US2470021A - Grinding and polishing machine - Google Patents

Description

y 1949. P. DE v. DAVAUCOURT 2,470,021

GRINDING AND POLISHING MACHINE Filed Nov. 20, 1944 s sheets-Sheet 1 Ifiwimtor .724'91'229032 Wig! d vaacfozzri By a Attorneys y 949. P. DE v. DAVAUCOURT 2,470,021

GRINDING AND POLISHING MACHINE Filed Nov. 20, 1944- I 5 Sheets-Sheet 2 Inventor P. DE v. DAVAUCOURT 2,470,021

GRINDING AND POLISHING MACHINE May 10, 1949.

Filed NOV. 20, 1944 3 Sheets-Sheet 3 Inventor jab/re aZe aflzzaadaazri v I By @Mm Patented May 10, 1949 GRINDIN G AND POLISHING MACHINE Pierre de Vitry dAvaucourt, Bainbridge, Pa., as-

signor of fifty per cent to William Boston Bailey,

Huntington, W. Va.

Application November 20, 1944, Serial No. 564,252

3 Claims. I

This invention relates to a grinding and polishing machine, and more particularly to such machine adapted to be utilized in the shaping, grinding and polishing of glass, as, for example, opti cal lenses, or the like.

A primary object of this invention is the provision of an improved grinding and polishing machine adapted to shape a lens, or the like, to form a toroidal surface, the major and minor axes of curvature of which may differ. A further object of the invention is the provision of an improved device having guide means associated therewith, whereby the device may be adjusted to shape an irregular toroidal surfaced lens, or the like, having two axes of difierent radii of curvature, as defined by the guides, the two axes being simultaneously formed.

A still further object of the invention is the provision of such device which will he sturdy and durable in construction, reliable and efiicient in operation, and relatively simple and inexpensive tomanufa-cture and assemble.

Other objects reside in the combinations of elements, arrangements of parts, and features of construction, a11 as will be more fully pointed out hereinafter and disclosed in the accompanying drawing-s, wherein there are disclosed two preferred embodiments of this inventive concept.

In the drawings:

Figure 1 is a side elevational view of one form of the device embodying features of this invention,

Figure 2 is a top plan view of the device disclosed in Figure 1,

Figure 3 is a side elevational view of a modified form of construction,

Figure 4 is a diagrammatic view disclosing one form of toroidal surface adapted to be generated by this device,

Figure 5 is a sectional view taken along the line 5-5 of Figure 3, as viewed in the direction indicated by the arrows,

Figure 6 is a plan view of one form of lens adapted to be ground by the device,

Figure '7 is a sectional view taken substantial- 1y along the line 11 of Figure 6, and

Figure 8 is a sectional view taken substantially along the line 88 of Figure 6.

Similar reference characters refer to similar parts throughout the several views of the drawings.

Having reference now to the drawings, there is generally indicated at I 0 a suitable base from which extend upwardly supporting members ll, between which arepositioned a pair of transin verse supporting rods [2. Positioned on rods 12" and having grooved ends receiving same, is a block l3 Which carries an upright work support l lupon which is adapted to be mounted a lens IE, or the like, to be ground. The work support i4 is provided with an internal threaded bore, adapted to be engaged by a screw l-fi controlled by an operating handle l1 at its lower-end, for varying the height of the lens l5 and the work support l4. Suitable means are provided (not shown) for the introduction of any desired grinding or cooling fluid to the lens -I 5.

Supports or upright standards I! and it; rise from the block i3, and have removably mounted thereon, in any desired manner, guides 19 and 26 of any desired configuration, it being understood that guides of suitable curvature may be provided for any desired type of work, in the grinding of a lens, or the like, either convex or concave.

Mounted for longitudinal movement on rods I2 is a second block 25, provided with suitable bores adapted to slidably engage or surroundthe rods l2, and carrying an upright supporting member 25, to which are pivotally secured, as on the projecting ends of an axle or horizontal pivot axis 21, :a pair of connected parallel extending arms 28 extending overthe lens.

Pivotally secured between the extremities of arms 28, as on an axle or pivot axis 29, is an electric motor 30, or the like, provided with a drive shaft 3|, on the extremity of which is mounted a lap 32. The lap 32 is removably secured to the shaft 3! and any desired type of grinding or polishing wheel, or any desired shape of lap may be suitably secured to the shaft 3!.

A downwardly and inwardly extending inclined guide feeler 35 is fixedly secured to one of the arms 28 and terminates in a ball-36 adapted to engage and follow the curved guide I9. A second guide feeler 31 extending downwardly and inwardly and terminating in a-ball 38 is secured to the axle 29 and adapted to'engage and follow the guide 20.

Means is provided 'for moving the block 25, and hence the arms 28, motor 30, and lap 32 longitudinally along the'rods l2. Such means take the form of a threaded member or adjustin'g screw 49 havingits inner extremity swivelly secured to a lug 4! carried by the block 25, and engaging in a suitable threaded aperture in its associated support ll. Anoperating handle 42 is provided to permit rotation of the threaded member' lfl.

A suitable source of power (not shown) is provided for the motor 30.

From the foregoing, the operation of the device should now be readily understandable. The lens [5, or the like, to be ground is positioned on the work support I4, and adjusted to a suitable height. Appropriate guide for the Work piece are selected and fixed on the standards H, l8 respectively. The hand wheel 52 is then turned to move the lap into its correct position near the edge of the work piece, and when the arm 28 is now dropped, feeler and guide rods 35, 31 are both resting on the guide surfaces IS, 2! near the edge on the right side in Figure 1,

After the grinding lap has been properly placed the motor is started and the lap 32 is fed over the work piece by turning shaft 50.

The operation is best explained when referring to Figure 4, showing three positions of the rotating and swinging grinding tool on the work piece.

The arms 28, the spindle 3i and the guide feelers 35, 31 and guide surfaces 19, 25 are diagrammatically indicated in the figure.

Positions A of the arms 28, A1 of the guide feeler 35, A2 of guide feelers 3? correspond to the initial position just described. Positions B, B1, B2 and C, C1, C2 are further positions of the above named members which are reached when the shaft is turned. Positions B, B1, B2 are shown in the figure as being the middle or central positions reached when the grinding tool is'halfway over the work piece. These positions correspond to an advance of the slide through the distance a. During this advance the lap, the center of gravity of which is below the pivot 29, grinds the work piece, swinging around point 29 which point simultaneously advances to position 29 when the slide 25 advances.

The simultaneous oscillatory and translatory movement is regulated by the tool guiding surfaces l9 and 20 with which the feelers are simultaneously in contact. As seen from Figure 4, during the advance of pivot 2? through the distance a, the point e, representing the point of fixation of guide feeler 55, has advanced to e, this position being determined by the advance through distance a on guide surface I9 on the other hand.

As stated, the point 29 moves simultaneously to 29. As the feeler 31 has a definite length the movement of point 29 to 29', around which the feeler pivots, entails a swinging movement of the feeler and of the lap connected with it which is however controlled by guide 28, guiding the end of the feeler 37 through the distance a". The axis of rotation of the lap then assumes the postion B2.

The advance from postion B, B1, B2 to C, C1, C2 explains itself.

The simultaneous movement of the two feelers along their guides therefore produces a predetermined combined translatory and swinging movement of the axis of the lap which results in a slow sweeping movement of the lap over the surface of the work piece. This movement is accurately regulated by the guides I9, 28 and determines the curvature of the lens in one direction, the curvature in the other direction being determined, as usual, by the curvature and position of the grinding means.

A modified form of construction is disclosed in Figures 3 and 5, wherein the lens, or other surface to be ground, is adapted to be moved with respect to the lap, rather than converse, as was the case in the foregoing modification. In

this modification, a base 50 is provided with upright supports 5!, between which extend a pair of transverse bars 52. The base 50 carries a motor 53 provided with a drive-shaft 54, adapted to carry a lap 55 or grinding or polishing wheel, or the like. The shaft 54 is provided with a suitable bore extending upwardly to the lap 55, through which may be fed lubricants or the like, introduced thereto as through a pipe 56. Suitable guide supporting members 51 and 58, secured in any desired manner to the supporting frame, carry guides 59 and 65, respectively, below bars 52.

A block 6|, provided with apertures, is adapted to be slidably positioned on the rod 52, and carries a supporting member 62, on which are pivotally mounted, as on an axle 63, a pair of connected parallel extending arms 64, between the extremities of which is pivotally mounted, as on an axle 65, a work holder 56 adapted for the retention of a lens 61, or the like.

A guide feeler ii! is secured to one of the arms 55 and engages the curved guide 59, serving to occasion pivotal movement of the arms 54 about the axle 63, while a guide feeler ll secured to work holder 55 adapted to engage curved guide 68, serves to pivot the work holder 66 about the axle 65.

Means are provided for moving the block or carriage ti along the bars or rods 52, such means taking the form of a threaded member or adjusting screw 72 having its extremity swivelly secured in a lug '13 carried by the block 6! and being passed through suitable threaded apertures in the support 5!. An operating wheel H1 is provided for rotation of the member 12.

The operation of the modification disclosed in Figure 3 is substantially identical to that described in connection with the foregoing modification, with the exception that the lap or grinding wheel 55 is located in a stationary postion, and the lens 57 is guided thereover for shaping or polishing the same by means of the curved guides 53 and 65.

From the foregoing, it will now be seen that there is herein provided an improved grinding and polishing machine, adapted for the simultaneous generation of the two axes of a toric surface, which accomplishes all the objects of this invention, and others including many advantages of great practical utility and commercial importance.

As many embodiments may be made of this inventive concept, and as many modifications may be made in the embodiments hereinbefore shown and described, it is to be understood that all matter herein is to be interpreted merely as illustrative and not in a limiting sense.

I claim:

1. In a device of the character described in combination, a frame, a grinding device carried thereby, a member transversely movable on said frame, an arm pivotally secured to said member, a work support pivotally secured to said arm, a guide-engaging arm secured to said first-mentioned arm, a second guide-engaging arm secured to said work support, and guide means carried by said frame adapted to be engaged by said lastmentioned arm, to control the pivotal movement of said work support and said first-mentioned arm to generate a toroidal surface having major and minor axes of different radii of curvature.

2. A grinding and polishing machine for toric lenses with a rotating grinding tool, the curvature of which determines the curvature of the lens in one direction, comprising a frame, guide members for longitudinal movement along said frame, a fixed support member, and a swingable member, one of the two last named members being provided with the rotatable grinding tool the other being adapted to hold the lens blank, a member longitudinally movable along the aforesaid guide members of said frame, means for producing the longitudinal movement of said member along said frame, an arm, pivotally secured to said movable member, a pivot means for securing said swingable member on said arm, two guiding surfaces arranged in fixed relation to said support member, guide feelers adapted to slide over said guiding surfaces, one of said guide feelers being attached to the arm and the other being fixedly attached to the swingable member for simultaneously controlling the swinging movement of the pivoted arm about its pivot during its advance and the swinging movement of the swingable member around said pivot, the simultaneous sliding of the feelers on the guiding surfaces determining the movement of the grinding tool relatively to the work piece.

3. In a grinding and polishing machine for toric lenses with a grinding tool mounted on a rotatable spindle, in combination, a frame, guide members for longitudinal movement along said frame, a slide member for longitudinal movement along said guide members, arms pivoted on said longitudinally movable slide member on one end,

a swingable member pivoted between said arms on the other end, a fixed support, one of the two last named members being adapted to carry the work piece and the other the rotatable spindle and grinding tool for relative grinding movement, removable guiding surfaces of different curvature adapted to be fixed relatively to the support, guide feelers carried by said pivoted arms and by the swingable member pivoted on said arms respectively, said feelers being in simultaneous sliding contact with both guiding surfaces of different curvature for determining the movement of the pivoted arm and of the swingable member on said arm during the longitudinal movement of the slide member, and means for advancing said slide member along the guide member on the frame.

PIERRE DE VITRY DAVAUCOURT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,281,001 Hazel Oct. 8, 1918 1,318,300 Robertson Oct. 7, 1919 1,448,239 Schuessler Mar. 13, 1923 2,242,664 Stone et a1. 'May 20, 1941 2,278,314 Houchin Mar. 31, 1942

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