is so formed as to permit the attachment of the lap 22 thereto instead of the tool 58 if desired. The bracket member 56 has a driving link l9 pivoted thereto as illustrated at 60. The said driving link is, in turn, pivotally connected to a bar memberv GI as illustrated at 62. The bar member BI is adapted to extend within and to be secured in the hearing H of the yoke II.

With the auxiliary attachment, such as set forth above, the feed screw means 35 is disassociated with the slide ll so as to permit said slide it to be moved freely longitudinally'of the slideway II. The base i9 is disconnected from the plate l8 so as to permit free pivotal movement of the base It relative to the pivot 2|.

Power is then applied to rotate .the disc 29 and" to operate the drive pawl 22. As the disc 29 rotates, the connecting rod 30 through the motion transfer lever means 32, imparts an up and down reciprocating movement to the yoke II. This movement is transferred through the link all of the objects and advantages of the inven- 89 to the bracket" and causes the cutting tool 58 to reciprocate in a vertical direction about the center as the center of rotation. This causes the tool to move about an arc whose radius of curvature is equivalent to the distance between the center of the pivot BI and the point of the cutting tool 88. Simultaneous to this up and down movement of the tool the upright 20,

carried by the base l8, and which is threadedly connected with the telescoping rod- like members 48 and 44 respectively, will be caused to move in a sidewise direction about an arc swinging'about the pivot 45 as the center of rotation. This causes the lap 28 to move in said are and the radius of curvature generated along the horizontal meridian of the lap 28 will be equivalent to the distance between the center I and the point of the cutting tool measured along a line parallel with the axis of the rod- like members 44 and 46 and intersecting a plane parallel to that line and touching the point of the cutting tool. This arcuate movement is imparted to the lap 28 through the combined sliding movement of the plate l8 on the slideway l1 and the pivotal movement on the base is relative to the plate l8,

It is to be understood that the radius of curvature generated along the vertical meridian by the-stroke of the cutting tool may be varied by loosening the set screws 54 and 55 and by adjusting the bar member 49 inwardly 'of the hearing 4i and simultaneously causing the bearing 52 to be adjusted inwardly longitudinally of the spaced rod-like members 53. When the required radius of curvature is obtained the respective set screws 54 and 55 are moved to locking position. Independently of this adjustment. the curvature generated in the horizontal meridian through the horizontal movement of the lap may be controlled by loosening the set screws 48 and 63 respectively whereby the hollow rodlike member 44 is moved inwardly longitudinally of the rod-like portion 46 which, in turn, simultaneously moves the bar portion 42 inwardly of the opening or bearing 40. When the proper radius of curvature is obtained the respective set screws 48 and 63 are moved into proper adjusted position. Suitable gauge means may be provided for obtaining accurate adjustments as is conventionally employed and commonly known in the art. The bar member 6| is secured in adjusted position in the bearing II by a suitable set screw or the like 64.

Prior to starting the cutting operation it is to be understood that by operation of the hand lever 26 the lap 28 may be moved sidewise an amount sufficient to clear the tool which, when the cutting operation is started, the said cutting tool will traverse the entire face of the lap 28. This is a conventional adjustment commonly known in the art.

'Iheabove describes the method of formingconcave laps 28. When it is desired to form convex laps the cutting tool 58 is supported by the bearing 21 and the lap 28 is supported by the head 57.

With the above arrangement, it is possible to generate surface curvatures of a considerably longer radius of curvature than is possible with the initial conventional curve generating machine and this therefore greatly increases the obtainable range of curvatures.

From the foregoing description it will be seen that simple, eflicient and economical means and methods have been provided for accomplishing machine having means formoving a work sup-- port and a tool support in substantially perpendicularly related directions of movement, said device comprising a bracket attachable to the machine and having spaced bearings therein, means adjustably supported in said bearings, a rod-like member pivotally connected to one of the means adjustably supported in said bearings and having means for attachment to one of the supports of the machine for causing said support to move in a path about the center of the pivot of said rod-like member, a second rodlike member pivotally connected to the other of said adjustabl means in said bearings and having means for attachment to the other of said supports of the curve generating machine for causing said support to move about the center of the pivot of said latter rod-like member when th said supports are moved in said perpendicularly related directions.

2. A device for use with a curve generating machine having means for moving a work support and a tool support in controlled directions, said device comprising a bracket having means for attachment to the machine and having spaced bearings therein, a bar-like portion adjustably mounted in each of said bearings, each having a pivotal connection adjacent one end thereof, a plurality of rod-like members,

one pivotally connected to each of the bar-like portions, one of said rod-lik members having telescoping portions, means for securing said telescoping portions in fixed relation with each other, one of said rod-like members having means for attachment with one of the supports of the curve generating machine and the other of said rod-like members having a holder por tion adjacent the end thereof opposed to its pivotal connection with its respective bar-like portion and link means connecting said holder portion with the other of said supports of the curve generating machine.

3. A devic for use with a curve generating machine having means for moving a work support'and a tool support in substantially perpendicularly related directions, said device embodying a detachable bracket having spaced bearings therein, means adiustably carried by said spaced bearings having pivotal means adjacent one end thereof, rod-like members pivotally connected with each of the respective pivotal means, one of said rod-like members being detachably connected adjacent its opposed end with one of the supports of the machine for controlling the path of movement of said support in its direction of movement and the other of said rod-like members having a holder portion thereon, means adjustably suprality of rod-like members having pivotal connections adjacent one end thereof to said means adjustably supported in said bearings, one of said rod-like members being attached to the work support and another of said rod-like members being attached to the tool support and means for moving said work and tool supports relative to each other in said substantially perpendicularly related paths of movement.

5. A device of the character described comprising a work support and a tool support movable in perpendicularly related directions, a bracket having spaced bearings therein, a barlike portion adlustably supported in each of said bearings and having a pivotal connection adjacent one end thereof, a rod-like member pivotally connected with each oi the bar-like wnLmM J. JOYCE; GEORGE w. JACKSON.

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