US2298496A

US2298496A - Lens grinding machine

Info

Publication number: US2298496A
Application number: US406077A
Authority: US
Inventors: Metzger Reinhardt Frederick
Original assignee: Individual
Current assignee: Individual
Priority date: 1941-08-09
Filing date: 1941-08-09
Publication date: 1942-10-13
Anticipated expiration: 1959-10-13

Description

Oct. 13, 1942. R, F. METZGER LENS GRINDING MACHINE Filed Aug. 9, 1941 2 Sheets-Sheet l m Rm 0M F H m m V. N0 f A Tm wr mm A Oct. 13, 1942. R, F. METZGER LENS GRINDING MACHINE 2 Sheets-Sheet 2 Filed Aug. 9, 1941 E Q w INVENTOR ATTCR Y R E G m M M 0 P WY s M m n Patented Get. 13, 1942 a er orrlcs a. and.

18 Claims.

This invention relates to machines for grinding peripheral edges of lenses to form at said edges mounting frame engaging lugs, particularly in lens mountings as specifically described in my prior Patent #1191504, issued April 16, 1940; and the object of the invention is to provide a machine of the character described with a lens holding frame and two pairs of spaced grinding wheels with means for moving the frame to bring the lens successively into operative engagement with the two pairs of grinding wheels in performing two distinct operations upon the periphery of the lens in forming lugs in predetermined position on opposed edges of the lens-es; a further object being to provide in combination with the lens supporting frame a gage device controlling and regulating the depth of cut in the lens in forming said lugs, and means automatically moving the gage into inoperative position in performing the successive grinding operations upon the lens; a further object being to provide means for intermittently resurfacing the grinding wheels; and with these and other objects in view the invention consists in a machine of the class and for the purpose specified, which is simple in construction, efficient in use; and which is constructed as hereinafter described and claimed.

The invention is fully disclosed in the following specification, of which the accompanying drawings form a part, in which the separate parts of my invention are designated by suitable reference characters in each of the views, and in which:

Fig. 1 is a plan view of a machine made according to my invention with part of the construction broken away.

Fig. 2 is a section substantially on the line 2-2 of Fig. 1.

Fig. 3 is a view similar to Fig. 1, showing only part of the construction with parts in a different position.

Fig. 4 is a View similar to Fig. 2, showing parts in a different position.

Fig. 5 is a partial section on the line 5-5 of Fig. 1, illustrating the parts on an enlarged scale.

Fig. 6 is a View similar to 5, showing the parts in a different position; and,

Fig. 7 is a perspective view of one end portion of a lens illustrating a lug formed on one edge of the lens by the machine.

In the grinding of peripheral edges of lenses to form projecting lugs or the like thereon, it has been the practise to first grind the lens in one direction to reduce the thickness thereof in forming the lug, and then to support the lens, usually by hand, on another grinding wheel to perform the other grinding operations thereon. In these methods of procedure, considerable time was required to perform necessary grinding operations, and furthermore, many inaccuracies in the proper formation and location of the lugs have been experienced. It is the purpose of the present invention to provide a machine wherein a lens, when once properly set in the machine or in a supporting member or frame for the lens, could then be moved by said member or frame in properly alined position with respect to predetermined spaced pairs of wheels in performing the two grinding operations necessary to produce the resulting lug.

With a machine of this type and kind, the two lugs may be formed and accurately positioned on a lens in less than a minute, at least with the average type and kind of lens. With thicker lenses,' 2. little more time is required in performing the grinding operations.

While the machine is generally adaptable for use in performing two distinct grindingoperations upon various types and kinds of workpieces, in illustrating one adaptation of the invention, the machine shown in the accompanying drawings has been constructed to produce projecting lugs of a specific type and kind upon peripheral edges of eyeglass lenses; particularly to adapt such lenses for mounting in frames of the type and kind disclosed in the patent hereinbefore mentioned.

The machine comprises a base plate It which can be mounted on a table, bench, or other support; and this base has a large rectangular portion i i at one end with a reduced extending part E2 at the other end. On the end I! of the base is arranged an electric motor It, on the shaft of which is a pulley it around which passes a belt is, which in turn passes around a larger pulley secured to one end of a drive shaft H. The shaft H is supported in upstanding bearings is on the base plate in, and one of these hearings has a trough extension 19 in which a sponge or other water saturated body 20 is arranged to apply moisture to the periphery of two pairs of grinding wheels 2l--22, 2324. The wheels 2!, 22, are spaced closely to each other as indicated at 25, and this spacing controls the thickness of the resulting lug 26 to be formed on the peripheral edge of an eyeglass lens, part of which is shown at 21 in Fig. 7 of the drawings. The wheels 23, E i, are spaced apart as seen at 28, and this spacing controls the length of the resulting lug 26.

At this time it will be understood that the centers between the

spaces

25, 28, are predetermined in order to regulate the positioning of the lug 26 on the edge of the lens and with respect to side surfaces thereof. The spacing of the various grinding wheels on the shaft I! will be controlled by the spacing rings or collars 29 disposed intermediate adjacent wheels and between the pairs of wheels, a nut 30 being provided at one end of the shaft to support the wheels in position against a flange 3|. It will thus be seen that replacement of the grinding wheels may be readily accomplished.

At the free end of the extension l2 are upwardly extending bearings 32 in the upper portion of which is pivoted as seen at 33 the yoke end 34 of a swinging frame 35. The frame 35 is comparatively narrow, and swings between the pairs of wheels; the frame having spaced bearings 36 and 31 in which a rod 38 is slidably supported.

Mounted on the rod 38 is a swingable workpiece supporting and operating member or element 39 comprising a. plate portion 46 having bearings 4! and 42 coupled with the rod 38. Pivoted as seen at 43 is a top workpiece engaging jaw 44, and pivoted within a recess 45 of the plate 40 is another workpiece engaging jaw 46; the latter being pivoted as seen at 41. disposed between the jaws to normally separate the same. A screw pin 49 is pivoted to the jaw 46 as seen at 56 and this pin extends through a slot in the jaw 44. A large milled nut 52 is arranged on the screw 49, and by tightening this nut, the jaw 44 is first moved downwardly to bring a cushioned seat 53 on the inner surface of the free end thereof into engagement with a workpiece lens 54 adjacent one edge portion thereof, and to feed the lens into gripping engagement with the cushioned end 55 of an adjustable stop screw 56, the latter being supported in the member 39 adjacent the pivot 42.

On the inner surface of the jaw 44 are two other cushion blocks 51 which cooperate with corresponding alined blocks 58 on the jaw 46. After engagement of the lens 54 between the cushioned

blocks

53, 55, the continued rotation of the screw 52 will operate to draw the jaw 46 upwardly, bringing the cushion blocks 51, 56, in firm engagement with the lens adjacent the opposed edge portions thereof.

The frame 35 has substantially centrally thereof oppositely directed lugs 59, one of which is shown in Fig. 1 of the drawings, and the other in Fig. 3; and in these lugs are adjustable stop screws 69, 6|, which check the swinging movement of the member or element 39 in the frame in both directions. Pivoted to the frame 35 below and adjacent the bearing 31 as seen at 62 is a gage plate or shim 63 in the form of a hookshaped plate, the thickness of which controls the depth of the out to be made in the lens or workpiece in forming the resulting lug 26; and this gage plate may be changed from time to time to suit different types and kinds of operations to be performed.

Secured in the bearing 31 is a hardened pin 64, and adjustably mounted in the bearing 4| are two

pins

65 and 66, both of which are adapted to be moved into registering position with the pin 64 in the two different positions assumed by the member 39 as clearly illustrated in Figs. 5 and 6 of the drawings.

In the operation of setting the workpiece or lens A coil spring 48 is 54 in the machine between the jaws 44 and 46, the shim or gage 63 is first swung into the position shown in Fig. 5 with the member 39 in the position shown in said figure; and the frame supported in the horizontal position indicated in Fig. 2 by means later described; and a suitable mark or markings on the lens are brought into registering position to positively locate the position of the lug along the edge 21a of the lens, note Fig. 7. When properly alined, the lens is moved into abutting engagement with the periphery of the

wheels

23, 24, and while held in this position, the screw 52 is tightened to first close the jaw 44 and grip the lens between the cushioned blocks 53, and then to grip the lens between the pairs of blocks 51, 58, by the upward or closing movement of the jaw 46. After being secured in this position, the member 39 is swung vertically on the axis 38 which rotates in the bearings 36, 31 to move the member 39 from the position shown in Fig. 5 to the position shown in Fig. 6, in which operation the member 39 automatically engages the gage plate 63 to throw it out of alinement with the pin 66 and the pin 64, thus permittin the member 39 to be fed in the direction of the grinding wheels to the degree measured by the space left between the

pins

64, 66, by the removal of the gage 63.

In swinging the member 39 in the manner above described, the workpiece or lens 21 is brought into registering position with the groove 25 between the grinding wheels 2 I, 22, and it is preferable in this swinging operation that the frame 35 be dropped from its horizontal position to a downwardly inclined position as is indicated in Fig. 4 of the drawings. This dropping of the frame 35 is controlled by a lever 61', the axis 68 of which is pivoted in a recessed portion 69 of the base. Secured to the axis 68 of the lever within the recess is a wide cam arm 19, the general side elevation of which is clearly illustrated in Fig. 2 of the drawings. At one side and upon the upper surface of this arm, adjacent the axis 68, is a narrow raised stop II, note Figs. 1 and 3; the latter being movable into a position to one side of the entire frame 35 so as to allow the frame to drop onto the cam arm 10 as seen in Fig. 4 of the drawings; whereas, by shifting the lever across the frame, the stop 16 can be brought into position beneath the frame to support the same in substantially horizontal position as seen in Fig. 2.

With the frame 31 in the dropped position and with the member 39 in the position of Figs. 4 and 6, the frame 35 may be swung vertically on the pivot 33 to pass the peripheral edge of the workpiece over the periphery of the wheels 2| and 22 in forming the grooves upon inner and outer surfaces of the lens to control the thickness of the resulting lug 26. In operating upon relatively thin lenses, this operation can be performed in a single upward swinging movement of the frame, feeding the member 39 in the direction of the grinding wheel in this operation; whereas in operating upon thicker workpieces, the completed operation may require two or more passes or movements of the workpiece relatively to the grinding wheels.

After the above operation has been completed, the member 39 when drawn away from the grinding wheels is then swung into the position shown in Fig. 5; and at the same time the lever 61 is actuated to bring the stop H in position to engage the frame 35 in its downwardly swinging movement to check it at the horizontal position shown in Fig. 2 of the drawings. Thereafter, the member 39 is moved in the direction of the wheels 23, 24', and the second grinding operation will be performed cutting away the edge 21a beyond the ends of the lug 25, which latter cut will be of the same depth as the first cutting operation and con trolled by the same gage, the pin 65 striking the pin 64 at the limit of the cutting operation. In the last named swinging movement of the member 39. it will be understood that the gage plate 33 remains in its inoperative position.

At the completion of the above described operation, the workpiece is removed by loosening the screw 52 which will separate the

jaws

36, 54; and the lens may be replaced between the jaws exposing the opposed edge thereof, and the above operation repeated in forming a corresponding lug on said other edge. In the beginning of this second operation, it will be understood that the gage 63 is moved first into its blocking position as seen in Fig. 5. From time to time the peripheral surfaces of the grinding wheels 2| and 2% may be renewed by movement of a diamond or other finishing tool 12 over the surfaces of the wheels. The diamond 712 is adjustably supported on a screw 73 mounted in a raised portion Hi of an arm E5; the arm carrying at its pivot end a shoe l5 slidable in a channel H and retained in centralized alinement with the two pairs of grinding wheels by set screws 18, note Fig. 1 of the drawings. The forward end of the arm 75 is channeled as seen at T9 to slidably engage a guide and supporting rail 89 upon which the free end of the arm is freely slidable.

It will be apparent that any means of resurfacing or shaping the grinding wheels may be provided to give the required or desired contour thereto, consistent with the particular type and kind of workpiece operated upon. In the construction shown, the arm is swung by the turning of a screw 8| arranged in a support 82, and having a pinion 83 engaging a rack 8d slidable through the support.

When the member 35 is in the position shown in Figs. i and 6, the upward swinging movement of said member to move the workpiece across the periphery of the grinding wheel is accomplished by raising the lever 51; the cam arm 70 operating upon the lower surface of the frame 35 to raise said frame together with the member 39.

This operation will be performed by one hand, c1

while the other hand of the operator rests upon the member 39 to feed the same in the direction of the grinding wheels. In the operation of grinding the workpiece between the

wheels

23, 24, the lever 61 remains at rest, and one hand of the operator is suficient to feed the member ea, and the workpiece, in the direction of these wheels.

From the machine as described above, it will be apparent that a workpiece when once properly al ned in the machine and at one grinding station, can be moved and automatically alined in a second grinding station so that two distinct grinding operations can be quickly and accurately performed. Where a large number of lenses are to be produced with the same positioning of the '3.

lugs thereon, or with respect to opposededges thereof, a single setting of the machine is all that is necessary, even though the lenses may vary in thickness. The reason for the foregoing is that the adjustment screw 55 serves to definitely space the inner surface of the lens with respect to the resulting lug to be formed; and this spacing is preferably adhered to notwithstanding the thicknesses of the lenses operated upon in order to provide the most desirable and practical mounting of the. frames. thereon. In other words, the machine will require independent adjustment or setting only when the shape and contour and size of the lug is changed; and further in placing the lug on lenses of extreme irregular contours as com-pared with the more or less standardized lens illustrated.

By mounting the complete machine on a single and substantially heavy base, the complete unit may be conveniently shifted about on a workbench or table, and the entire machine is of such simple design and construction as to make it possible to produce the same at a nominal cost, and not withstanding its simplicity, the machine is substantially foolproof in operation and will eliminate the necessity of employing highly skilled operators in performing the desired operations.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A grinding machine comprising two pair of grinding wheels, the wheels in each pair being spaced apart to regulate grinding operations performed on a predetermined workpiece, means movably supporting a workpiece to aline the same with each pair of grinding wheels in performing two different grinding operations upon the workpiece in producing on the resulting ground product a protruding member the dimensions of which as to thickness and length are controlled by the spacing of each pair of grinding wheels.

2. A grinding machine comprising two pair of grinding wheels, the wheels in each pair being spaced apart to regulate grinding operations performed on a predetermined workpiece, means movably supporting a workpiece to aline the same with each pair of grinding wheels in per-- forming two different grinding operations upon the workpiece in producing on the resulting ground product a protruding member the dimensions of which as to thickness and length are controlled by the spacing of each pair of grinding wheels, and means cooperating with said first named means controlling the depth of the cut in the workpiece in regulating the extent of projection of said member on the finished product.

3. A grinding machine comprising two pair of grinding wheels, the wheels in each pair being spa'ced'apart to regulate grinding operations performed on a predetermined workpiece, means movably supporting a workpiece in producing on the resulting ground product a protruding member the dimensions of which as to thickness and length are controlled by the spacing of each pair of grinding wheels, means cooperating with said first na'med means controlling the depth of the cut in the workpiece in regulating the extent of projection of said member on the finished prodnot, and means adjustable in said first means controlling the spacing of one surface of a workpiece with respect to one pair of grinding Wheels.

4. A grinding machine comprising one pair of closely spaced grinding wheels, another pair widely spaced grinding wheels arranged i spaced relation to the first named wheels, workpiece supporting member, means for movingsaid member to bring a workpiece in operative engagement with each pair of wheels in alineinent with the spaced sections thereof, gage means cooperating with said member in mounting a workpiece therein, and means limiting movement of the workpiece in the direction of each pair of grinding wheels upon the movement of the gage means into inoperative position.

5. A grinding machine comprising one pair of closely spaced grinding wheels, another pair of widely spaced grinding wheels arranged in spaced relation to the first named wheels, a workpiece supporting member, means for moving said member to bring a workpiece in operative engagement with each pair of wheels in alinement with the spaced sections thereof, gage means cooperating with said member'in mounting a workpiece'therein, means limiting movement of the workpiece in the direction of each pair of grinding wheels upon the movement of. the gage means into inoperative position, a swinging frame in which said member is movably supported, means supporting the frame to maintain the workpiece in predetermined position with respect to the axis of one pair of grinding wheels in the operation of grinding the workpiece, and means for swinging said frame to move a workpiece over the periphery of the other pair of grinding wheels in the operation of grinding said workpiece.

6. A grinding machine comprising one pair of closely spaced grinding wheels, another pair of widely spaced grinding wheels arranged in spaced relation to the first named wheels, a workpiece supporting'member, means for movin said member to bring a workpiece in operative engagement with each pair of wheels in alinement with the spaced sections thereof, gage means cooperating with said member in mounting a workpiece therein, means limiting movement of the workpiece in the direction of each pair of grinding wheels upon the movement of the gage means into inoperative position, a swinging frame in which said member is movably supported, means supporting the frame to maintain the workpiece in predetermined position with respect to the axis of one pair of grinding wheels in the operation of grinding the workpiece, means for swinging said frame to move a workpiece over the periphery of the other pair supporting member, means for moving said memher to bring a workpiece in operative engagement with each pair of wheels in alinement with the spaced sections thereof, gage means cooperating with said member in mounting a workpiece therein, means limiting movement of the workpiece in the direction of each pair of grinding wheels upon the movement of the gage means into inoperative position, a swinging frame in which said member is movably supported, means supporting the frame to maintain the workpiece in predetermined position with respect to the axis of one pair of grinding wheels in the operation of grinding the workpiece, means for swinging said frame to move a workpiece over the periphery of the other pair of grinding wheels in the operation of grinding said workpiece, said member having an adjustable workpiece support for alining the workpiece with respect to the first named pair of wheels, and said member having a pair of workpiece gripping jaws, one of which directly cooperates with said adjustable workpiece support in securing the workpiece in said member.

8. In a grinding machine employing two pair of spaced grinding wheels forming independent grinding stations disposed in spaced relation to each other, a workpiece supporting member, means for moving said member to positively position a workpiece mounted therein with respect to each grinding station in performing two distinct grinding operations on the workpiece supported in said member, said member being movable toward and from the wheels at each grinding station, and adjustable stop means limiting movement of the workpiece in the direction of the wheels at each station in controlling the depth of cut formed in the workpiece at each station.

9. In a grinding machine employing two pair of spaced grinding wheels forming independent grinding stations disposed in spaced relation to each other, a workpiece supporting member, means for moving said member to positively position a workpiece mounted therein with respect to each grinding station in performing two distinct grinding operations on the workpiece supported in said member, said member being movable toward and from the wheels at each grinding station, adjustable stop means limiting movement of the workpiece in the direction of the wheels at each station in controlling the depth of cut formed in the workpiece at each station, and means for swinging the workpiece over the surface of the wheels at one grinding station.

10. In a grinding machine employing two pair of spaced grinding wheels forming independent grinding stations disposed in spaced relation to each other, a workpiece supporting member, means for moving said member to positively position a workpiece mounted therein with respect to each grinding station in performing two distinct grinding operations on the workpiece supported in said member, said member being movable toward and from the wheels at each grinding station, adjustable stop means limiting movement of the workpiece in the direction of the wheels at each station in controlling the depth of cut formed in the workpiece at each station, means for swinging the workpiece over the surface of the wheels at one grinding station, and means comprising relatively movable jaws for supporting workpieces of irregular contour in said member.

11. In a grinding machine employing two pair of spaced grinding wheels forming independent grinding stations disposed in spaced relation to each other, a workpiece supporting member, means for moving said member to positively position a workpiece mounted therein with respect to each grinding station in performing two distinct grinding operations on the workpiece supported in said member, said member being movable toward and from the wheels at each grinding station, adjustable stop means limiting movement of the workpiece in the direction of the wheels at each station in controlling the depth of cut formed in the workpiece at each station, means for swinging the workpiece over the surface of the wheels at one grinding station, said last named means including an adjustable element for alining the workpiece with respect to the wheels at one of said grinding stations.

12. In a grinding machine employing two pair of spaced grinding wheels forming independent grinding stations disposed in spaced relation to each other, a workpiece supporting member,

means for moving said member to positively position a workpiece mounted therein with respect to each grinding station in performing two distinct grinding operations on the workpiece supported in said member, said member being movable toward and from the wheels at each grinding station, adjustable stop means limiting movement of the workpiece in the direction of the wheels at each station in controlling the depth of cut formed in the workpiece at each station, means for swinging the workpiece over the surface of the wheels at one grinding station, said last named means including an adjustable element for alining the workpiece with respect to the wheels at one of said grinding stations, and means for limiting the movement of said member in one direction when moving the workpiece into registering position with each grinding station.

13. In a grinding machine of the character described, a swinging frame, a workpiece supporting member, common means for slidably and swingably mounting said member in said frame, adjustable means on said frame limiting the swinging movement of said member in two directions, adjustable means checking sliding movement of said member in moving a workpiece supported in said member in the direction of a grinding element of the machine.

14. In a grinding machine of the character described a swinging frame, a workpiece supporting member slidably and swingably mounted in said frame, adjustable means on said frame limiting the swinging movement of said member in two directions, adjustable means checking sliding movement of said member in moving a workpiece supported in said member in the direction of a grinding element of the machine, and a gage cooperating with said last named means in controlling the depth of cut to be formed in the workpiece.

15. In a grinding machine of the character described a swinging frame, a'workpiece supporting member slidably and swingably mounted in said frame, adjustable means on said frame limiting the swinging movement of said member in two directions, adjustable means checking sliding movement of said member in moving a workpiece supported in said member in the direction of a grinding element of the machine, means movable transversely with respect to the swinging frame to support said frame in horizontal position, and said means including means engaging the frame to swing the same and the workpiece supporting member thereon through a predetermined arc in moving a workpiece supported in said member over the surface of a grinding element of the machine.

16. In a grinding machine of the character described a swinging frame, a workpiece supporting member slidably and swingably mounted in said frame, adjustable means on said frame limiting the swinging movement of said member in two directions, adjustable means checking sliding movement of said member in moving a workpiece supported in said member in the direction of a grinding element of the machine, said member having two independently pivoted workpiece engaging jaws, jaw operating means comprising a screw pivoted to one jaw and a nut engaging the other jaw to independently move the jaws into operative engagement with the workpiece, and an adjustable workpiece support between which and one of said jaws a workpiece is adapted to be supported.

17. In a lens grinding machine of the character described a lens supporting member comprising an elongated body, an adjustable lens support at one end of the body, a jaw pivoted to the other end of the body and cooperating with said support in clamping one edge portion of a lens insaid member, another jaw pivoted to said body and movable toward the first named jaw to clamp the otheredge portion of a lens therebetween, a screw pivoted to the last named jaw, a nut adjustable on said screw and cooperating with the first named jaw in moving the jaws into operative engagement with a lens, and a spring disposed between said jaws to separate the same upon the loosening of said nut to remove a lens from said member.

18. In a grinding machine employing a workpiece supporting member movable into two independent grinding stations in performing two grinding operations on the workpiece while supported in said member, each station having grinding means, means alining a workpiece supported in said member with the grinding means at each station, said member being movable toward and from the grinding means at each station, and means limiting the movement of said member in the direction of the grinding means at each station in controlling the depth of cut formed in the workpiece at each station.

REINHARDT FREDERICK METZGER.